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Ghezzi D, Salvi L, Costantini PE, Firrincieli A, Iorio M, Lopo E, Sosio M, Elbanna AH, Khalil ZG, Capon RJ, De Waele J, Vergara F, Sauro F, Cappelletti M. Ancient and remote quartzite caves as a novel source of culturable microbes with biotechnological potential. Microbiol Res 2024; 286:127793. [PMID: 38901277 DOI: 10.1016/j.micres.2024.127793] [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: 02/02/2024] [Revised: 05/23/2024] [Accepted: 05/29/2024] [Indexed: 06/22/2024]
Abstract
Quartzite caves located on table-top mountains (tepuis) in the Guyana Shield, are ancient, remote, and pristine subterranean environments where microbes have evolved peculiar metabolic strategies to thrive in silica-rich, slightly acidic and oligotrophic conditions. In this study, we explored the culturable fraction of the microbiota inhabiting the (ortho)quartzite cave systems in Venezuelan tepui (remote table-top mountains) and we investigated their metabolic and enzymatic activities in relation with silica solubilization and extracellular hydrolytic activities as well as the capacity to produce antimicrobial compounds. Eighty microbial strains were isolated with a range of different enzymatic capabilities. More than half of the isolated strains performed at least three enzymatic activities and four bacterial strains displayed antimicrobial activities. The antimicrobial producers Paraburkholderia bryophila CMB_CA002 and Sphingomonas sp. MEM_CA187, were further analyzed by conducting chemotaxonomy, phylogenomics, and phenomics. While the isolate MEM_CA187 represents a novel species of the genus Sphingomonas, for which the name Sphingomonas imawarii sp. nov. is proposed, P. bryophila CMB_CA002 is affiliated with a few strains of the same species that are antimicrobial producers. Chemical analyses demonstrated that CMB_CA002 produces ditropolonyl sulfide that has a broad range of activity and a possibly novel siderophore. Although the antimicrobial compounds produced by MEM_CA187 could not be identified through HPLC-MS analysis due to the absence of reference compounds, it represents the first soil-associated Sphingomonas strain with the capacity to produce antimicrobials. This work provides first insights into the metabolic potential present in quartzite cave systems pointing out that these environments are a novel and still understudied source of microbial strains with biotechnological potential.
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Affiliation(s)
- Daniele Ghezzi
- Department of Pharmacy and Biotechnology, University of Bologna, Bologna 40126, Italy
| | - Luca Salvi
- Department of Pharmacy and Biotechnology, University of Bologna, Bologna 40126, Italy
| | - Paolo E Costantini
- Department of Pharmacy and Biotechnology, University of Bologna, Bologna 40126, Italy
| | - Andrea Firrincieli
- Department of Pharmacy and Biotechnology, University of Bologna, Bologna 40126, Italy; Department for Innovation in Biological, Agro-Food and Forest systems, University of Tuscia, Viterbo 01100, Italy
| | | | - Ettore Lopo
- Department of Pharmacy and Biotechnology, University of Bologna, Bologna 40126, Italy
| | | | - Ahmed H Elbanna
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia; Department of Pharmacognosy, Cairo University, Cairo 11562, Egypt
| | - Zeinab G Khalil
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Robert J Capon
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Jo De Waele
- Department of Biological, Geological, and Environmental Sciences, University of Bologna, Bologna 40126, Italy; La Venta Geographic Explorations Association, Treviso 31100, Italy
| | - Freddy Vergara
- La Venta Geographic Explorations Association, Treviso 31100, Italy; Teraphosa Exploring Team, Puerto Ordaz, Venezuela
| | - Francesco Sauro
- La Venta Geographic Explorations Association, Treviso 31100, Italy
| | - Martina Cappelletti
- Department of Pharmacy and Biotechnology, University of Bologna, Bologna 40126, Italy; La Venta Geographic Explorations Association, Treviso 31100, Italy.
