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Firoozbahr M, Palombo EA, Kingshott P, Zaferanloo B. Antibacterial and Antibiofilm Properties of Native Australian Plant Endophytes against Wound-Infecting Bacteria. Microorganisms 2024; 12:1710. [PMID: 39203552 PMCID: PMC11357646 DOI: 10.3390/microorganisms12081710] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2024] [Revised: 08/12/2024] [Accepted: 08/14/2024] [Indexed: 09/03/2024] Open
Abstract
The wound management field faces significant challenges due to antimicrobial resistance (AMR) and the complexity of chronic wound care. Effective wound treatment requires antimicrobial dressings to prevent bacterial infections. However, the rise of AMR necessitates new antimicrobial agents for wound dressings, particularly for addressing bacterial pathogens like methicillin-resistant Staphylococcus aureus (MRSA). Endophytic fungi, known for producing diverse bioactive compounds, represent a promising source of such new agents. This study tested thirty-two endophytic fungi from thirteen distinct Australian native plants for their antibacterial activity against S. aureus. Ethyl acetate (EtOAc) extracts from fungal culture filtrates exhibited inhibitory effects against both methicillin-sensitive S. aureus ATCC 25923 (MIC = 78.1 µg/mL) and MRSA M180920 (MIC = 78.1 µg/mL). DNA sequence analysis was employed for fungal identification. The most active sample, EL 19 (Chaetomium globosum), was selected for further analysis, revealing that its EtOAc extracts reduced S. aureus ATCC 25923 biofilm formation by 55% and cell viability by 57% to 68% at 12 × MIC. Furthermore, cytotoxicity studies using the brine shrimp lethality test demonstrated low cytotoxicity up to 6 × MIC (25% mortality rate) with an LC50 value of 639.1 µg/mL. Finally, the most active sample was incorporated into polycaprolactone (PCL) fiber mats via electrospinning, with resultant inhibition of S. aureus species. This research underscores the potential of endophytic fungi from Australian plants as sources of substances effective against common wound pathogens. Further exploration of the responsible compounds and their mechanisms could facilitate the development of wound dressings effective against MRSA and innovative biofilm-resistant electrospun fibers, contributing to the global efforts to combat AMR.
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Affiliation(s)
- Meysam Firoozbahr
- Department of Chemistry and Biotechnology, School of Science, Computing and Engineering Technologies, Swinburne University of Technology, Hawthorn, VIC 3122, Australia; (M.F.); (P.K.)
| | - Enzo A. Palombo
- Department of Chemistry and Biotechnology, School of Science, Computing and Engineering Technologies, Swinburne University of Technology, Hawthorn, VIC 3122, Australia; (M.F.); (P.K.)
- ARC Training Center for Biofilm Research and Innovation, School of Science, Computing and Engineering Technologies, Swinburne University of Technology, Hawthorn, VIC 3122, Australia
| | - Peter Kingshott
- Department of Chemistry and Biotechnology, School of Science, Computing and Engineering Technologies, Swinburne University of Technology, Hawthorn, VIC 3122, Australia; (M.F.); (P.K.)
- ARC Training Centre in Surface Engineering for Advanced Materials (SEAM), School of Engineering, Swinburne University of Technology, Hawthorn, VIC 3122, Australia
| | - Bita Zaferanloo
- Department of Chemistry and Biotechnology, School of Science, Computing and Engineering Technologies, Swinburne University of Technology, Hawthorn, VIC 3122, Australia; (M.F.); (P.K.)
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Sukpanoa S, Kaewkla O, Suriyachadkun C, Papayrata C, Klankeo P, Franco CMM. Streptomyces mahasarakhamensis sp. nov., an Endophytic Actinobacterium Isolated from Jasmine Rice and its Potential as plant Growth Promoter. Curr Microbiol 2024; 81:223. [PMID: 38874598 DOI: 10.1007/s00284-024-03747-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Accepted: 05/19/2024] [Indexed: 06/15/2024]
Abstract
Two endophytic actinobacteria, strains MK5T and MK7, were isolated from the surface-sterilized root of Jasmine rice (Oryza sativa KDML 105). These strains were aerobic actinobacteria with a well-developed substrate and aerial mycelia that formed spiral spore chains. The type strains that shared the high 16S rRNA gene sequence similarity with both strains were Streptomyces naganishii NBRC 12892T (99.4%), "Streptomyces griseicoloratus" TRM S81-3T (99.2%), and Streptomyces spiralis NBRC 14215T (98.9%). Strains MK5T and MK7 are the same species sharing a digital DNA-DNA hybridization (dDDH) value of 95.3% and a 16S rRNA gene sequence similarity of 100%. Chemotaxonomic data confirmed the affiliation of strains MK5T and MK7 to the genus Streptomyces. Strains MK5T and MK7 contained MK-9(H4) as a major menaquinone; the whole-cell sugar of both strains was galactose and glucose. The strain MK5T shared 93.4% average nucleotide identity (ANI)-Blast, 95.5% ANI-MUMmer, 93% average amino acid identity, and 61.3% dDDH with S. spiralis NBRC 14215T. The polyphasic approach confirmed that strain MK5T represents a novel species, and the name Streptomyces mahasarakhamensis sp. nov. is proposed. The type strain is MK5T (= TBRC 17754 = NRRL B-65683). Genome mining, using an in silico approach and searching biosynthesis gene clusters of strains MK5T and MK7, revealed that the genomes contained genes encoding proteins relating to plant growth promotion, bioactive compounds, and beneficial enzymes. Strains MK5T and MK7 could produce indole acetic acid and solubilize phosphate in vitro.
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Affiliation(s)
- Sudarat Sukpanoa
- Faculty of Science, Department of Biology, Mahasarakham University, Kham Riang, 44150, Maha Sarakham Province, Thailand
| | - Onuma Kaewkla
- Faculty of Science, Department of Biology, Mahasarakham University, Kham Riang, 44150, Maha Sarakham Province, Thailand.
| | - Chanwit Suriyachadkun
- Thailand Bioresource Research Center (TBRC), National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Klong Luang, 12120, Pathumthani, Thailand
| | - Chanakran Papayrata
- Central Laboratory of Mahasarakham University, Mahasarakham University, Kham Riang, 44150, Maha Sarakham Province, Thailand
| | - Piriya Klankeo
- Faculty of Science, Omics Science and Bioinformatics Center, Chulalongkorn University, Pathumwan, 10330, Bangkok, Thailand
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Kaewkla O, Perkins M, Thamchaipenet A, Saijuntha W, Sukpanoa S, Suriyachadkun C, Chamroensaksri N, Chumroenphat T, Franco CMM. Description of Streptomyces naphthomycinicus sp. nov., an endophytic actinobacterium producing naphthomycin A and its genome insight for discovering bioactive compounds. Front Microbiol 2024; 15:1353511. [PMID: 38694805 PMCID: PMC11061393 DOI: 10.3389/fmicb.2024.1353511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2023] [Accepted: 04/01/2024] [Indexed: 05/04/2024] Open
Abstract
Endophytic actinobacteria are a group of bacteria living inside plant tissue without harmful effects, and benefit the host plant. Many can inhibit plant pathogens and promote plant growth. This study aimed to identify a strain of Streptomyces as a novel species and study its antibiotics production. An endophytic actinobacterium, strain TML10T was isolated from a surface-sterilized leaf of a Thai medicinal plant (Terminalia mucronata Craib and Hutch). As a result of a polyphasic taxonomy study, strain TML10T was identified as a member of the genus Streptomyces. Strain TML10T was an aerobic actinobacterium with well-developed substrate mycelia with loop spore chains and spiny surface. Chemotaxonomic data, including cell wall components, major menaquinones, and major fatty acids, confirmed the affiliation of strain TML10T to the genus Streptomyces. The results of the phylogenetic analysis, including physiological and biochemical studies in combination with a genome comparison study, allowed the genotypic and phenotypic differentiation of strain TML10T and the closest related type strains. The digital DNA-DNA hybridization (dDDH), Average nucleotide identity Blast (ANIb), and ANIMummer (ANIm) values between strain TML10T and the closest type strain, Streptomyces musisoli CH5-8T were 38.8%, 88.5%, and 90.8%, respectively. The name proposed for the new species is Streptomyces naphthomycinicus sp. nov. (TML10T = TBRC 15050T = NRRL B-65638T). Strain TML10T was further studied for liquid and solid-state fermentation of antibiotic production. Solid-state fermentation with cooked rice provided the best conditions for antibiotic production against methicillin-resistant Staphylococcus aureus. The elucidation of the chemical structures from this strain revealed a known antimicrobial agent, naphthomycin A. Mining the genome data of strain TML10T suggested its potential as a producer of antbiotics and other valuable compounds such as ε-Poly-L-lysine (ε-PL) and arginine deiminase. Strain TML10T contains the arcA gene encoding arginine deiminase and could degrade arginine in vitro.
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Affiliation(s)
- Onuma Kaewkla
- Center of Excellence in Biodiversity Research, Mahasarakham University, Maha Sarakham, Thailand
- Department of Medical Biotechnology, College of Medicine and Public Health, Flinders University, Adelaide, SA, Australia
| | - Mike Perkins
- Deparment of Chemistry, College of Science and Engineering, Flinders University, Adelaide, SA, Australia
| | | | - Weerachai Saijuntha
- Center of Excellence in Biodiversity Research, Mahasarakham University, Maha Sarakham, Thailand
- Faculty of Medicine, Mahasarakham University, Maha Sarakham, Thailand
| | - Sudarat Sukpanoa
- Department of Biology, Faculty of Science, Mahasarakham University, Maha Sarakham, Thailand
| | - Chanwit Suriyachadkun
- Thailand Bioresource Research Center (TBRC), National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Pathumthani, Thailand
| | - Nitcha Chamroensaksri
- National Biobank of Thailand (NBT), National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Pathumthani, Thailand
| | - Theeraphan Chumroenphat
- Aesthetic Sciences and Health Program, Faculty of Thai Traditional and Alternative Medicine, Ubon Ratchathani Rajabhat University, Ubon Ratchathani, Thailand
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O'Brien A, Hart J, Higgins A, Arthur I, Lee GH, Leung M, Kennedy K, Bradbury S, Foster S, Warren S, Korman TM, Abbott IJ, Heney C, Bletchley C, Warner M, Wells N, Wilson D, Varadhan H, Stevens R, Lahra M, Newton P, Maley M, van Hal S, Ingram PR. Nocardia species distribution and antimicrobial susceptibility within Australia. Intern Med J 2024; 54:613-619. [PMID: 37929813 DOI: 10.1111/imj.16234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Accepted: 08/29/2023] [Indexed: 11/07/2023]
Abstract
BACKGROUND Nocardia is a ubiquitous saprophyte capable of causing human disease. Disease is primarily respiratory or cutaneous, usually acquired via inhalation or inoculation. Under the influence of environmental and host factors, Nocardia incidence and species distribution demonstrate geographical variation. AIMS To examine for differences in Nocardia incidence within Western Australia (WA) and analyse species distribution in the context of prior published studies. To analyse antibiogram data from a nationwide passive antimicrobial resistance surveillance program. METHODS Retrospective extraction of laboratory data for Western Australian Nocardia isolates over a 21-year period. Analysis of Nocardia antimicrobial susceptibility testing data submitted to the Australian Passive Antimicrobial Resistance Surveillance (APAS) program between 2005 and 2022. RESULTS Nine hundred sixty WA isolates were identified, giving an annual incidence of 3.03 per 100 000 population with apparent latitudinal variation. The four most common species identified within WA and amongst APAS isolates were N. nova, N. cyriacigeorgica, N. brasiliensis and N. farcinica. APAS data demonstrated that all species exhibited high rates of susceptibility to linezolid (100%) and trimethoprim-sulfamethoxazole (98%). Amikacin (>90% susceptibility for all species except N. transvalensis) was the next most active parenteral agent, superior to both carbapenems and third-generation cephalosporins. Susceptibility to oral antimicrobials (other than linezolid) demonstrated significant interspecies variation. CONCLUSIONS We demonstrate geographical variation in the distribution of Nocardia incidence. Four species predominate in the Australian setting, and nationwide data confirm a high in vitro susceptibility to trimethoprim-sulphamethoxazole and linezolid, justifying their ongoing role as part of first-line empiric therapy.
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Affiliation(s)
- Aine O'Brien
- Department of Infectious Diseases, Fiona Stanley Hospital, Perth, Western Australia, Australia
| | - Julie Hart
- Department of Infectious Diseases, Sir Charles Gardiner Hospital, Perth, Western Australia, Australia
| | - Ammie Higgins
- PathWest Laboratory Medicine, Queen Elizabeth II Medical Centre, Perth, Western Australia, Australia
| | - Ian Arthur
- PathWest Laboratory Medicine, Queen Elizabeth II Medical Centre, Perth, Western Australia, Australia
| | - Gar-Hing Lee
- PathWest Laboratory Medicine, Queen Elizabeth II Medical Centre, Perth, Western Australia, Australia
| | - Michael Leung
- PathWest Laboratory Medicine, Queen Elizabeth II Medical Centre, Perth, Western Australia, Australia
| | - Karina Kennedy
- ACT Health, Canberra Hospital, Canberra, Australian Capital Territory, Australia
| | - Susan Bradbury
- ACT Health, Canberra Hospital, Canberra, Australian Capital Territory, Australia
| | - Sarah Foster
- Launceston General Hospital, Tasmanian Health Service (THS), Hobart, Tasmania, Australia
| | - Sanchia Warren
- Royal Hobart Hospital, Department of Microbiology and Infectious Diseases, Hobart, Tasmania, Australia
| | - Tony M Korman
- Monash Health, Monash Infectious Diseases, Melbourne, Victoria, Australia
| | | | - Claire Heney
- Pathology Queensland, Royal Brisbane and Women's Hospital, Brisbane, Queensland, Australia
| | | | - Morgyn Warner
- Infectious Diseases and Microbiology Department, Queen Elizabeth Hospital, Adelaide, South Australia, Australia
| | - Nicholas Wells
- South Australia Pathology, Adelaide, South Australia, Australia
| | - Desley Wilson
- South Australia Pathology, Adelaide, South Australia, Australia
| | - Hemalatha Varadhan
- Hunter New England, NSW Health Pathology, Newcastle, New South Wales, Australia
| | - Robert Stevens
- South Eastern Sydney, NSW Health Pathology, Sydney, New South Wales, Australia
- School of Biomedical Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Monica Lahra
- NSW Health Pathology, Newcastle, New South Wales, Australia
| | - Peter Newton
- Illawarra-Shoalhaven, NSW Health Pathology, Wollongong, New South Wales, Australia
| | - Michael Maley
- South Western Sydney, NSW Health Pathology, Sydney, New South Wales, Australia
- Microbiology, Liverpool Hospital, Sydney, New South Wales, Australia
| | - Sebastian van Hal
- NSW Health Pathology, Newcastle, New South Wales, Australia
- Infectious Diseases and Microbiology, Royal Prince Alfred Hospital, Sydney, New South Wales, Australia
| | - Paul R Ingram
- Department of Infectious Diseases, Fiona Stanley Hospital, Perth, Western Australia, Australia
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Delbari Y, Mohassel Y, Kakaei E, Bahrami Y. Identification and anti-bacterial property of endophytic actinobacteria from Thymes kotschyanus, Allium hooshidaryae, and Cerasus microcarpa. Sci Rep 2023; 13:13145. [PMID: 37573468 PMCID: PMC10423286 DOI: 10.1038/s41598-023-40478-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Accepted: 08/10/2023] [Indexed: 08/14/2023] Open
Abstract
The arbitrary and overuses of antibiotics have resulted in the emergence of multidrug resistance bacteria which encounters human to a serious public health problem. Thus, there is an ever-increasing demand for discovery of novel effective antibiotics with new modes of function against resistant pathogens. Endophytic actinobacteria (EA) have currently been considered as one of the most prospective group of microorganisms for discovery of therapeutic agents. This study aimed to isolate EA from Thymes kotschyanus, Allium hooshidaryae, and Cerasus microcarpa plants and to evaluate their antibacterial properties. The healthy samples were collected, dissected and surface-sterilized before cultured on four different selection media at 28 °C. Nine EA were isolated and identified based on morphological and molecular properties, and scanning electron micrograph analyses. Based on phylogenetic analysis, they were taxonomically grouped into four families Streptomycetaceae, Nocardiaceae, Micromonosporaceae, and Pseudonocardiaceae. Their branched aerial mycelia produced chains of cylindrical or cube or oval shaped spores with smooth or rough surfaces. Four strains; IKBG03, IKBG05, IKBG13, and IKBG17 had less than 98.65% sequence similarity to their closely related strains, which constitute them as novel species/strains. Besides, three strains; IKBG05, IKBG13, and IKBG18 were reported as endophytes for the first time. Preliminary antibacterial activity conducted on the all isolates revealed potent antibacterial effects against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. All isolates strongly inhibited the growth of at least one of the tested pathogens. Our results reveals that the test plants are novel sources for isolating a diverse group of rare and common actinobacteria that could produce a wide range of novel biologically active natural products with antibacterial activity which have a great potential in pharmaceutical and biotechnological applications.