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2
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Abdelaziz R, Abd El-Hamid MI, El-Wafaei N, Ghaly MF, Askora A, El-Didamony G, AboElmaaty SA, Ismail TA, Ibrahim D, Eissa SA. Phage-resistant Streptomyces abietis and its telomycin bioactive metabolite as a possible alternative to antibiotics. Microb Pathog 2024; 194:106822. [PMID: 39047802 DOI: 10.1016/j.micpath.2024.106822] [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: 05/13/2024] [Revised: 07/19/2024] [Accepted: 07/21/2024] [Indexed: 07/27/2024]
Abstract
Multidrug-resistant pathogens are now thought to be the primary global causes of disease and death. Therefore, it is imperative to develop new effective bioactive compounds from microbial sources, such as Streptomyces species. Nevertheless, the pharmaceutical industry suffered financial losses and low-quality end products as a result of Streptomyces bacteriophage contamination. To reduce the likelihood of phage-induced issues in the medical industry, it is crucial to develop a method for finding phage-resistant strains. Hence, we aimed to isolate and characterize Streptomyces spp. and Streptomyces phages from various rhizospheric soil samples in Egypt and to investigate their antibacterial activities. Moreover, we targeted development of a Streptomyces phage-resistant strain to extract its active metabolites and further testing its antibacterial activity. Herein, the antibacterial activities of the isolated 58 Streptomyces isolates showed that 10 (17.2 %) Streptomyces isolates had antibacterial activities against the tested bacteria including Listeria monocytogenes, E. coli O157, Acinetobacter baumannii, methicillin resistant-vancomycin-intermediate Staphylococcus aureus (MRSA-VISA) and Micrococcus luteus. Three lytic bacteriophages (ϕPRSC1, ϕPRSC2, and ϕPRSC4) belonging to the families Siphoviridae and Podoviridae were obtained from the rhizospheric soil samples using the most potent S. abietis isolate as the host strain. The three isolated Streptomyces phages were thermostable, ultraviolet stable, infectious, and had a wide range of hosts against the 10 tested Streptomyces isolates with antibacterial activities. The DNA of the ϕPRSC1 and ϕPRSC4 phages were resistant to digestion by EcoRI and HindIII, but the DNA of ϕPRSC2 was resistant to digestion by EcoRI and sensitive to digestion by HindIII. Of note, we developed a S. abietis strain resistant to the three isolated phages and its antibacterial activities were twice that of the wild strain. Finally, telomycin was recognized as an antibacterial metabolite extracted from phage-resistant S. abietis strain, which was potent against the tested Gram-positive bacteria including L. monocytogenes, MRSA-VISA, and M. luteus. Thus, our findings open new horizons for researching substitute antimicrobial medications for both existing and reemerging illnesses.
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Affiliation(s)
- Rewan Abdelaziz
- Department of Microbiology, Ain Shams University, Faculty of Science, 11566, Egypt.
| | - Marwa I Abd El-Hamid
- Department of Microbiology, Faculty of Veterinary Medicine, Zagazig University, 44511, Egypt.
| | - Nahed El-Wafaei
- Department of Agricultural Microbiology, Faculty of Agriculture, Zagazig University, 44511, Egypt.
| | - Mohamed F Ghaly
- Department of Botany and Microbiology, Zagazig University, Faculty of Science, Zagazig, 44519, Egypt.
| | - Ahmed Askora
- Department of Botany and Microbiology, Zagazig University, Faculty of Science, Zagazig, 44519, Egypt.
| | - Gamal El-Didamony
- Department of Botany and Microbiology, Zagazig University, Faculty of Science, Zagazig, 44519, Egypt.
| | - Sabah A AboElmaaty
- Department of Botany and Microbiology, Banha University, Faculty of Science, Banha, 44519, Egypt.
| | - Tamer A Ismail
- Department of Clinical Laboratory Sciences, Turabah University College, Taif University, Taif, 21944, Saudi Arabia.
| | - Doaa Ibrahim
- Department of Nutrition and Clinical Nutrition, Faculty of Veterinary Medicine, Zagazig University, Egypt.
| | - Samar A Eissa
- Department of Medical Microbiology and Immunology, Faculty of Medicine-Kafrelsheikh University, 31511, Egypt.