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Affiliation(s)
- Yaser Delbari
- Department of Medical Biotechnology, School of Medicine, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Yaser Mohassel
- Department of Clinical Biochemistry, School of Medicine, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Elham Kakaei
- Department of Medical Biotechnology, School of Medicine, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Yadollah Bahrami
- Department of Medical Biotechnology, School of Medicine, Kermanshah University of Medical Sciences, Kermanshah, Iran.
- Medical Biology Research Center, Kermanshah University of Medical Sciences, Kermanshah, Iran.
- Department of Medical Biotechnology, School of Medicine, College of Medicine and Public Health, Flinders University, Adelaide, SA, 5042, Australia.
- Advanced Marine Biomanufacturing Laboratory, Centre for Marine Bioproducts Development, College of Medicine and Public Health, Flinders University, Adelaide, SA, 5042, Australia.
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Kashyap N, Singh SK, Yadav N, Singh VK, Kumari M, Kumar D, Shukla L, Bhardwaj N, Kumar A. Biocontrol Screening of Endophytes: Applications and Limitations. PLANTS (BASEL, SWITZERLAND) 2023; 12:2480. [PMID: 37447041 DOI: 10.3390/plants12132480] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 06/24/2023] [Accepted: 06/25/2023] [Indexed: 07/15/2023]
Abstract
The considerable loss of crop productivity each year due to plant disease or pathogen invasion during pre- or post-harvest storage conditions is one of the most severe challenges to achieving the goals of food security for the rising global population. Although chemical pesticides severally affect the food quality and health of consumers, a large population relies on them for plant disease management. But currently, endophytes have been considered one of the most suitable biocontrol agents due to better colonization and acclimatization potential. However, a very limited number of endophytes have been used commercially as biocontrol agents. Isolation of endophytes and their screening to represent potential characteristics as biocontrol agents are considered challenging by different procedures. Through a web search using the keywords "endophytes as biocontrol agents" or "biocontrol mechanism of endophytes," we have succinctly summarised the isolation strategies and different in vitro and in vivo biocontrol screening methods of endophytic biocontrol agents in the present review. In this paper, biocontrol mechanisms of endophytes and their potential application in plant disease management have also been discussed. Furthermore, the registration and regulatory mechanism of the endophytic biocontrol agents are also covered.
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Affiliation(s)
- Nikhil Kashyap
- Department of Biotechnology, Noida International University, Greater Noida 203201, India
| | - Sandeep Kumar Singh
- Division of Microbiology, ICAR-Indian Agricultural Research Institute, Pusa, New Delhi 110012, India
| | - Nisha Yadav
- Division of Agriculture Extension, ICAR-Indian Agricultural Research Institute, Pusa, New Delhi 110012, India
| | - Vipin Kumar Singh
- Department of Botany, K.S. Saket P.G. College, Ayodhya 224123, India
| | - Madhuree Kumari
- Department of Biochemistry, Indian Institute of Science, Bangalore 560012, India
| | | | - Livleen Shukla
- Division of Microbiology, ICAR-Indian Agricultural Research Institute, Pusa, New Delhi 110012, India
| | - Nikunj Bhardwaj
- Department of Zoology, Maharaj Singh College, Maa Shakumbhari University, Saharanpur 247001, India
| | - Ajay Kumar
- Department of Botany, M.V. College, Buxar 802101, India
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Kaewkla O, Suriyachadkun C, Franco CMM. Streptomyces phytophilus sp. nov., an endophytic actinobacterium with biosynthesis potential as an antibiotic producer. Int J Syst Evol Microbiol 2023; 73. [PMID: 37093715 DOI: 10.1099/ijsem.0.005834] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/25/2023] Open
Abstract
An endophytic actinobacterium, strain PIP175T, was isolated from the root sample of a native apricot tree (Pittosporum angustifolium) growing on the Bedford Park campus of Flinders University, Adelaide, South Australia. This strain is a Gram stain-positive, aerobic actinobacterium with well-developed substrate mycelia. Aerial mycelia rarely produce spores and the spore chain is spiral. Strain PIP175T showed the highest 16S rRNA gene sequence similarity to Streptomyces aculeolatus DSM 41644T (99.4 %). Other closely related phylogenetic representatives include Streptomyces synnematoformans DSM 41902T (98.3 %), Streptomyces albospinus NBRC 13846T (97.6 %), Streptomyces cacaoi subsp. cacaoi NRRL B-1220T (97.5 %) and Streptomyces ruber NBRC 14600T (97.4 %). The major cellular fatty acid of this strain was iso-C16 : 0 and the major menaquinone was MK-9(H6). The whole-cell sugar contained galactose, glucose and mannose. Chemotaxonomic data confirmed that strain PIP175T belonged to the genus Streptomyces. Digital DNA-DNA hybridization, average nucleotide identity based on blast and OrthoANIu results between strain PIP175T and S. aculeolatus DSM 41644T were 60.0, 94.1 and 94.9 %, respectively. Genotypic and phenotypic data and genome analysis results allowed the differentiation of strain PIP175T from its closest species with validly published names. Strain PIP175T showed good activity against methicillin-resistant Staphylococcus aureus 03120385. Genome mining of strain PIP175T revealed biosynthetic genes encoding proteins relating to antibiotic production, plant growth promotion and biodegradation enzymes. The name proposed for the new species is Streptomyces phytophilus sp. nov. The type strain is PIP175T (=DSM 103379T=TBRC 6026T).
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Affiliation(s)
- Onuma Kaewkla
- Department of Biology, Faculty of Science, Mahasarakham University, Maha Sarakham Province, 44150, Thailand
- Department of Medical Biotechnology, College of Medicine and Public Health, Flinders University, Bedford Park, Adelaide, 5042, Australia
| | - Chanwit Suriyachadkun
- Thailand Bioresource Research Center (TBRC), National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Klong Luang, Pathumthani 12120, Thailand
| | - Christopher Milton Mathew Franco
- Department of Medical Biotechnology, College of Medicine and Public Health, Flinders University, Bedford Park, Adelaide, 5042, Australia
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Ryabova OV, Gagarina AA. Actinomycetes as the Basis of Probiotics for Plants. APPL BIOCHEM MICRO+ 2022. [DOI: 10.1134/s0003683822070055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Diversity and Bioactivity of Endophytic Actinobacteria Associated with Grapevines. Curr Microbiol 2022; 79:390. [PMCID: PMC9633489 DOI: 10.1007/s00284-022-03068-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Accepted: 09/29/2022] [Indexed: 11/05/2022]
Abstract
AbstractGrapevine trunk diseases (GTDs) are a significant problem for New Zealand viticulture. Endophytic actinobacteria are of interest as potential biocontrol agents due to their ability to inhibit plant pathogens and improve plant growth. However, no studies have investigated the diversity of actinobacteria associated with grapevines in New Zealand vineyards and their bioactivity. Actinobacteria diversity in different ‘Sauvignon blanc’ vine tissues from three vineyards (conventional and organic management, and different vine ages) was assessed using different methods and media. Forty-six endophytic actinobacteria were isolated, with more isolates recovered from roots (n = 45) than leaves (n = 1) and shoot internodes (n = 0). More isolates were recovered from the organic (n = 21) than conventional (n = 8) vineyard, mature (25-year old; n = 21) than young (2-year old; n = 2) vines and using a tissue maceration technique (n = 40). Actinomycete Isolation Agar, International Streptomyces Project 2, and Starch Casein media were effective for actinobacteria isolation. Most of the isolates recovered belonged to Streptomyces, with one isolate identified as Mycolicibacterium. Forty isolates were assessed for antifungal activity and plant growth-promoting (PGP) characteristics. Of these, 13 isolates had antifungal activity against test GTD pathogens (Dactylonectria macrodidyma, Eutypa lata, Ilyonectria liriodendri, Neofusicoccum parvum, and N. luteum). Eighteen isolates exhibited more than one PGP trait; 25siderophore production (n = 25), phosphate solubilization (n = 6), and indole acetic acid production (n = 16). Two strains, Streptomyces sp. LUVPK-22 and Streptomyces sp. LUVPK-30, exhibited the best antifungal and PGP properties. This study revealed the diversity of culturable endophytic actinobacteria from grapevines in New Zealand vineyards and their biocontrol potential against GTD pathogens.
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Identification and antibacterial evaluation of endophytic actinobacteria from Luffa cylindrica. Sci Rep 2022; 12:18236. [PMID: 36309579 PMCID: PMC9617871 DOI: 10.1038/s41598-022-23073-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2022] [Accepted: 10/25/2022] [Indexed: 12/31/2022] Open
Abstract
The emergence of antibiotic-resistant bacteria has limited treatment options and led to the untreatable infections, thereby necessitating the discovery of new antibiotics to battel against bacteria. Natural products from endophytic actinobacteria (EA) serve as a reservoir for discovery of new antibiotics. Therefore, the current study focused on the isolation and antibacterial properties of EA isolated from Luffa cylindrica. Six strains were identified using morphological characterization, SEM analyses and 16S rRNA gene sequencing from the roots and leaves of the plant. They were taxonomically classified as Streptomycetaceae family. This is the first report on EA form L. cylindrica. The strains produced a chain of oval, cubed or cylindrical shaped spores with spiny or smooth surfaces. Three strains; KUMS-B3, KUMS-B4 and KUMS-B6 were reported as endophytes for the first time. Fifty percent of isolates were isolated from leaves samples using YECD medium. Our results showed that the sampling time and seasons may affect the bacterial diversity. All six strains had antibacterial activity against at least one of the tested bacteria S. aureus, P. aeruginosa, and E. coli. Among the strains, KUMS-B6 isolate, closely related to S. praecox, exhibited the highest antibacterial activity against both gram-positive and negative bacteria. KUMS-B6, KUMS-B5 and KUMS-B4 isolates strongly inhibited the growth of P. aeruginosa. Interestingly, the strains, isolated from leaves exhibited stronger antagonist activities compared to those isolated from the roots. The study revealed that the isolated strains from Luffa produce a plethora of bioactive substances that are potential source of new drug candidates for the treatment of infections.
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Liu JQ, Chen SM, Zhang CM, Xu MJ, Xing K, Li CG, Li K, Zhang YQ, Qin S. Abundant and diverse endophytic bacteria associated with medicinal plant Arctium lappa L. and their potential for host plant growth promoting. Antonie Van Leeuwenhoek 2022; 115:1405-1420. [DOI: 10.1007/s10482-022-01785-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Accepted: 10/11/2022] [Indexed: 10/31/2022]
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Ali AR, Bahrami Y, Kakaei E, Mohammadzadeh S, Bouk S, Jalilian N. Isolation and identification of endophytic actinobacteria from Citrullus colocynthis (L.) Schrad and their antibacterial properties. Microb Cell Fact 2022; 21:206. [PMID: 36217205 PMCID: PMC9548430 DOI: 10.1186/s12934-022-01936-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Accepted: 10/02/2022] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Antibiotic resistance poses a major threat to human health globally. Consequently, new antibiotics are desperately required to discover and develop from unexplored habitats to treat life-threatening infections. Microbial natural products (NP) are still remained as primary sources for the discovery of new antibiotics. Endophytic actinobacteria (EA) which are well-known producers of bioactive compounds could provide novel antibiotic against pathogenic bacteria. This research aimed to isolate EA from the Citrullus colocynthis plant and explore the antibacterial properties of their metabolites against pathogenic bacteria. RESULTS The healthy samples were collected, dissected and surface-sterilized before cultured on four different selection media at 28 °C. Six endophytic actinobacteria were isolated from Citrullus colocynthis plant. They were taxonomically classified into two family namely Streptomycetaceae and Nocardiopsaceae, based on colony morphological features, scanning electron microscope analysis and molecular identification of isolates. This is the first report on the identification of EA form Citrullus colocynthis and their antibacterial activity. The strains generated a chain of vibrio-comma, cubed or cylindrical shaped spores with indenting or smooth surfaces. Three of those were reported as endophytes for the first time. The strain KUMS-C1 showed 98.55% sequence similarity to its closely related strains which constitutes as a novel species/ strain for which the name Nocardiopsis colocynthis sp. was proposed for the isolated strain. Five isolated strains had antagonist activity against S. aureus, P. aeruginosa, and E. coli. Among those, stain KUMS-C6 showed the broadest spectrum of antibacterial activity against all test bacteria, whereas the strain KUMS-C4 had no antibacterial activity. CONCLUSIONS NPs have a long history of safe and efficient use for development of pharmaceutical products. Our study highlights that Citrullus colocynthis is an untapped source for the isolation of EA, generating novel and bioactive metabolites by which might lead to discovery of new antibiotic(s). This study reveals the future of new antibiotic developments looks bright against multi-drug resistance diseases by mining under- or unexplored habitats.
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Affiliation(s)
- Aram R Ali
- Department of Medical Biotechnology, School of Medicine, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Yadollah Bahrami
- Department of Medical Biotechnology, School of Medicine, Kermanshah University of Medical Sciences, Kermanshah, Iran. .,Medical Biology Research Center, Kermanshah University of Medical Sciences, Kermanshah, Iran. .,Department of Medical Biotechnology, School of Medicine, College of Medicine and Public Health, Flinders University, Adelaide, SA, 5042, Australia.
| | - Elham Kakaei
- Department of Medical Biotechnology, School of Medicine, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Sara Mohammadzadeh
- Department of Medical Biotechnology, School of Medicine, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Sasan Bouk
- Department of Medical Biotechnology, School of Medicine, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Nastaran Jalilian
- Forests and Rangelands Research Department, Kermanshah Agricultural and Natural Resources Research and Education Center, (AREEO), Kermanshah, Iran
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Dutta S, Choi SY, Lee YH. Temporal Dynamics of Endogenous Bacterial Composition in Rice Seeds During Maturation and Storage, and Spatial Dynamics of the Bacteria During Seedling Growth. Front Microbiol 2022; 13:877781. [PMID: 35935216 PMCID: PMC9355576 DOI: 10.3389/fmicb.2022.877781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Accepted: 06/10/2022] [Indexed: 11/17/2022] Open
Abstract
Seed endophytes are of interest because they are believed to affect seed quality, and ultimately, plant growth and fitness. A comprehensive understanding of the assembly of the seed microbiome during seed development and maturation, the fate of microbes during storage, and the migration of microbes during seedling growth are still lacking. In this study, to understand the assembly and fate of endogenous bacteria in rice seeds from the ripening stage to the storage and seedling stages, we employed culture-dependent and metagenomic analyses. Bacterial communities in rice seeds were composed of a few dominant taxa that were introduced at the milky and dough stages, and they persisted during seed maturation. The culturable bacterial population gradually increased during the ripening stage, whereas there was a gradual decrease during storage. Bacteria that persisted during storage proliferated after imbibition and were distributed and established in the shoots and roots of rice seedlings. The storage temperature influenced the abundance of bacteria, which consequently changed the bacterial composition in the shoots and roots of seedlings. Pantoea, Pseudomonas, and Allorhizobium were consistently abundant from seed development to the germination stage. Some endogenous bacterial strains significantly promoted the growth of Arabidopsis and rice plants. Overall, our results indicate that rice seeds are colonized by a few bacterial taxa during seed development, and their relative abundance fluctuates during storage and contributes significantly to the establishment of endophytes in the stems and roots of rice plants. The selected bacterial isolates can be used to improve the growth and health of rice plants. To the best of our knowledge, this is the first study to reveal the dynamics of bacterial populations during storage of rice seeds at different temperatures. The temporal dynamics of the bacterial community during seed storage provide clues for the manipulation of endogenous bacteria in rice plants.
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Affiliation(s)
- Swarnalee Dutta
- Division of Biotechnology, Jeonbuk National University, Jeonju, South Korea
| | - Soo Yeon Choi
- Crop Foundation Research Division, National Institute of Crop Science, Wanju-gun, South Korea
| | - Yong Hoon Lee
- Division of Biotechnology, Jeonbuk National University, Jeonju, South Korea
- Plant Medical Research Center, Advanced Institute of Environment and Bioscience, Institute of Bio-Industry, Jeonbuk National University, Jeonju, South Korea
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Kaewkla O, Sukpanoa S, Suriyachadkun C, Chamroensaksi N, Chumroenphat T, Franco CMM. Streptomyces spinosus sp. nov. and Streptomyces shenzhenensis subsp. oryzicola subsp. nov. endophytic actinobacteria isolated from Jasmine rice and their genome mining for potential as antibiotic producers and plant growth promoters. Antonie van Leeuwenhoek 2022; 115:871-888. [PMID: 35597859 DOI: 10.1007/s10482-022-01741-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Accepted: 04/15/2022] [Indexed: 11/25/2022]
Abstract
Two endophytic actinobacteria, strains SBTS01T and W18L9T, were isolated from leaf sheath and leaf tissue, respectively, of Jasmine rice (Oryza sativa KDML 105) grown in a rice paddy field in Roi Et Province, Thailand. A polyphasic taxonomic study showed that both strains belong to the genus Streptomyces; they are aerobic, forming well-developed substrate mycelia and aerial mycelia with long chains of spores. Strain SBTS01T shares high 16S rRNA gene sequence similarity with Streptomyces rochei NRRL B-2410 T (99.0%) and Streptomyces naganishii NRRL ISP-5282 T (99.0%). Strain W18L9T shares high 16S rRNA gene sequence similarity with Streptomyces shenzhenensis DSM 42034 T (99.7%). The genotypic and phenotypic properties of strains SBTS01T and W18L9T distinguish these two strains from the closely related species with validly published names. The genome analysis showed the dDDH, ANIb and ANIm values of the draft genome between strain SBTS01T and its close neighbour in the phylogenomic tree, Streptomyces corchorusii DSM 40340T to be 54.1, 92.6, and 94.3%, respectively; similarly for strain W18L9T and the closely related species S. shenzhenensis DSM 42034 T values were 72.5, 95.1 and 97.0%. The name proposed for the new species represented by the type strain SBTS01T is Streptomyces spinosus (= NRRL B-65636 T = TBRC 15052T). The name proposed for the novel subspecies of strain W18L9T is Streptomyces shenzhenensis subsp. oryzicola (= NRRL B-65635 T = TBRC 15051T). Recognition of this subspecies also permits the description of Streptomyces shenzhenensis subsp. shenzhenensis. Strains SBTS01T and W18L9T can produce antibiotic against rice and human pathogens and showed plant growth promoting properties such as production of indole acetic acid, cytokinin, 1-aminocyclopropane-1-carboxylate (ACC) deaminase, siderophores and cellulase. Genomic data mining of these two strains confirmed their potential as antibiotic producers and plant growth promoters. Their genomes contain multiple biosynthetic gene clusters including those for terpene, type 1, 2 and 3 polyketide synthase, Non-ribosomal peptide synthetase and lanthipeptides. Genes encoding plant growth promoting traits such; nitrogen fixation, ACC deaminase, siderophore production and stress-related adaption may have ecological significance.
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Affiliation(s)
- Onuma Kaewkla
- Department of Biology, Faculty of Science, Mahasarakham University, Maha Sarakham Province, 44150, Thailand.
- Department of Medical Biotechnology, College of Medicine and Public Health, Flinders University, Adelaide 5042, Australia.
| | - Sudarat Sukpanoa
- Department of Biology, Faculty of Science, Mahasarakham University, Maha Sarakham Province, 44150, Thailand
| | - Chanwit Suriyachadkun
- Thailand Bioresource Research Center (TBRC), National Science and Technology Development Agency, Klong Luang, Pathumthani, 12120, Thailand
| | - Nitcha Chamroensaksi
- National Biobank of Thailand (NBT), National Science and Technology Development Agency, Klong Luang, Pathumthani, 12120, Thailand
| | - Theeraphan Chumroenphat
- Laboratory Equipment Center, Mahasarakham University, Maha Sarakham Province, 44150, Thailand
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Anteneh YS, Yang Q, Brown MH, Franco CMM. Factors affecting the isolation and diversity of marine sponge-associated bacteria. Appl Microbiol Biotechnol 2022; 106:1729-1744. [PMID: 35103809 PMCID: PMC8882111 DOI: 10.1007/s00253-022-11791-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 01/13/2022] [Accepted: 01/17/2022] [Indexed: 12/24/2022]
Abstract
Marine sponges are an ideal source for isolating as yet undiscovered microorganisms with some sponges having about 50% of their biomass composed of microbial symbionts. This study used a variety of approaches to investigate the culturable diversity of the sponge-associated bacterial community from samples collected from the South Australian marine environment. Twelve sponge samples were selected from two sites and their bacterial population cultivated using seven different agar media at two temperatures and three oxygen levels over 3 months. These isolates were identified using microscopic, macroscopic, and 16S rRNA gene analysis. A total of 1234 bacterial colonies were isolated which consisted of four phyla: Actinobacteria, Firmicutes, Proteobacteria, and Bacteroidetes, containing 21 genera. The diversity of the bacterial population was demonstrated to be influenced by the type of isolation medium, length of the incubation period and temperature, sponge type, and oxygen level. The findings of this study showed that marine sponges of South Australia can yield considerable bacterial culturable diversity if a comprehensive isolation strategy is implemented. Two sponges, with the highest and the lowest diversity of culturable isolates, were examined using next-generation sequencing to better profile the bacterial population. A marked difference in terms of phyla and genera was observed using culture-based and culture-independent approaches. This observed variation displays the importance of utilizing both methods to reflect a more complete picture of the microbial population of marine sponges. KEY POINTS: Improved bacterial diversity due to long incubations, 2 temperatures, and 3 oxygen levels. Isolates identified by morphology, restriction digests, and 16S rRNA gene sequencing. At least 70% of culturable genera were not revealed by NGS methods.
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Affiliation(s)
- Yitayal S Anteneh
- Medical Biotechnology, College of Medicine and Public Health, Flinders University, Bedford Park, SA, 5042, Australia
- Department of Medical Microbiology, College of Medicine, Addis Ababa University, Addis Ababa, Ethiopia
- Centre for Marine Bioproducts Development, College of Medicine and Public Health, Flinders University, Bedford Park, SA, 5042, Australia
| | - Qi Yang
- Centre for Marine Bioproducts Development, College of Medicine and Public Health, Flinders University, Bedford Park, SA, 5042, Australia
- Center for Marine Drugs, State Key Laboratory of Oncogene and Related Genes, Department of Pharmacy, School of Medicine, Renji Hospital, Shanghai Jiao Tong University, Shanghai, 200127, China
| | - Melissa H Brown
- College of Science and Engineering, Flinders University, Bedford Park, SA, 5042, Australia
| | - Christopher M M Franco
- Medical Biotechnology, College of Medicine and Public Health, Flinders University, Bedford Park, SA, 5042, Australia.
- Centre for Marine Bioproducts Development, College of Medicine and Public Health, Flinders University, Bedford Park, SA, 5042, Australia.
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16
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Padilla-Gálvez N, Luengo-Uribe P, Mancilla S, Maurin A, Torres C, Ruiz P, France A, Acuña I, Urrutia H. Antagonistic activity of endophytic actinobacteria from native potatoes (Solanum tuberosum subsp. tuberosum L.) against Pectobacterium carotovorum subsp. carotovorum and Pectobacterium atrosepticum. BMC Microbiol 2021; 21:335. [PMID: 34876006 PMCID: PMC8650274 DOI: 10.1186/s12866-021-02393-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Accepted: 11/15/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The native potatoes (Solanum tuberosum subsp. tuberosum L.) grown in Chile (Chiloé) represent a new, unexplored source of endophytes to find potential biological control agents for the prevention of bacterial diseases, like blackleg and soft rot, in potato crops. RESULT The objective of this study was the selection of endophytic actinobacteria from native potatoes for antagonistic activity against Pectobacterium carotovorum subsp. carotovorum and Pectobacterium atrosepticum, and their potential to suppress tissue maceration symptoms in potato tubers. This potential was determined through the quorum quenching activity using a Chromobacterium violaceaum ATCC 12472 Wild type (WT) bioassay and its colonization behavior of the potato plant root system (S. tuberosum) by means of the Double labeling of oligonucleotide probes for fluorescence in situ hybridization (DOPE-FISH) targeting technique. The results showed that although Streptomyces sp. TP199 and Streptomyces sp. A2R31 were able to inhibit the growth of the pathogens, only the Streptomyces sp. TP199 isolate inhibited Pectobacterium sp. growth and diminished tissue maceration in tubers (p ≤ 0.05). Streptomyces sp. TP199 had metal-dependent acyl homoserine lactones (AHL) quorum quenching activity in vitro and was able to colonize the root endosphere 10 days after inoculation. CONCLUSIONS We concluded that native potatoes from southern Chile possess endophyte actinobacteria that are potential agents for the disease management of soft rot and blackleg.
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Affiliation(s)
- Natalia Padilla-Gálvez
- Laboratorio de Biopelículas y Microbiología Ambiental, Centro de Biotecnología, Universidad de Concepción, Victor Lamas 1290, P.O. Box: 160 C, Concepción, Chile
| | - Paola Luengo-Uribe
- Laboratorio de Biopelículas y Microbiología Ambiental, Centro de Biotecnología, Universidad de Concepción, Victor Lamas 1290, P.O. Box: 160 C, Concepción, Chile
| | - Sandra Mancilla
- Instituto de Investigaciones Agropecuarias, INIA Remehue. Ruta 5 Norte Km 8-, Osorno, Región de Los Lagos, Chile
| | - Amandine Maurin
- Laboratorio de Biopelículas y Microbiología Ambiental, Centro de Biotecnología, Universidad de Concepción, Victor Lamas 1290, P.O. Box: 160 C, Concepción, Chile
- University of Montpellier, Montpellier, France
| | - Claudia Torres
- Laboratorio de Biopelículas y Microbiología Ambiental, Centro de Biotecnología, Universidad de Concepción, Victor Lamas 1290, P.O. Box: 160 C, Concepción, Chile
| | - Pamela Ruiz
- Laboratorio de Biopelículas y Microbiología Ambiental, Centro de Biotecnología, Universidad de Concepción, Victor Lamas 1290, P.O. Box: 160 C, Concepción, Chile
- Departamento de Ciencias Biológicas, Facultad de Ciencias de la Vida, Universidad Andres Bello, Autopista Concepción Talcahuano # 7100, 4300866, Talcahuano, Chile
| | - Andrés France
- Instituto de Investigaciones Agropecuarias, INIA Quilamapu, Región de Ñuble, Chillán, Chile
| | - Ivette Acuña
- Instituto de Investigaciones Agropecuarias, INIA Remehue. Ruta 5 Norte Km 8-, Osorno, Región de Los Lagos, Chile
| | - Homero Urrutia
- Laboratorio de Biopelículas y Microbiología Ambiental, Centro de Biotecnología, Universidad de Concepción, Victor Lamas 1290, P.O. Box: 160 C, Concepción, Chile.
- Departamento de Microbiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile.
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Wu YR, Li CB, Wu YH, Li L, Li B, Li WB, Ma BJ, Yan ZY. Diversity and function of culturable actinobacteria in the root-associated of Salvia miltiorrhiza Bunge. PeerJ 2021; 9:e11749. [PMID: 34285837 PMCID: PMC8274492 DOI: 10.7717/peerj.11749] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Accepted: 06/19/2021] [Indexed: 01/15/2023] Open
Abstract
The root-associated actinobacteria play important roles in plant growth, nutrient use, and disease resistance due to their functional diversity. Salvia miltiorrhiza is a critical medicinal plant in China. The root actinobacterial community structure has been studied; however, the functions of root-associated actinobacteria of S. miltiorrhiza have not been elucidated. This study aimed to decipher the diversity and function of the culturable root-associated actinobacteria in plant growth using culture-dependent technology and culturable microbe metagenomes. We isolated 369 strains from the root-associated actinobacteria, belonging to four genera, among which Streptomyces was dominant. Besides, the functional prediction revealed some pathways related to plant growth, nitrogen and phosphorus metabolism, and antagonistic pathogens. We systematically described the diversity and functions of the culturable root-associated actinobacteria community. Our results demonstrated that the culturable root-associated actinobacteria of S. miltiorrhiza have rich functionalities, explaining the possible contribution of culturable root-associated actinobacteria to S. miltiorrhiza's growth and development. This study provides new insights into understanding the function of the culturable root-associated actinobacteria and can be used as a knowledge base for plant growth promoters and biological control agent development in agriculture.
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Affiliation(s)
- Yu-Rui Wu
- School of Pharmacy, Chengdu University of Traditional Chinese Medicine, State Key Laboratory of Characteristic Chinese Medicine Resources in Southwest China, Chengdu, China
| | - Cui-Bai Li
- School of Pharmacy, Chengdu University of Traditional Chinese Medicine, State Key Laboratory of Characteristic Chinese Medicine Resources in Southwest China, Chengdu, China
| | - Yan-Hong Wu
- School of Pharmacy, Chengdu University of Traditional Chinese Medicine, State Key Laboratory of Characteristic Chinese Medicine Resources in Southwest China, Chengdu, China
| | - Lan Li
- School of Pharmacy, Chengdu University of Traditional Chinese Medicine, State Key Laboratory of Characteristic Chinese Medicine Resources in Southwest China, Chengdu, China
| | - Bo Li
- School of Pharmacy, Chengdu University of Traditional Chinese Medicine, State Key Laboratory of Characteristic Chinese Medicine Resources in Southwest China, Chengdu, China
| | - Wen-Bo Li
- School of Pharmacy, Chengdu University of Traditional Chinese Medicine, State Key Laboratory of Characteristic Chinese Medicine Resources in Southwest China, Chengdu, China
| | - Bu-Jin Ma
- School of Pharmacy, Chengdu University of Traditional Chinese Medicine, State Key Laboratory of Characteristic Chinese Medicine Resources in Southwest China, Chengdu, China
| | - Zhu-Yun Yan
- School of Pharmacy, Chengdu University of Traditional Chinese Medicine, State Key Laboratory of Characteristic Chinese Medicine Resources in Southwest China, Chengdu, China
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Isolation, Characterization, and Efficacy of Actinobacteria Associated with Arbuscular Mycorrhizal Spores in Promoting Plant Growth of Chili ( Capsicum flutescens L.). Microorganisms 2021; 9:microorganisms9061274. [PMID: 34207987 PMCID: PMC8230694 DOI: 10.3390/microorganisms9061274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 06/03/2021] [Accepted: 06/09/2021] [Indexed: 12/02/2022] Open
Abstract
Nowadays, microorganisms that display plant growth promoting properties are significantly interesting for their potential role in reducing the use of chemical fertilizers. This research study proposed the isolation of the actinobacteria associated with arbuscular mycorrhizal fungi (AMF) spores and the investigation of their plant growth promoting properties in the in vitro assay. Three actinobacterial strains were obtained and identified to the genus Streptomyces (GETU-1 and GIG-1) and Amycolatopsis (GLM-2). The results indicated that all actinobacterial strains produced indole-3-acetic acid (IAA) and were positive in terms of siderophore, endoglucanase, and ammonia productions. In the in vitro assay, all strains were grown in the presence of water activity within a range of 0.897 to 0.998, pH values within a range of 5–11, and in the presence of 2.5% NaCl for the investigation of drought, pH, and salt tolerances, respectively. Additionally, all strains were able to tolerate commercial insecticides (propargite and methomyl) and fungicides (captan) at the recommended dosages for field applications. Only, Amycolatopsis sp. GLM-2 showed tolerance to benomyl at the recommended dose. All the obtained actinobacteria were characterized as plant growth promoting strains by improving the growth of chili plants (Capsicum flutescens L.). Moreover, the co-inoculation treatment of the obtained actinobacteria and AMF (Claroideoglomus etunicatum) spores could significantly increase plant growth, contribute to the chlorophyll index, and enhance fruit production in chili plants. Additionally, the highest value of AMF spore production and the greatest percentage of root colonization were observed in the treatment that had been co-inoculated with Streptomyces sp. GETU-1.
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Pseudonocardia pini sp. nov., an endophytic actinobacterium isolated from roots of the pine tree Callitris preissii. Arch Microbiol 2021; 203:3407-3413. [PMID: 33890128 DOI: 10.1007/s00203-021-02309-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2021] [Revised: 03/10/2021] [Accepted: 03/26/2021] [Indexed: 10/21/2022]
Abstract
A Gram-positive, aerobic, actinobacterial strain with rod-shaped spores, CAP47RT, which was isolated from the surface-sterilized root of a native pine tree (Callitris preissii), grown in South Australia is described. The major cellular fatty acid of this strain was iso-H-C16:1 and major menaquinone was MK-8(H4). The diagnostic diamino acid in the cell-wall peptidoglycan was identified as meso-diaminopimelic acid. These chemotaxonomic data confirmed the affiliation of strain CAP47RT to the genus Pseudonocardia. Phylogenetic evaluation based on 16S rRNA gene sequence analysis placed this strain in the family Pseudonocardiaceae, being most closely related to Pseudonocardia xishanensis JCM 17906T (98.8%), Pseudonocardia oroxyli DSM 44984T (98.7%), Pseudonocardia thailandensis CMU-NKS-70T (98.7%), and Pseudonocardia ailaonensis DSM 44979T (97.9%). The results of the polyphasic study which contain genome comparisons of ANIb, ANIm, and digital DNA-DNA hybridization revealed the differentiation of strain CAP47RT from the closest species with validated names. This strain represents a novel species and the name proposed for this microorganism is Pseudonocardia pini sp. nov., indicating the source of this actinobacterium from a pine tree. The type strain is CAP47RT (= DSM 108967T = NRRL B-65534T). Genome mining revealed that this strain contained a variety of genes encoding enzymes that can degrade hazardous chemicals.
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Kaewkla O, Suriyachadkun C, Franco CMM. Streptomyces adelaidensis sp. nov., an actinobacterium isolated from the root of Callitris preissii with potential for plant growth-promoting properties. Arch Microbiol 2021; 203:3341-3352. [PMID: 33871674 DOI: 10.1007/s00203-021-02308-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2020] [Revised: 03/09/2021] [Accepted: 03/26/2021] [Indexed: 11/26/2022]
Abstract
An endophytic actinobacterium, strain CAP261T was isolated from the surface sterilized root of Callitris preissii (Australian native pine tree). As a result of a polyphasic taxonomy study, this strain was identified as a member of the genus Streptomyces. This strain was an aerobic actinobacterium with well-developed substrate mycelia with loop spore chains and the spore surfaces are verrucose. The closest phylogenetic members which shared the highest 16S rRNA gene sequences similarity was Streptomyces bottropensis ATCC 25435 T at 98.1%. Chemotaxonomic data including cell wall components, major menaquinones, and major fatty acids confirmed the affiliation of strain CAP261T to the genus Streptomyces. The results of the phylogenetic analysis, including physiological and biochemical studies in combination with genome comparison study, allowed the genotypic and phenotypic differentiation of strain CAP261T and the closest species with validly published names. ANIb, ANIm and dDDH values of strain CAP261T and S. bottropensis ATCC 25435 T were 86.7%, 89.2% and 33.9%, respectively. The name proposed for the new species is Streptomyces adelaidensis sp. nov. The type strain is CAP261T (= DSM 42026 T = NRRL B-24814 T).
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Affiliation(s)
- Onuma Kaewkla
- Department of Biology, Faculty of Science, Mahasarakham University, Maha Sarakham Province, 44150, Thailand.
- Department of Medical Biotechnology, College of Medicine and Public Health, Flinders University, Adelaide, Australia.
| | - Chanwit Suriyachadkun
- Thailand Bioresource Research Center (TBRC), National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Klong Luang, Pathumthani, 12120, Thailand
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Kaewkla O, Suriyachadkun C, Franco CMM. Micromonospora veneta sp. nov., an endophytic actinobacterium with potential for nitrogen fixation and for bioremediation. Arch Microbiol 2021; 203:2853-2861. [PMID: 33754164 DOI: 10.1007/s00203-021-02260-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2020] [Revised: 02/03/2021] [Accepted: 02/22/2021] [Indexed: 11/26/2022]
Abstract
Strain CAP181T, an endophytic actinobacterium, was isolated from a surface sterilized root sample of a native pine tree, Flinders University, Adelaide, South Australia. Chemotaxonomic data including cell wall components, major fatty acids, and major menaquinones confirmed the affiliation of strain CAP181T to the genus Micromonospora. This strain was Gram stain positive with well-developed substrate mycelia to form a single spore with hairy surface. The phylogenetic tree showed that M. coerulea NBRC 13504 T is the closest phylogenetic neighbour, sharing 99.2% 16S rRNA gene similarity and the next closest neighbor is M. chaiyaphumensis DSM 45246 T (98.7%). Genome mining of this strain revealed genes encoding to enzymes relating to nitrogen fixation and bioremediation. Based on genotypic and phenotypic studies including DNA-DNA hybridization data, strain CAP181T was different from any of the closely related species with valid names. The name proposed for the new species is Micromonospora veneta sp. nov. The type strain is CAP181T (= DSM 109713 T = NRRL B-65535 T).
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Affiliation(s)
- Onuma Kaewkla
- Department of Biology, Faculty of Science, Mahasarakham University, Kantaravichai, Maha Sarakham Province, 44150, Thailand.
- Department of Medical Biotechnology, College of Medicine and Public Health, Flinders University, Bedford park, Adelaide, 5042, Australia.
| | - Chanwit Suriyachadkun
- Thailand Bioresource Research Center (TBRC), National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Klong Luang, Pathumthani, 12120, Thailand
| | - Christopher Milton Mathew Franco
- Department of Medical Biotechnology, College of Medicine and Public Health, Flinders University, Bedford park, Adelaide, 5042, Australia
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Genome mining and description of Streptomyces albidus sp. nov., an endophytic actinobacterium with antibacterial potential. Antonie van Leeuwenhoek 2021; 114:539-551. [PMID: 33661469 DOI: 10.1007/s10482-021-01539-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Accepted: 02/08/2021] [Indexed: 10/22/2022]
Abstract
An endophytic actinobacterium, strain CAP215T was isolated from the root sample of a native pine tree (Callitris preissii), Adelaide, South Australia. This strain was a Gram stain-positive, aerobic actinobacterium with well-developed substrate mycelia. It produced spiral chains of spores. The closest phylogenetic members which shared the highest 16S rRNA gene sequence similarity were Streptomyces marinus DSM 41968T, Streptomyces haliclonae DSM 41970T and Streptomyces karpasiensis K413T at 98.2%, 98.0% and 97.9%, respectively. The major cellular fatty acid of this strain was anteiso-C15:0 and major menaquinone was MK-9(H4). Polar lipids of strain CAP215T contained diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol, phosphatidylinositol dimannoside and two unknown glycolipids. Chemotaxonomic data confirmed strain CAP215T belonged to the genus Streptomyces. Genome of strain CAP215T was 6.65 Mb with 69.8% DNA G + C content and contains 5992 coding sequences (CDS). Biosynthesis Genes Clusters (BGCs) comprised post-translationally modified peptides (RiPPs) cluster, genes encoding enzyme relating to antibiotic production; actinorhodin, surfactin and tetracenomycin. Genome mining of this strain identified genes encoding proteins relating to plant growth promotion such as pyrophosphatase, ectoine synthase, superoxide dismutase and siderophore production; penibactin and desferrioxamine E. Genes encoding beneficial enzymes; amylase, β-xylosidase, chitinase, lipase and protease were detected. The genome of this strain contained genes encoding enzymes degrading xenobiotic compounds such as 2,4-dichlorophenol 6-monooxygenase, nitroreductase and epoxide hydrolase. Also, genes encoding squalene, hopene and betacarotenoid production were observed. Digital DNA-DNA (dDDH) hybridization, Average Nucleotide Identity BLAST (ANIb), ANI-MUMmer (ANIm) between strain CAP215T and S. marinus DSM 41968T were 25.4 %, 82% and 86.4%, respectively. The data on the genotypic and phenotypic characteristics and genome analysis recognized the differentiation of strain CAP215T with the closest species with valid names. The name Streptomyces albidus sp. nov. was proposed for which the type strain is CAP215T (= DSM 42025T = NRRL B-24815T).
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Kaewkla O, Franco CMM. Amycolatopsis pittospori sp. nov., an endophytic actinobacterium isolated from native apricot tree and genome mining revealed the biosynthesis potential as antibiotic producer and plant growth promoter. Antonie Van Leeuwenhoek 2021; 114:365-377. [PMID: 33598876 DOI: 10.1007/s10482-021-01519-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2020] [Accepted: 01/17/2021] [Indexed: 11/26/2022]
Abstract
An endophytic actinobacterium, strain PIP199T, was isolated from a root sample of a native apricot growing on the Bedford Park campus of Flinders University, Adelaide, South Australia. The result of a polyphasic study showed that this strain was identified as a new member of the genus Amycolatopsis. Strain PIP199T is an aerobic actinobacterium with well-developed substrate mycelia and aerial mycelia that form short chains of spores. Amycolatopsis keratiniphila subsp. keratiniphila DSM 44409T (99.7%), Amycolatopsis lurida DSM 43134T (99.6%) and Amycolatopsis keratiniphila subsp. nogabecina DSM 44586T (99.4%) shared the highest 16S rRNA gene sequence similarity. A. keratiniphila subsp. keratiniphila DSM 44409T and A. lurida DSM 43134T were the closest phylogenetic neighbors. Chemotaxonomic data including major fatty acids, cell wall components and major menaquinones confirmed the affiliation of strain PIP199T to the genus Amycolatopsis. The phylogenetic analysis, physiological and biochemical studies and genomic study, allowed the genotypic and phenotypic differentiation of strain PIP199T and the closely related species with valid names. ANIb and dDDH values when compared to Amycolatopsis keratiniphila subsp. keratiniphila DSM 44409T were 87.3% and 36.4%, respectively. The name proposed for the new species is Amycolatopsis pittospori sp. nov. The type strain is PIP199T (= NRRL B-65536T = TBRC 10618T).
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Affiliation(s)
- Onuma Kaewkla
- Department of Biology, Faculty of Science, Mahasarakham University, Kantaravichai, Maha Sarakham Province, 44150, Thailand.
- Medical Biotechnology, College of Medicine and Public Health, Flinders University, Bedford Park, SA, 5042, Australia.
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Anteneh YS, Yang Q, Brown MH, Franco CMM. Antimicrobial Activities of Marine Sponge-Associated Bacteria. Microorganisms 2021; 9:171. [PMID: 33466936 PMCID: PMC7830929 DOI: 10.3390/microorganisms9010171] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Accepted: 01/11/2021] [Indexed: 11/17/2022] Open
Abstract
The misuse and overuse of antibiotics have led to the emergence of multidrug-resistant microorganisms, which decreases the chance of treating those infected with existing antibiotics. This resistance calls for the search of new antimicrobials from prolific producers of novel natural products including marine sponges. Many of the novel active compounds reported from sponges have originated from their microbial symbionts. Therefore, this study aims to screen for bioactive metabolites from bacteria isolated from sponges. Twelve sponge samples were collected from South Australian marine environments and grown on seven isolation media under four incubation conditions; a total of 1234 bacterial isolates were obtained. Of these, 169 bacteria were tested in media optimized for production of antimicrobial metabolites and screened against eleven human pathogens. Seventy bacteria were found to be active against at least one test bacterial or fungal pathogen, while 37% of the tested bacteria showed activity against Staphylococcus aureus including methicillin-resistant strains and antifungal activity was produced by 21% the isolates. A potential novel active compound was purified possessing inhibitory activity against S. aureus. Using 16S rRNA, the strain was identified as Streptomyces sp. Our study highlights that the marine sponges of South Australia are a rich source of abundant and diverse bacteria producing metabolites with antimicrobial activities against human pathogenic bacteria and fungi.
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Affiliation(s)
- Yitayal S. Anteneh
- College of Medicine and Public Health, Flinders University, Bedford Park, SA 5042, Australia;
- Department of Medical Microbiology, College of Medicine, Addis Ababa University, Addis Ababa 9086, Ethiopia
| | - Qi Yang
- Center for Marine Drugs, State Key Laboratory of Oncogene and Related Genes, Department of Pharmacy, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, China;
- Centre for Marine Bioproducts Development, College of Medicine and Public Health, Flinders University, Bedford Park, SA 5042, Australia
| | - Melissa H. Brown
- College of Science and Engineering, Flinders University, Bedford Park, SA 5042, Australia;
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Molina-Menor E, Gimeno-Valero H, Pascual J, Peretó J, Porcar M. High Culturable Bacterial Diversity From a European Desert: The Tabernas Desert. Front Microbiol 2021; 11:583120. [PMID: 33488536 PMCID: PMC7821382 DOI: 10.3389/fmicb.2020.583120] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Accepted: 11/27/2020] [Indexed: 12/14/2022] Open
Abstract
One of the most diverse ecological niches for microbial bioprospecting is soil, including that of drylands. Drylands are one of the most abundant biomes on Earth, but extreme cases, such as deserts, are considered very rare in Europe. The so-called Tabernas Desert is one of the few examples of a desert area in continental Europe, and although some microbial studies have been performed on this region, a comprehensive strategy to maximize the isolation of environmental bacteria has not been conducted to date. We report here a culturomics approach to study the bacterial diversity of this dryland by using a simple strategy consisting of combining different media, using serial dilutions of the nutrients, and using extended incubation times. With this strategy, we were able to set a large (254 strains) collection of bacteria, the majority of which (93%) were identified through 16S ribosomal RNA (rRNA) gene amplification and sequencing. A significant fraction of the collection consisted of Actinobacteria and Proteobacteria, as well as Firmicutes strains. Among the 254 isolates, 37 different genera were represented, and a high number of possible new taxa were identified (31%), of which, three new Kineococcus species. Moreover, 5 out of the 13 genera represented by one isolate were also possible new species. Specifically, the sequences of 80 isolates held a percentage of identity below the 98.7% threshold considered for potentially new species. These strains belonged to 20 genera. Our results reveal a clear link between medium dilution and isolation of new species, highlight the unexploited bacterial biodiversity of the Tabernas Desert, and evidence the potential of simple strategies to yield surprisingly large numbers of diverse, previously unreported, bacterial strains and species.
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Affiliation(s)
- Esther Molina-Menor
- Institute for Integrative Systems Biology I2SysBio (University of València-CSIC), Paterna, Spain
| | - Helena Gimeno-Valero
- Darwin Bioprospecting Excellence S.L., Parc Científic Universitat de València, Paterna, Spain
| | - Javier Pascual
- Darwin Bioprospecting Excellence S.L., Parc Científic Universitat de València, Paterna, Spain
| | - Juli Peretó
- Institute for Integrative Systems Biology I2SysBio (University of València-CSIC), Paterna, Spain.,Darwin Bioprospecting Excellence S.L., Parc Científic Universitat de València, Paterna, Spain.,Departament de Bioquímica i Biologia Molecular, Universitat de València, Burjassot, Spain
| | - Manuel Porcar
- Institute for Integrative Systems Biology I2SysBio (University of València-CSIC), Paterna, Spain.,Darwin Bioprospecting Excellence S.L., Parc Científic Universitat de València, Paterna, Spain
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26
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Kaewkla O, Koomsiri W, Thamchaipenet A, Franco CMM. Microbispora clausenae sp. nov., an endophytic actinobacterium isolated from the surface-sterilized stem of a Thai medicinal plant, Clausena excavala Burm. f. Int J Syst Evol Microbiol 2020; 70:6213-6219. [PMID: 33095132 PMCID: PMC8049491 DOI: 10.1099/ijsem.0.004518] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 09/26/2020] [Indexed: 11/18/2022] Open
Abstract
An endophytic actinobacterium, strain CLES2T, was discovered from the surface-sterilized stem of a Thai medicinal plant, Clausena excavala Burm. f., collected from the Phujong-Nayoa National Park, Ubon Ratchathani Province, Thailand. The results of a polyphasic taxonomic study identified this strain as a member of the genus Microbispora and a Gram-stain-positive, aerobic actinobacterium. It had well-developed substrate mycelia, which were non-motile and possessed paired spores. A phylogenetic evaluation based on 16S rRNA gene sequence analysis placed this strain in the family Streptosporangiaceae, being most closely related to Microbispora bryophytorum NEAU-TX2-2T (99.4 %), Microbispora camponoti 2C-HV3T (99.2 %), Microbispora catharanthi CR1-09T (99.2 %) and Microbispora amethystogenes JCM 3021T and Microbispora fusca NEAU-HEGS1-5T (both at 99.1 %). The major cellular fatty acid of this strain was iso-C16 : 0 and major menaquinone was MK-9(H4). The polar lipid profile of strain CLES2T contained diphosphatidylglycerol, phosphatidylmethylethanolamine, phosphatidylinositol and phosphatidylinositol dimannosides. These chemotaxonomic data confirmed the affiliation of strain CLES2T to the genus Microbispora. The DNA G+C content of this strain was 70 mol%. Digital DNA-DNA hybridization and average nucleotide identity blast values between strain CLES2T and M. catharanthi CR1-09T were 62.4 and 94.0 %, respectively. The results of the polyphasic study allowed the genotypic and phenotypic differentiation of strain CLES2T from its closest species with valid names. The name proposed for the new species is Microbispora clausenae sp. nov. The type strain is CLES2T (=DSM 101759T=NRRL B-65340T).
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Affiliation(s)
- Onuma Kaewkla
- Department of Biology, Faculty of Science, Mahasarakham University, Maha Sarakham 44150, Thailand
- Department of Medical Biotechnology, College of Medicine and Public Health, Flinders University, Bedford Park, SA 5042, Australia
| | - Wilaiwan Koomsiri
- Department of Genetics, Kasetsart University, Chatuchuk, Bangkok 10900, Thailand
- Omics Center for Agriculture, Bioresources, Food and Health, Kasetsart University (OmiKU), Bangkok 10900, Thailand
| | - Arinthip Thamchaipenet
- Omics Center for Agriculture, Bioresources, Food and Health, Kasetsart University (OmiKU), Bangkok 10900, Thailand
- Department of Genetics, Kasetsart University, Chatuchak, Bangkok 10900, Thailand
| | - Christopher Milton Mathew Franco
- Department of Medical Biotechnology, College of Medicine and Public Health, Flinders University, Bedford Park, SA 5042, Australia
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Ayswaria R, Vasu V, Krishna R. Diverse endophytic Streptomyces species with dynamic metabolites and their meritorious applications: a critical review. Crit Rev Microbiol 2020; 46:750-758. [PMID: 33044894 DOI: 10.1080/1040841x.2020.1828816] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
The strains of actinobacteria are unique as they lie between true fungi and bacteria and several of them were reported as endophytic actinobacteria as they were isolated from the inner regions of various plant parts and will enhance uptake of nutrients and improve defense against pathogens. Literature and scientific communications reported the relationship between the endophytes and plants, most of them concluded the association as commensalism. Remarkably, bioactive compounds from endophytic Streptomyces sp. were confirmed with various applications. A retrospective consolidation on the endophytic Streptomyces sp. and their metabolite application in day to day life is presented here. It was deduced that this group of the organism are a source for a wide range of bioactive compounds including anticancer agents, immune suppressor, plant growth promoters, anti-inflammatory agents, anti-tumor agents, enzymes and antimicrobial substances. These antimicrobial metabolites show broad-spectrum activity and are effective against bacteria and fungi. The mechanism of action of secondary metabolites from endophytes and its positive influence on the host plants are noted as involvement in deterrence, antifeedant activity, toxicity against common pests, and as enhancers for physical mechanisms such as water uptake and sunlight absorption, thus supporting the growth of host plants.
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Affiliation(s)
- Reshma Ayswaria
- Microboilte Research Development Private Limited, Manipal-Gok Bioincubator, MAHE Advanced Research Center, Manipal, Karnataka, India
| | - Vineeth Vasu
- Microboilte Research Development Private Limited, Manipal-Gok Bioincubator, MAHE Advanced Research Center, Manipal, Karnataka, India
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Papik J, Folkmanova M, Polivkova-Majorova M, Suman J, Uhlik O. The invisible life inside plants: Deciphering the riddles of endophytic bacterial diversity. Biotechnol Adv 2020; 44:107614. [PMID: 32858117 DOI: 10.1016/j.biotechadv.2020.107614] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 07/14/2020] [Accepted: 08/15/2020] [Indexed: 10/25/2022]
Abstract
Endophytic bacteria often promote plant growth and protect their host plant against pathogens, herbivores, and abiotic stresses including drought, increased salinity or pollution. Current agricultural practices are being challenged in terms of climate change and the ever-increasing demand for food. Therefore, the rational exploitation of bacterial endophytes to increase the productivity and resistance of crops appears to be very promising. However, the efficient and larger-scale use of bacterial endophytes for more effective and sustainable agriculture is hindered by very little knowledge on molecular aspects of plant-endophyte interactions and mechanisms driving bacterial communities in planta. In addition, since most of the information on bacterial endophytes has been obtained through culture-dependent techniques, endophytic bacterial diversity and its full biotechnological potential still remain highly unexplored. In this study, we discuss the diversity and role of endophytic populations as well as complex interactions that the endophytes have with the plant and vice versa, including the interactions leading to plant colonization. A description of biotic and abiotic factors influencing endophytic bacterial communities is provided, along with a summary of different methodologies suitable for determining the diversity of bacterial endophytes, mechanisms governing the assembly and structure of bacterial communities in the endosphere, and potential biotechnological applications of endophytes in the future.
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Affiliation(s)
- Jakub Papik
- University of Chemistry and Technology, Prague, Faculty of Food and Biochemical Technology, Department of Biochemistry and Microbiology, Prague, Czech Republic
| | - Magdalena Folkmanova
- University of Chemistry and Technology, Prague, Faculty of Food and Biochemical Technology, Department of Biochemistry and Microbiology, Prague, Czech Republic
| | - Marketa Polivkova-Majorova
- University of Chemistry and Technology, Prague, Faculty of Food and Biochemical Technology, Department of Biochemistry and Microbiology, Prague, Czech Republic
| | - Jachym Suman
- University of Chemistry and Technology, Prague, Faculty of Food and Biochemical Technology, Department of Biochemistry and Microbiology, Prague, Czech Republic
| | - Ondrej Uhlik
- University of Chemistry and Technology, Prague, Faculty of Food and Biochemical Technology, Department of Biochemistry and Microbiology, Prague, Czech Republic.
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29
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Musa Z, Ma J, Egamberdieva D, Abdelshafy Mohamad OA, Abaydulla G, Liu Y, Li WJ, Li L. Diversity and Antimicrobial Potential of Cultivable Endophytic Actinobacteria Associated With the Medicinal Plant Thymus roseus. Front Microbiol 2020; 11:191. [PMID: 32226412 PMCID: PMC7080825 DOI: 10.3389/fmicb.2020.00191] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Accepted: 01/27/2020] [Indexed: 11/30/2022] Open
Abstract
We report for the first time the isolation of endophytic actinobacteria associated with wild populations of the Chinese medicinal herb Thymus roseus Schipcz obtained from the arid land in Ili and Tacheng of the Xinjiang Province, China. Strains were isolated by special pretreatment of plant tissues and identified based on their 16S rRNA gene sequences, and their antimicrobial activities in vitro were evaluated. A total of 126 endophytic actinobacteria belonging to two classes, eight orders, 14 families, and 24 genera were isolated from different organs at the Ili and Tacheng sites. In addition, the diversity of culturable endophytic actinobacteria genera was higher at Tacheng site (n = 71, 56.35%) than the Ili site (n = 55, 43.65%). A neighbor-joining tree of 126 isolated actinobacteria showing the phylogenetic relationships based on 16S rRNA gene sequences and the genus Streptomyces was the most dominant isolate. The number of endophytic actinobacteria genera obtained from root tissues (n = 54, 42.86%) was higher compared to stem (n = 35, 27.78%) and leaf tissue (n = 37, 29.36%). Among 126 endophytic actinobacteria, 54 strains were antagonistic against at least one or more indicator organisms in vitro. Notably, most strains of Streptomyces proved antagonistic activities. For example, strain T4SB028, namely Streptomyces polyantibioticus, showed the highest inhibition ratio reached 67.06, 64.20, and 70.55% against Alternaria solani, Valsa malicola, and Valsa mali, respectively. The results demonstrate that about 30.95%, 23.01% of the tested endophytic actinobacteria were capable of producing siderophores and chitinase, respectively. Additionally, the results of the amplification of biosynthetic genes polyketide synthetase (PKS-I) and non-ribosomal peptide synthetase (NRPS) indicated that at least one antibiotic biosynthetic gene was detected in 27 (50%) of the tested strains. Our result emphasizes that the endophytic actinobacteria communities are different based on the plant tissues and the geographical environment of the sampled area. Thus, we conclude that T. roseus Schipcz. provided a rich source of endophytic actinobacteria that exhibited a broad-spectrum antimicrobial agent.
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Affiliation(s)
- Zulpiya Musa
- CAS Key Laboratory of Biogeography and Bioresource in Arid Land, Xinjiang Institute of Ecology and Geography, Ürümqi, China.,Department of Medicine, College of Kashgar Vocational Technology, Kashgar, China
| | - Jinbiao Ma
- CAS Key Laboratory of Biogeography and Bioresource in Arid Land, Xinjiang Institute of Ecology and Geography, Ürümqi, China
| | - Dilfuza Egamberdieva
- CAS Key Laboratory of Biogeography and Bioresource in Arid Land, Xinjiang Institute of Ecology and Geography, Ürümqi, China.,Faculty of Biology, National University of Uzbekistan, Tashkent, Uzbekistan
| | - Osama Abdalla Abdelshafy Mohamad
- CAS Key Laboratory of Biogeography and Bioresource in Arid Land, Xinjiang Institute of Ecology and Geography, Ürümqi, China.,Department of Environmental Protection, Faculty of Environmental Agricultural Sciences, Arish University, Arish, Egypt
| | - Gulsumay Abaydulla
- Xinjiang Laboratory of Resources Microbiology, College of Life Sciences and Technology, Xinjiang University, Ürümqi, China
| | - Yonghong Liu
- CAS Key Laboratory of Biogeography and Bioresource in Arid Land, Xinjiang Institute of Ecology and Geography, Ürümqi, China
| | - Wen-Jun Li
- CAS Key Laboratory of Biogeography and Bioresource in Arid Land, Xinjiang Institute of Ecology and Geography, Ürümqi, China.,State Key Laboratory of Biocontrol and Guangdong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Li Li
- CAS Key Laboratory of Biogeography and Bioresource in Arid Land, Xinjiang Institute of Ecology and Geography, Ürümqi, China
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30
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Yadav AN, Singh J, Rastegari AA, Yadav N. Phyllospheric Microbiomes: Diversity, Ecological Significance, and Biotechnological Applications. ACTA ACUST UNITED AC 2020. [PMCID: PMC7123684 DOI: 10.1007/978-3-030-38453-1_5] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The phyllosphere referred to the total aerial plant surfaces (above-ground portions), as habitat for microorganisms. Microorganisms establish compositionally complex communities on the leaf surface. The microbiome of phyllosphere is rich in diversity of bacteria, fungi, actinomycetes, cyanobacteria, and viruses. The diversity, dispersal, and community development on the leaf surface are based on the physiochemistry, environment, and also the immunity of the host plant. A colonization process is an important event where both the microbe and the host plant have been benefited. Microbes commonly established either epiphytic or endophytic mode of life cycle on phyllosphere environment, which helps the host plant and functional communication with the surrounding environment. To the scientific advancement, several molecular techniques like metagenomics and metaproteomics have been used to study and understand the physiology and functional relationship of microbes to the host and its environment. Based on the available information, this chapter describes the basic understanding of microbiome in leaf structure and physiology, microbial interactions, especially bacteria, fungi, and actinomycetes, and their adaptation in the phyllosphere environment. Further, the detailed information related to the importance of the microbiome in phyllosphere to the host plant and their environment has been analyzed. Besides, biopotentials of the phyllosphere microbiome have been reviewed.
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Affiliation(s)
- Ajar Nath Yadav
- Department of Biotechnology, Eternal University, Baru Sahib, Himachal Pradesh India
| | - Joginder Singh
- Department of Microbiology, Lovely Professional University, Phagwara, Punjab India
| | | | - Neelam Yadav
- Gopi Nath PG College, Veer Bahadur Singh Purvanchal University, Ghazipur, Uttar Pradesh India
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31
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Wang Z, Yu Z, Zhao J, Zhuang X, Cao P, Guo X, Liu C, Xiang W. Community Composition, Antifungal Activity and Chemical Analyses of Ant-Derived Actinobacteria. Front Microbiol 2020; 11:201. [PMID: 32117188 PMCID: PMC7026373 DOI: 10.3389/fmicb.2020.00201] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Accepted: 01/28/2020] [Indexed: 12/13/2022] Open
Abstract
Actinobacteria associated with insects represent one potentially rich source of novel natural products with antifungal activity. Here, we investigated the phylogenetic diversity and community composition of actinobacteria associated with ants using a combination of culture-dependent and -independent methods. Further, we assessed the antagonistic activity against phytopathogenic fungi and identified the secondary metabolites from isolates with bioactivity. A total of 416 actinobacterial isolates were obtained from three ant species (Camponotus japonicus, Lasius fuliginosus, and Lasius flavus) located in five nests. The largest amount of isolates were observed in the head samples. 16S rRNA gene sequencing showed that the isolates were diverse and belonged to ten genera within the phylum Actinobacteria, with Streptomyces and Micromonospora comprising the most abundant genera. High-throughput sequencing analyses revealed that the actinobacterial communities were more diverse and dominated by the families Nocardioidaceae, Nocardiaceae, Dermacoccaceae, Intrasporangiaceae, and Streptomycetaceae. In addition, 52.3% of the representative isolates had inhibitory properties against phytopathogenic fungi. Chemical analysis of one Streptomyces strain led to the discovery of two known compounds and one new compound. These results demonstrated that ant-derived actinobacteria represented an underexplored bioresource library of diverse and novel taxa that may be of potential interest in the discovery of new agroactive compounds.
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Affiliation(s)
- Zhiyan Wang
- Key Laboratory of Agricultural Microbiology of Heilongjiang Province, Northeast Agricultural University, Harbin, China.,State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
| | - Zhiyin Yu
- Key Laboratory of Agricultural Microbiology of Heilongjiang Province, Northeast Agricultural University, Harbin, China.,State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
| | - Junwei Zhao
- Key Laboratory of Agricultural Microbiology of Heilongjiang Province, Northeast Agricultural University, Harbin, China
| | - Xiaoxin Zhuang
- Key Laboratory of Agricultural Microbiology of Heilongjiang Province, Northeast Agricultural University, Harbin, China
| | - Peng Cao
- Key Laboratory of Agricultural Microbiology of Heilongjiang Province, Northeast Agricultural University, Harbin, China
| | - Xiaowei Guo
- Key Laboratory of Agricultural Microbiology of Heilongjiang Province, Northeast Agricultural University, Harbin, China.,State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
| | - Chongxi Liu
- Key Laboratory of Agricultural Microbiology of Heilongjiang Province, Northeast Agricultural University, Harbin, China.,State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
| | - Wensheng Xiang
- Key Laboratory of Agricultural Microbiology of Heilongjiang Province, Northeast Agricultural University, Harbin, China.,State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
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32
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Moccia K, Willems A, Papoulis S, Flores A, Forister ML, Fordyce JA, Lebeis SL. Distinguishing nutrient-dependent plant driven bacterial colonization patterns in alfalfa. ENVIRONMENTAL MICROBIOLOGY REPORTS 2020; 12:70-77. [PMID: 31775178 DOI: 10.1111/1758-2229.12815] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Revised: 11/21/2019] [Accepted: 11/22/2019] [Indexed: 05/23/2023]
Abstract
To understand factors that influence the assembly of microbial communities, we inoculated Medicago sativa with a series of nested bacterial synthetic communities and grew plants in distinct nitrogen concentrations. Two isolates in our eight-member synthetic community, Williamsia sp. R60 and Pantoea sp. R4, consistently dominate community structure across nitrogen regimes. While Pantoea sp. R4 consistently colonizes plants to a higher degree compared to the other six organisms across each community and each nutrient level, Williamsia sp. R60 exhibits nutrient specific colonization differences. Williamsia sp. R60 is more abundant in plants grown at higher nitrogen concentrations, but exhibits the opposite trend when no plant is present, indicating plant-driven influence over colonization. Our research discovered unique, repeatable colonization phenotypes for individual microbes during plant microbiome assembly, and identified alterations caused by the host plant, microbes, and available nutrients.
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Affiliation(s)
- Katherine Moccia
- Department of Microbiology, University of Tennessee, Knoxville, Tennessee
| | - Andrew Willems
- Department of Microbiology, University of Tennessee, Knoxville, Tennessee
| | - Spiridon Papoulis
- Department of Microbiology, University of Tennessee, Knoxville, Tennessee
| | - Alicia Flores
- Department of Microbiology, University of Tennessee, Knoxville, Tennessee
| | | | - James A Fordyce
- Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, Tennessee
| | - Sarah L Lebeis
- Department of Microbiology, University of Tennessee, Knoxville, Tennessee
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Tree Diversity Reduces Fungal Endophyte Richness and Diversity in a Large-Scale Temperate Forest Experiment. DIVERSITY 2019. [DOI: 10.3390/d11120234] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Although decades of research have typically demonstrated a positive correlation between biodiversity of primary producers and associated trophic levels, the ecological drivers of this association are poorly understood. Recent evidence suggests that the plant microbiome, or the fungi and bacteria found on and inside plant hosts, may be cryptic yet important drivers of important processes, including primary production and trophic interactions. Here, using high-throughput sequencing, we characterized foliar fungal community diversity, composition, and function from 15 broadleaved tree species (N = 545) in a recently established, large-scale temperate tree diversity experiment using over 17,000 seedlings. Specifically, we tested whether increases in tree richness and phylogenetic diversity would increase fungal endophyte diversity (the “Diversity Begets Diversity” hypothesis), as well as alter community composition (the “Tree Diversity–Endophyte Community” hypothesis) and function (the “Tree Diversity–Endophyte Function” hypothesis) at different spatial scales. We demonstrated that increasing tree richness and phylogenetic diversity decreased fungal species and functional guild richness and diversity, including pathogens, saprotrophs, and parasites, within the first three years of a forest diversity experiment. These patterns were consistent at the neighborhood and tree plot scale. Our results suggest that fungal endophytes, unlike other trophic levels (e.g., herbivores as well as epiphytic bacteria), respond negatively to increasing plant diversity.
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Ponpandian LN, Rim SO, Shanmugam G, Jeon J, Park YH, Lee SK, Bae H. Phylogenetic characterization of bacterial endophytes from four Pinus species and their nematicidal activity against the pine wood nematode. Sci Rep 2019; 9:12457. [PMID: 31462655 PMCID: PMC6713757 DOI: 10.1038/s41598-019-48745-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Accepted: 07/31/2019] [Indexed: 11/16/2022] Open
Abstract
Recently, bacterial endophytes (BEs) have gained importance in the agricultural sector for their use as biocontrol agents to manage plant pathogens. Outbreak of the pine wilt disease (PWD) in Korea has led researchers to test the feasibility of BEs in controlling the pine wood nematode (PWN) Bursaphelenchus xylophilus. In this study, we have reported the diversity and biocontrol activity of BEs against the PWN. By employing a culture-dependent approach, 1,622 BEs were isolated from the needle, stem, and root tissues of P. densiflora, P. rigida, P. thunbergii, and P. koraiensis across 18 sampling sites in Korea. We classified 389 members based on 16S rDNA analysis and taxonomic binning, of which, 215 operational taxonomic units (OTUs) were determined. Using Shannon’s indices, diversity across the Pinus species and tissues was estimated to reveal the composition of BEs and their tissue-specific preferences. When their ethyl acetate crude extracts were analysed for biocontrol activity, 44 candidates with nematicidal activity were obtained. Among these, Stenotrophomonas and Bacillus sp. exhibited significant inhibitory activity against PWN during their developmental stages. Altogether, our study furnishes a basic comprehension of bacterial communities found in the Pinus species and highlights the potential of BEs as biocontrol agents to combat PWD.
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Affiliation(s)
| | - Soon Ok Rim
- Department of Biotechnology, Yeungnam University, Gyeongsan, Gyeongbuk, 38541, Republic of Korea
| | - Gnanendra Shanmugam
- Department of Biotechnology, Yeungnam University, Gyeongsan, Gyeongbuk, 38541, Republic of Korea
| | - Junhyun Jeon
- Department of Biotechnology, Yeungnam University, Gyeongsan, Gyeongbuk, 38541, Republic of Korea
| | - Young-Hwan Park
- Nakdonggang National Institute of Biological Resources, Sangju, 37242, Republic of Korea
| | - Sun-Keun Lee
- Division of Forest Insect Pests and Diseases, National Institute of Forest Science, Seoul, 02455, Republic of Korea
| | - Hanhong Bae
- Department of Biotechnology, Yeungnam University, Gyeongsan, Gyeongbuk, 38541, Republic of Korea.
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Liu Y, Ponpandian LN, Kim H, Jeon J, Hwang BS, Lee SK, Park SC, Bae H. Distribution and diversity of bacterial endophytes from four Pinus species and their efficacy as biocontrol agents for devastating pine wood nematodes. Sci Rep 2019; 9:12461. [PMID: 31462658 PMCID: PMC6713764 DOI: 10.1038/s41598-019-48739-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Accepted: 07/19/2019] [Indexed: 11/08/2022] Open
Abstract
In this study, we isolated a total of 238 culturable putative bacterial endophytes from four Pinus species (Pinus densiflora, P. koraiensis, P. rigida, and P. thunbergii) across 18 sampling sites in Korea. The samples were cultured in de Man Rogosa Sharpe and humic acid-vitamin agar media. These selective media were used to isolate lactic acid bacteria and Actinobacteria, respectively. Analysis using 16S ribosomal DNA sequencing grouped the isolated putative bacterial endophytes into 107 operational taxonomic units (OTUs) belonging to 48 genera. Gamma-proteobacteria were the most abundant bacteria in each sampling site and three tissues (needle, stem and root). The highest OTU richness and diversity indices were observed in the roots, followed by stem and needle tissues. Total metabolites extracted from three isolates (two isolates of Escherichia coli and Serratia marcescens) showed significant nematicidal activity against the pine wood nematode (Bursaphelenchus xylophilus). Our findings demonstrated the potential use of bacterial endophytes from pine trees as alternative biocontrol agents against pine wood nematodes.
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Affiliation(s)
- Yunran Liu
- Department of Biotechnology, Yeungnam University, Gyeongsan, Gyeongbuk, 38541, Republic of Korea
| | | | - Hoki Kim
- Department of Biotechnology, Yeungnam University, Gyeongsan, Gyeongbuk, 38541, Republic of Korea
| | - Junhyun Jeon
- Department of Biotechnology, Yeungnam University, Gyeongsan, Gyeongbuk, 38541, Republic of Korea
| | - Buyng Su Hwang
- Nakdonggang National Institute of Biological Resources, Sangju, Gyeongbuk, 37242, Republic of Korea
| | - Sun Keun Lee
- Division of Forest Insect Pests and Diseases, National Institute of Forest Science, Seoul, 02455, Republic of Korea
| | - Soo-Chul Park
- Crop Biotechnology Institute, Green Bio Science & Technology, Seoul National University, Pyeongchang, Kangwon, 25354, Republic of Korea
| | - Hanhong Bae
- Department of Biotechnology, Yeungnam University, Gyeongsan, Gyeongbuk, 38541, Republic of Korea.
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Vu THN, Nguyen QH, Dinh TML, Quach NT, Khieu TN, Hoang H, Chu-Ky S, Vu TT, Chu HH, Lee J, Kang H, Li WJ, Phi QT. Endophytic actinomycetes associated with Cinnamomum cassia Presl in Hoa Binh province, Vietnam: Distribution, antimicrobial activity and, genetic features. J GEN APPL MICROBIOL 2019; 66:24-31. [PMID: 31378748 DOI: 10.2323/jgam.2019.04.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Endophytic microbes associated with medicinal plants are considered to be potential producers of various bioactive secondary metabolites. The present study investigated the distribution, antimicrobial activity and genetic features of endophytic actinomycetes isolated from the medicinal plant Cinnamomum cassia Presl collected in Hoa Binh province of northern Vietnam. Based on phenotypic characteristics, 111 actinomycetes were isolated from roots, stems and leaves of the host plants by using nine selective media. The isolated actinomycetes were mainly recovered from stems (n = 67; 60.4%), followed by roots (n = 29; 26.1%) and leaves (n = 15; 13.5%). The isolates were accordingly assigned into 5 color categories of aerial mycelium, of which gray is the most dominant (n = 42; 37.8%), followed by white (n = 33; 29.7%), yellow (n = 25; 22,5%), red (n = 8; 7.2%) and green (n = 3; 2.7%). Of the total endophytic actinomycetes tested, 38 strains (occupying 34.2%) showed antimicrobial activity against at least one of nine tested microbes and, among them, 26 actinomycetes (68.4%) revealed anthracycline-like antibiotics production. Analysis of 16S rRNA gene sequences deposited on GenBank (NCBI) of the antibiotic-producing actinomycetes identified 3 distinct genera, including Streptomyces, Microbacterium, and Nocardia, among which Streptomyces genus was the most dominant and represented 25 different species. Further genetic investigation of the antibiotic-producing actinomycetes found that 28 (73.7%) and 11 (28.9%) strains possessed genes encoding polyketide synthase (pks) and nonribosomal peptide synthetase (nrps), respectively. The findings in the present study highlighted endophytic actinomycetes from C. cassia Presl which possessed broad-spectrum bioactivities with the potential for applications in the agricultural and pharmaceutical sectors.
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Affiliation(s)
- Thi Hanh Nguyen Vu
- Institute of Biotechnology (IBT), Vietnam Academy of Science and Technology (VAST)
| | - Quang Huy Nguyen
- Institute of Biotechnology (IBT), Vietnam Academy of Science and Technology (VAST).,Graduate University of Science and Technology (GUST), Vietnam Academy of Science and Technology (VAST).,University of Science and Technology of Hanoi (USTH), Vietnam Academy of Science and Technology (VAST)
| | - Thi My Linh Dinh
- Institute of Biotechnology (IBT), Vietnam Academy of Science and Technology (VAST)
| | - Ngoc Tung Quach
- Institute of Biotechnology (IBT), Vietnam Academy of Science and Technology (VAST)
| | - Thi Nhan Khieu
- Department of Science, Technology and Environment, Ministry of Education and Training
| | - Ha Hoang
- Institute of Biotechnology (IBT), Vietnam Academy of Science and Technology (VAST)
| | - Son Chu-Ky
- School of Biotechnology and Food Technology (SBFT), Hanoi University of Science and Technology (HUST)
| | - Thu Trang Vu
- School of Biotechnology and Food Technology (SBFT), Hanoi University of Science and Technology (HUST)
| | - Hoang Ha Chu
- Institute of Biotechnology (IBT), Vietnam Academy of Science and Technology (VAST).,Graduate University of Science and Technology (GUST), Vietnam Academy of Science and Technology (VAST)
| | - Jusung Lee
- The Center for Marine Natural Products and Drug Discovery, School of Earth and Environmental Sciences, College of Natural Sciences, Seoul National University NS-80
| | - Heonjoong Kang
- The Center for Marine Natural Products and Drug Discovery, School of Earth and Environmental Sciences, College of Natural Sciences, Seoul National University NS-80.,Research Institute of Oceanography, Seoul National University NS-80
| | - Wen-Jun Li
- State Key Laboratory of Biocontrol and Guangdong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-Sen University
| | - Quyet-Tien Phi
- Institute of Biotechnology (IBT), Vietnam Academy of Science and Technology (VAST).,Graduate University of Science and Technology (GUST), Vietnam Academy of Science and Technology (VAST)
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Gurusinghe S, Brooks TL, Barrow RA, Zhu X, Thotagamuwa A, Dennis PG, Gupta VVSR, Vanniasinkam T, Weston LA. Technologies for the Selection, Culture and Metabolic Profiling of Unique Rhizosphere Microorganisms for Natural Product Discovery. Molecules 2019; 24:E1955. [PMID: 31117282 PMCID: PMC6571749 DOI: 10.3390/molecules24101955] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Revised: 05/15/2019] [Accepted: 05/16/2019] [Indexed: 02/04/2023] Open
Abstract
Small molecule discovery has benefitted from the development of technologies that have aided in the culture and identification of soil microorganisms and the subsequent analysis of their respective metabolomes. We report herein on the use of both culture dependent and independent approaches for evaluation of soil microbial diversity in the rhizosphere of canola, a crop known to support a diverse microbiome, including plant growth promoting rhizobacteria. Initial screening of rhizosphere soils showed that microbial diversity, particularly bacterial, was greatest at crop maturity; therefore organismal recovery was attempted with soil collected at canola harvest. Two standard media (Mueller Hinton and gellan gum) were evaluated following inoculation with soil aqueous suspensions and compared with a novel "rhizochip" prototype buried in a living canola crop rhizosphere for microbial culture in situ. Following successful recovery and identification of 375 rhizosphere microbiota of interest from all culture methods, isolates were identified by Sanger sequencing and/or characterization using morphological and biochemical traits. Three bacterial isolates of interest were randomly selected as case studies for intensive metabolic profiling. After successful culture in liquid media and solvent extraction, individual extracts were subjected to evaluation by UHPLC-DAD-QToF-MS, resulting in the rapid characterization of metabolites of interest from cultures of two isolates. After evaluation of key molecular features, unique or unusual bacterial metabolites were annotated and are reported herein.
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Affiliation(s)
- Saliya Gurusinghe
- Graham Centre for Agricultural Innovation, Charles Sturt University, Wagga Wagga, NSW 2650, Australia.
| | - Tabin L Brooks
- Graham Centre for Agricultural Innovation, Charles Sturt University, Wagga Wagga, NSW 2650, Australia.
- School of Biomedical Sciences, Charles Sturt University, Wagga Wagga, NSW 2650, Australia.
| | - Russell A Barrow
- Graham Centre for Agricultural Innovation, Charles Sturt University, Wagga Wagga, NSW 2650, Australia.
- Plus 3 Australia Pty Ltd, P.O. Box 4345, Hawker, ACT 2614, Australia.
| | - Xiaocheng Zhu
- Graham Centre for Agricultural Innovation, Charles Sturt University, Wagga Wagga, NSW 2650, Australia.
| | - Agasthya Thotagamuwa
- Graham Centre for Agricultural Innovation, Charles Sturt University, Wagga Wagga, NSW 2650, Australia.
| | - Paul G Dennis
- School of Earth and Environmental Sciences, The University of Queensland, Brisbane, QLD 4072, Australia.
| | | | - Thiru Vanniasinkam
- Graham Centre for Agricultural Innovation, Charles Sturt University, Wagga Wagga, NSW 2650, Australia.
- School of Biomedical Sciences, Charles Sturt University, Wagga Wagga, NSW 2650, Australia.
| | - Leslie A Weston
- Graham Centre for Agricultural Innovation, Charles Sturt University, Wagga Wagga, NSW 2650, Australia.
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Chen P, Zhang C, Ju X, Xiong Y, Xing K, Qin S. Community Composition and Metabolic Potential of Endophytic Actinobacteria From Coastal Salt Marsh Plants in Jiangsu, China. Front Microbiol 2019; 10:1063. [PMID: 31139174 PMCID: PMC6527748 DOI: 10.3389/fmicb.2019.01063] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Accepted: 04/26/2019] [Indexed: 12/31/2022] Open
Abstract
The diversity and functional roles of the plant associated endophytic actinobacteria in unique habitats remain poorly understood. In this paper, we examined the phylogenetic diversity and community composition of endophytic actinobacteria associated with native coastal salt marsh plants in Jiangsu, China using a combination of cultivation and 16S rRNA gene-based high-throughput sequencing (HTS) methods. Further, we evaluated the antifungal, fibrinolytic activities and the secondary metabolite biosynthesis potential of isolates via gene screening. A total of 278 actinobacterial isolates were isolated from 19 plant samples. 16S rRNA gene sequencing revealed that the isolates were highly diverse and belonged to 23 genera within the Actinomycetales order, with Streptomyces, Saccharopolyspora, and Pseudonocardia comprising the most abundant genera. In addition, more than 10 of the isolates were novel actinobacterial taxa distributed across eight genera. HTS analyses of seven representative plant root samples revealed that Actinobacteria phylum constituted 0.04–28.66% of root endophytic bacterial communities. A total of four actinobacterial classes, 14 orders, 35 families, and 63 known genera were detected via HTS, and these communities were found to be dominated by the members of the order Actinomycetales including the genera Streptomyces, Mycobacterium, Arthrobacter, Nocardioides, and Micromonospora. In addition, 30.4% of the representative isolates exhibited antifungal activities, 40.5% of them showed fibrinolytic activities, while 43.0% of the strains harbored secondary metabolite biosynthesis genes. These results demonstrated that coastal salt marsh plants in the Jiangsu Province represented an underexplored new reservoir of diverse and novel endophytic actinobacteria that may be of potential interest in the discovery of bioactive compounds with potential as biocontrol agents and for fibrinolytic enzyme production.
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Affiliation(s)
- Pan Chen
- The Key Laboratory of Biotechnology for Medicinal Plant of Jiangsu Province, School of Life Sciences, Jiangsu Normal University, Xuzhou, China
| | - Chunmei Zhang
- The Key Laboratory of Biotechnology for Medicinal Plant of Jiangsu Province, School of Life Sciences, Jiangsu Normal University, Xuzhou, China
| | - Xiuyun Ju
- The Key Laboratory of Biotechnology for Medicinal Plant of Jiangsu Province, School of Life Sciences, Jiangsu Normal University, Xuzhou, China
| | - Youwei Xiong
- The Key Laboratory of Biotechnology for Medicinal Plant of Jiangsu Province, School of Life Sciences, Jiangsu Normal University, Xuzhou, China
| | - Ke Xing
- The Key Laboratory of Biotechnology for Medicinal Plant of Jiangsu Province, School of Life Sciences, Jiangsu Normal University, Xuzhou, China
| | - Sheng Qin
- The Key Laboratory of Biotechnology for Medicinal Plant of Jiangsu Province, School of Life Sciences, Jiangsu Normal University, Xuzhou, China
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39
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Pakchoi Antioxidant Improvement and Differential Rhizobacterial Community Composition under Organic Fertilization. SUSTAINABILITY 2019. [DOI: 10.3390/su11082424] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
A high level of antioxidants in organic-produced vegetables has been attributed to soil conditions; however, little is known about the relationships between antioxidants and rhizobacteria under different fertilization treatments. A pot trial for pakchoi (Brassica campestris ssp. chinensis L.) was conducted under greenhouse conditions with: (1) control; (2) chemical fertilizer; and (3) organic fertilizer. The responses of the plant, soil properties, and rhizobacterial community were measured after 45 days of cultivation. Fertilization increased soil nutrient levels and pakchoi productivity and the reshaped rhizobacterial community structure, while no differences in rhizobacterial abundance and total diversity were observed. Generally, most plant antioxidants were negatively correlated with inorganic nitrogen (N) and positively correlated to organic N in soil. The genera of Arthrospira and Acutodesmus contained differential rhizobacteria under chemical fertilizer treatment, which are known as copiotrophs. In addition, the addition of a chemical fertilizer may stimulate organic substance turnover by the enrichment of organic compound degraders (e.g., Microbacterium and Chitinophaga) and the promotion of predicted functional pathways involved in energy metabolism. Several beneficial rhizobacteria were associated with organic fertilizer amended rhizosphere including the genera Bacillus, Mycobacterium, Actinomycetospora, and Frankia. Furthermore, Bacillus spp. were positively correlated with plant biomass and phenolic acid. Moreover, predictive functional profiles of the rhizobacterial community involved in amino acid metabolism and lipid metabolism were significantly increased under organic fertilization, which were positively correlated with plant antioxidant activity. Overall, our study suggests that the short-term application of chemical and organic fertilizers reshapes the rhizobacterial community structure, and such changes might contribute to the plant’s performance.
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Sakoda S, Aisu K, Imagami H, Matsuda Y. Comparison of Actinomycete Community Composition on the Surface and Inside of Japanese Black Pine (Pinus thunbergii) Tree Roots Colonized by the Ectomycorrhizal Fungus Cenococcum geophilum. MICROBIAL ECOLOGY 2019; 77:370-379. [PMID: 29946784 DOI: 10.1007/s00248-018-1221-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Accepted: 06/05/2018] [Indexed: 06/08/2023]
Abstract
Various bacteria are associated with ectomycorrhizal roots, which are symbiotic complexes formed between plant roots and fungi. Among these associated bacteria, actinomycetes have received attention for their ubiquity and diverse roles in forest ecosystems. Here, to examine the association of actinomycetes with ectomycorrhizal root tips, we compared the bacterial and actinomycete communities on the surface and inside of root tips of coastal Japanese black pine (Pinus thunbergii) colonized by the fungus Cenococcum geophilum. Next-generation sequences of 16S rDNA of bacteria communities using the Ion Torrent Personal Genome Machine showed that the number of bacterial classes in the surface of C. geophilum ECM roots was significantly higher than that in non-ECM roots. The bacterial community structure of surface, inside, and non-ECM roots was significantly discriminated each other. For an isolation method, a total of 762 and 335 actinomycete isolates were obtained from the surface and inside of the roots, respectively. In addition, the isolation ratio of actinomycetes in these root tips varied depending on the age of the tree and the season. Identification of the isolates based on partial 16S rDNA sequencing revealed that the isolates belonged to nine genera of the order Actinomycetales. On the surface of the roots, most of the isolates belonged to genus Streptomyces (90.4%); inside of the roots, most of the isolates belonged to genus Actinoallomurus (40.0%), which is a relatively new taxon. Our results suggest that actinomycetes as well as bacteria are ubiquitously associated with C. geophilum ectomycorrhizal roots of P. thunbergii, although their communities can vary either surface or inside of individual root tips.
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Affiliation(s)
- Shoyo Sakoda
- Laboratory of Forest Mycology, Graduate School of Bioresources, Mie University, Tsu, Mie, 514-8507, Japan.
| | - Kana Aisu
- Laboratory of Forest Pathology and Mycology, Faculty of Bioresources, Mie University, Tsu, Japan
| | - Hiroki Imagami
- Laboratory of Forest Pathology and Mycology, Faculty of Bioresources, Mie University, Tsu, Japan
| | - Yosuke Matsuda
- Laboratory of Forest Mycology, Graduate School of Bioresources, Mie University, Tsu, Mie, 514-8507, Japan.
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Secondary Metabolites of Endophytic Actinomycetes: Isolation, Synthesis, Biosynthesis, and Biological Activities. PROGRESS IN THE CHEMISTRY OF ORGANIC NATURAL PRODUCTS 108 2019; 108:207-296. [DOI: 10.1007/978-3-030-01099-7_3] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Purushotham N, Jones E, Monk J, Ridgway H. Community Structure of Endophytic Actinobacteria in a New Zealand Native Medicinal Plant Pseudowintera colorata (Horopito) and Their Influence on Plant Growth. MICROBIAL ECOLOGY 2018; 76:729-740. [PMID: 29435598 DOI: 10.1007/s00248-018-1153-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Accepted: 01/30/2018] [Indexed: 06/08/2023]
Abstract
The role of plant endophytic Actinobacteria remains poorly understood with no reports of these communities in New Zealand native plants. This first investigation of endophytic Actinobacteria in New Zealand targeted the culturally significant medicinal shrub Pseudowintera colorata (horopito) as a model plant. Community analysis in plant tissues collected from ten geographically distinct sites showed that tissue type had the strongest influence on diversity and richness of endophytic Actinobacteria. More denaturing gradient gel electrophoresis (DGGE) bands were obtained from stems (n = 18) compared to roots (n = 13). Sequencing analysis of the major bands (n = 20) identified them as uncultured bacteria, Streptomyces sp. and Angustibacter peucedani. Using two Actinobacteria-specific media, nine isolates were recovered from surface-sterilised P. colorata tissues. This was approximately 12% of the total taxa and correlated well with culturable numbers in international studies. In vitro analysis of the functionality of these strains showed that Streptomyces sp. PRY2RB2 inhibited all the tested phytopathogenic fungi (n = 4), Streptomyces sp. UKCW/B and Nocardia sp. TP1BA1B solubilised phosphate and produced siderophores. The functionality of the phosphate solubilising strains (n = 2) in vivo was investigated by inoculation of P. colorata seedlings. After 4 months, the mean shoot height of seedlings treated with Nocardia sp. TP1BA1B was 1.65× longer, had higher shoot dry weight (1.6×) and number of internodes (1.67×) compared to control. This study identified for the first time a key group of endophytic Actinobacteria that are likely to be important in the ecology of New Zealand flora.
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Affiliation(s)
- Neeraj Purushotham
- Department of Pest-management and Conservation, Faculty of Agriculture and Life Sciences, Lincoln University, Lincoln, New Zealand.
| | - Eirian Jones
- Department of Pest-management and Conservation, Faculty of Agriculture and Life Sciences, Lincoln University, Lincoln, New Zealand
| | - Jana Monk
- AgResearch, Christchurch, New Zealand
- AsureQuality, Christchurch, New Zealand
| | - Hayley Ridgway
- Department of Pest-management and Conservation, Faculty of Agriculture and Life Sciences, Lincoln University, Lincoln, New Zealand
- Plant & Food Research Ltd, Christchurch, New Zealand
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Kaewkla O, Franco CMM. Actinomycetospora callitridis sp. nov., an endophytic actinobacterium isolated from the surface-sterilised root of an Australian native pine tree. Antonie van Leeuwenhoek 2018; 112:331-337. [PMID: 30225543 DOI: 10.1007/s10482-018-1162-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Accepted: 09/03/2018] [Indexed: 10/28/2022]
Abstract
An endophytic actinobacterium, strain CAP 335T, was isolated from a root sample of a native pine tree growing on the Bedford Park campus of Flinders University, Adelaide, South Australia. The result of a polyphasic study showed that this strain was identified as a new member of the genus Actinomycetospora. This strain was observed to be a Gram stain-positive, aerobic actinobacterium with well-developed substrate mycelia and to form short chains of spores. Actinomycetospora chibensis TT04-21T and Actinomycetospora straminea IY07-55T were found to be close phylogenetic neighbours, each sharing 99.1% 16S rRNA gene similarity. Chemotaxonomic data including major fatty acids, cell wall components and major menaquinones confirmed the affiliation of strain CAP 335T to the genus Actinomycetospora. The phylogenetic analysis, physiological and biochemical studies and DNA-DNA hybridization, allowed the genotypic and phenotypic differentiation of strain CAP 335T and the closely related species with valid names. The name proposed for the new species is Actinomycetospora callitridis sp. nov. The type strain is CAP 335T (= DSM 101857T = NRRL B-65350T).
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Affiliation(s)
- Onuma Kaewkla
- Department of Biology, Faculty of Science, Mahasarakham University, Kantharawichai, Maha Sarakham Province, Thailand.,Department of Medical Biotechnology, College of Medicine and Public Health, Flinders University, Adelaide, Australia
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Singh R, Dubey AK. Diversity and Applications of Endophytic Actinobacteria of Plants in Special and Other Ecological Niches. Front Microbiol 2018; 9:1767. [PMID: 30135681 PMCID: PMC6092505 DOI: 10.3389/fmicb.2018.01767] [Citation(s) in RCA: 78] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Accepted: 07/16/2018] [Indexed: 12/19/2022] Open
Abstract
Actinobacteria are wide spread in nature and represent the largest taxonomic group within the domain Bacteria. They are abundant in soil and have been extensively explored for their therapeutic applications. This versatile group of bacteria has adapted to diverse ecological habitats, which has drawn considerable attention of the scientific community in recent times as it has opened up new possibilities for novel metabolites that may help in solving some of the most challenging problems of the day, for example, novel drugs for drug-resistant human pathogens, affordable means to maintain ecological balance in various habitats, and alternative practices for sustainable agriculture. Traditionally, free dwelling soil actinobacteria have been the subject of intensive research. Of late, symbiotic actinobacteria residing as endophytes within the plant tissues have generated immense interest as potential source of novel compounds, which may find applications in medicine, agriculture, and environment. In the light of these possibilities, this review focuses on the diversity of endophytic actinobacteria isolated from the plants of extreme habitats and specific ecological niches. Furthermore, an attempt has been made to assign chemical class to the compounds obtained from endophytic actinobacteria. Potential therapeutic applications of these compounds and the utility of endophytic actinobacteria in agriculture and environment are discussed.
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Affiliation(s)
| | - Ashok K. Dubey
- Division of Biological Sciences and Engineering, Netaji Subhas Institute of Technology, New Delhi, India
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Washington-Hughes CL, Ford GT, Jones AD, McRae K, Outten FW. Nickel exposure reduces enterobactin production in Escherichia coli. Microbiologyopen 2018; 8:e00691. [PMID: 30062714 PMCID: PMC6460284 DOI: 10.1002/mbo3.691] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Revised: 06/18/2018] [Accepted: 06/19/2018] [Indexed: 12/26/2022] Open
Abstract
Escherichia coli is a well‐studied bacterium that can be found in many niches, such as industrial wastewater, where the concentration of nickel can rise to low‐millimolar levels. Recent studies show that nickel exposure can repress pyochelin or induce pyoverdine siderophore production in Pseudomonas aueroginosa. Understanding the molecular cross‐talk between siderophore production, metal homeostasis, and metal toxicity in microorganisms is critical for designing bioremediation strategies for metal‐contaminated sites. Here, we show that high‐nickel exposure prolongs lag phase duration as a result of low‐intracellular iron levels in E. coli. Although E. coli cells respond to low‐intracellular iron during nickel stress by maintaining high expression of iron uptake systems such as fepA, the demand for iron is not met due to a lack of siderophores in the extracellular medium during nickel stress. Taken together, these results indicate that nickel inhibits iron accumulation in E. coli by reducing the presence of enterobactin in the extracellular medium.
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Affiliation(s)
| | - Geoffrey T Ford
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina
| | - Alsten D Jones
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina
| | - Kimberly McRae
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina
| | - F Wayne Outten
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina
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Zhen H, Krumins V, Fennell DE, Mainelis G. Analysis of airborne microbial communities using 16S ribosomal RNA: Potential bias due to air sampling stress. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 621:939-947. [PMID: 29079080 PMCID: PMC5805565 DOI: 10.1016/j.scitotenv.2017.10.154] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Revised: 10/11/2017] [Accepted: 10/15/2017] [Indexed: 05/16/2023]
Abstract
A limited number of studies have been conducted to analyze ribosomal RNA (rRNA, present in the ribosome) in bioaerosol samples to identify currently or potentially active airborne microbes, although its genomic counterpart, the rRNA gene (on the chromosome) has been frequently targeted for airborne microbial community analysis. A knowledge gap still exists regarding whether the bioaerosol rRNA abundances are affected by the bioaerosol collection process. We investigated the effect of air sampling stress on the measurement and characterization of 16S rRNA for bioaerosols in the laboratory and field experiments using quantitative polymerase chain reaction (qPCR) and high-throughput sequencing techniques. In a laboratory study, known quantities of freshly grown Escherichia coli cells were spiked onto the filter of a Button Aerosol Sampler and into liquids of BioSampler and SpinCon air samplers and then exposed to sampling stress when the samplers were operated for 2h. We found that the recovered cellular 16S rRNA abundance as determined by qPCR was dependent on sampler type. Further, two devices (Button Aerosol Sampler and BioSampler) that exhibited markedly different efficiency in preserving 16S rRNA were employed in an outdoor environment to collect bioaerosols simultaneously on eight days in two different seasons. The abundance of 16S rRNA in the outdoor air sample (1.3×106-4.9×107copies/m3) was about two orders of magnitude higher than that of 16S rRNA gene (6.9×103-1.5×105copies/m3). The 16S rRNA sequences revealed a different bacterial community compared with 16S rRNA gene-based results across all samples, and this difference depended on the sampling device. In addition, a number of bacterial taxa exhibited higher abundance in the 16S rRNA gene sequences than in 16S rRNA sequences, which suggests the potential activities of certain microbes in airborne phase. Overall, this study highlights the importance of sampling device selection when analyzing RNA in bioaerosols.
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Affiliation(s)
- Huajun Zhen
- Rutgers University, Department of Environmental Sciences, 14 College Farm Rd., New Brunswick, NJ 08901, United States
| | - Valdis Krumins
- Rutgers University, Department of Environmental Sciences, 14 College Farm Rd., New Brunswick, NJ 08901, United States
| | - Donna E Fennell
- Rutgers University, Department of Environmental Sciences, 14 College Farm Rd., New Brunswick, NJ 08901, United States
| | - Gediminas Mainelis
- Rutgers University, Department of Environmental Sciences, 14 College Farm Rd., New Brunswick, NJ 08901, United States.
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47
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Kaewkla O, Franco CMM. Promicromonospora callitridis sp. nov., an endophytic actinobacterium isolated from the surface-sterilized root of an Australian native pine tree. Int J Syst Evol Microbiol 2017; 67:3559-3563. [PMID: 28866992 DOI: 10.1099/ijsem.0.002165] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A new strain of the genus Promicromonospora, CAP94T, was isolated from the surface sterilized root of Callitrispreissii (Australian native pine tree). This strain was a Gram-stain-positive, aerobic actinobacterium with hyphae breaking up into fragments which were non-motile, rod-like, coccoid elements. Phylogenetic evaluation based on 16S rRNA gene sequence analysis placed this isolate as a member of the family Promicromonospora ceae, and most closely to Promicromonospora sukumoe NBRC 14650T (99.4 %), Promicromonospora kroppenstedtii DSM 19349T (99.2 %) and Promicromonosporaaerolata V54AT (99.1 %). Chemotaxonomic data including cell-wall components, major menaquinone and major fatty acids confirmed the affiliation of strain CAP94T to the genus Promicromonospora. The results of the phylogenetic analysis, including physiological and biochemical studies in combination with DNA-DNA hybridization, allowed the genotypic and phenotypic differentiation of strain CAP94T and the closest species with validly published names. The name proposed for the new species is Promicromonospora callitridis sp. nov. The type strain is CAP94T (=DSM 103339T=TBRC 6025T).
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Affiliation(s)
- Onuma Kaewkla
- Department of Biology, Faculty of Science, Mahasarakham University, Maha Sarakham Province 44150, Thailand
- Department of Medical Biotechnology, School of Medicine, Flinders University, Bedford Park SA 5042, Australia
| | - Christopher M M Franco
- Department of Medical Biotechnology, School of Medicine, Flinders University, Bedford Park SA 5042, Australia
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48
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Pudasaini S, Wilson J, Ji M, van Dorst J, Snape I, Palmer AS, Burns BP, Ferrari BC. Microbial Diversity of Browning Peninsula, Eastern Antarctica Revealed Using Molecular and Cultivation Methods. Front Microbiol 2017; 8:591. [PMID: 28439263 PMCID: PMC5383709 DOI: 10.3389/fmicb.2017.00591] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Accepted: 03/22/2017] [Indexed: 01/07/2023] Open
Abstract
Browning Peninsula is an ice-free polar desert situated in the Windmill Islands, Eastern Antarctica. The entire site is described as a barren landscape, comprised of frost boils with soils dominated by microbial life. In this study, we explored the microbial diversity and edaphic drivers of community structure across this site using traditional cultivation methods, a novel approach the soil substrate membrane system (SSMS), and culture-independent 454-tag pyrosequencing. The measured soil environmental and microphysical factors of chlorine, phosphate, aspect and elevation were found to be significant drivers of the bacterial community, while none of the soil parameters analyzed were significantly correlated to the fungal community. Overall, Browning Peninsula soil harbored a distinctive microbial community in comparison to other Antarctic soils comprised of a unique bacterial diversity and extremely limited fungal diversity. Tag pyrosequencing data revealed the bacterial community to be dominated by Actinobacteria (36%), followed by Chloroflexi (18%), Cyanobacteria (14%), and Proteobacteria (10%). For fungi, Ascomycota (97%) dominated the soil microbiome, followed by Basidiomycota. As expected the diversity recovered from culture-based techniques was lower than that detected using tag sequencing. However, in the SSMS enrichments, that mimic the natural conditions for cultivating oligophilic “k-selected” bacteria, a larger proportion of rare bacterial taxa (15%), such as Blastococcus, Devosia, Herbaspirillum, Propionibacterium and Methylocella and fungal (11%) taxa, such as Nigrospora, Exophiala, Hortaea, and Penidiella were recovered at the genus level. At phylum level, a comparison of OTU's showed that the SSMS shared 21% of Acidobacteria, 11% of Actinobacteria and 10% of Proteobacteria OTU's with soil. For fungi, the shared OTUs was 4% (Basidiomycota) and <0.5% (Ascomycota). This was the first known attempt to culture microfungi using the SSMS which resulted in an increase in diversity from 14 to 57 microfungi OTUs compared to standard cultivation. Furthermore, the SSMS offers the opportunity to retrieve a greater diversity of bacterial and fungal taxa for future exploitation.
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Affiliation(s)
- Sarita Pudasaini
- School of Biotechnology and Biomolecular Sciences, University of New South WalesKensington, NSW, Australia
| | - John Wilson
- School of Biotechnology and Biomolecular Sciences, University of New South WalesKensington, NSW, Australia
| | - Mukan Ji
- School of Biotechnology and Biomolecular Sciences, University of New South WalesKensington, NSW, Australia
| | - Josie van Dorst
- School of Biotechnology and Biomolecular Sciences, University of New South WalesKensington, NSW, Australia
| | - Ian Snape
- Australian Antarctic Division, Department of Sustainability, Environment, Water, Population and CommunitiesKingston, TAS, Australia
| | - Anne S Palmer
- Australian Antarctic Division, Department of Sustainability, Environment, Water, Population and CommunitiesKingston, TAS, Australia
| | - Brendan P Burns
- School of Biotechnology and Biomolecular Sciences, University of New South WalesKensington, NSW, Australia
| | - Belinda C Ferrari
- School of Biotechnology and Biomolecular Sciences, University of New South WalesKensington, NSW, Australia
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Dinesh R, Srinivasan V, T E S, Anandaraj M, Srambikkal H. Endophytic actinobacteria: Diversity, secondary metabolism and mechanisms to unsilence biosynthetic gene clusters. Crit Rev Microbiol 2017; 43:546-566. [PMID: 28358596 DOI: 10.1080/1040841x.2016.1270895] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Endophytic actinobacteria, which reside in the inner tissues of host plants, are gaining serious attention due to their capacity to produce a plethora of secondary metabolites (e.g. antibiotics) possessing a wide variety of biological activity with diverse functions. This review encompasses the recent reports on endophytic actinobacterial species diversity, in planta habitats and mechanisms underlying their mode of entry into plants. Besides, their metabolic potential, novel bioactive compounds they produce and mechanisms to unravel their hidden metabolic repertoire by activation of cryptic or silent biosynthetic gene clusters (BGCs) for eliciting novel secondary metabolite production are discussed. The study also reviews the classical conservative techniques (chemical/biological/physical elicitation, co-culturing) as well as modern microbiology tools (e.g. next generation sequencing) that are being gainfully employed to uncover the vast hidden scaffolds for novel secondary metabolites produced by these endophytes, which would subsequently herald a revolution in drug engineering. The potential role of these endophytes in the agro-environment as promising biological candidates for inhibition of phytopathogens and the way forward to thoroughly exploit this unique microbial community by inducing expression of cryptic BGCs for encoding unseen products with novel therapeutic properties are also discussed.
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Affiliation(s)
- Raghavan Dinesh
- a ICAR-Indian Institute of Spices Research , Kozhikode, Kerala , India
| | | | - Sheeja T E
- a ICAR-Indian Institute of Spices Research , Kozhikode, Kerala , India
| | | | - Hamza Srambikkal
- a ICAR-Indian Institute of Spices Research , Kozhikode, Kerala , India
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50
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Matsumoto A, Takahashi Y. Endophytic actinomycetes: promising source of novel bioactive compounds. J Antibiot (Tokyo) 2017; 70:514-519. [PMID: 28270688 DOI: 10.1038/ja.2017.20] [Citation(s) in RCA: 82] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Revised: 12/26/2016] [Accepted: 01/26/2017] [Indexed: 12/20/2022]
Abstract
Endophytic actinomycetes associated with plant roots are a relatively untapped source of potential new bioactive compounds. This is becoming increasingly important, as the returns from discovery research on soil-dwelling microbes, have been continuously diminishing. We have isolated more than 1000 strains of actinomycetes from plant roots in our search for novel bioactive compounds, identified and assayed their bioactive metabolites, as well as investigated their biosynthetic genes for generating secondary metabolites. This has resulted in the discovery of several interesting compounds. Creation of plant root clone libraries enabled us to confirm that we had, indeed, isolated endophytes. In this paper, we introduce our approach to this promising line of research, incorporating data from other publications, and illustrate the potential that endophytic actinomycetes offer as a new source of novel lead compounds.
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Affiliation(s)
- Atsuko Matsumoto
- Kitasato Institute for Life Sciences, Laboratory of Microbial Functions, Kitasato University, Tokyo, Japan
| | - Yōko Takahashi
- Kitasato Institute for Life Sciences, Laboratory of Microbial Functions, Kitasato University, Tokyo, Japan
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