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Stulanovic N, Kerdel Y, Rezende L, Deflandre B, Burguet P, Belde L, Denoel R, Tellatin D, Rigolet A, Hanikenne M, Quinton L, Ongena M, Rigali S. Nitrogen sources enhance siderophore-mediated competition for iron between potato common scab and late blight causative agents. Metallomics 2024; 16:mfae004. [PMID: 38244228 DOI: 10.1093/mtomcs/mfae004] [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: 10/05/2023] [Accepted: 01/18/2024] [Indexed: 01/22/2024]
Abstract
How do pathogens affecting the same host interact with each other? We evaluated here the types of microbe-microbe interactions taking place between Streptomyces scabiei and Phytophthora infestans, the causative agents of common scab and late blight diseases in potato crops, respectively. Under most laboratory culture conditions tested, S. scabiei impaired or completely inhibited the growth of P. infestans by producing either soluble and/or volatile compounds. Increasing peptone levels correlated with increased inhibition of P. infestans. Comparative metabolomics showed that production of S. scabiei siderophores (desferrioxamines, pyochelin, scabichelin, and turgichelin) increased with the quantity of peptone, thereby suggesting that they participate in the inhibition of the oomycete growth. Mass spectrometry imaging further uncovered that the zones of secreted siderophores and of P. infestans growth inhibition coincided. Moreover, either the repression of siderophore production or the neutralization of their iron-chelating activity led to a resumption of P. infestans growth. Replacement of peptone by natural nitrogen sources such as ammonium nitrate, sodium nitrate, ammonium sulfate, and urea also triggered siderophore production in S. scabiei. Interestingly, nitrogen source-induced siderophore production also inhibited the growth of Alternaria solani, the causative agent of the potato early blight. Overall, our work further emphasizes the importance of competition for iron between microorganisms that colonize the same niche. As common scab never alters the vegetative propagation of tubers, we propose that S. scabiei, under certain conditions, could play a protective role for its hosts against much more destructive pathogens through exploitative iron competition and volatile compound production.
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Affiliation(s)
- Nudzejma Stulanovic
- InBioS-Center for Protein Engineering, Institut de Chimie, University of Liège, B-4000 Liège, Belgium
| | - Yasmine Kerdel
- InBioS-Center for Protein Engineering, Institut de Chimie, University of Liège, B-4000 Liège, Belgium
| | - Lucas Rezende
- Hedera-22, Boulevard du Rectorat 27b, B-4000 Liège, Belgium
| | - Benoit Deflandre
- InBioS-Center for Protein Engineering, Institut de Chimie, University of Liège, B-4000 Liège, Belgium
| | - Pierre Burguet
- Molecular Systems (MolSys), Department of Chemistry, University of Liège, B-4000 Liège, Belgium
| | - Loïc Belde
- InBioS-Center for Protein Engineering, Institut de Chimie, University of Liège, B-4000 Liège, Belgium
| | - Romane Denoel
- InBioS-Center for Protein Engineering, Institut de Chimie, University of Liège, B-4000 Liège, Belgium
| | - Déborah Tellatin
- InBioS-Center for Protein Engineering, Institut de Chimie, University of Liège, B-4000 Liège, Belgium
| | - Augustin Rigolet
- Microbial Processes and Interactions, TERRA Teaching and Research Center, BioEcoAgro, Joint Research Unit/UMR transfrontalière 1158, University of Liège-Gembloux Agro-Bio Tech, Gembloux, Belgium
| | - Marc Hanikenne
- InBioS-PhytoSystems, Translational Plant Biology, University of Liège, B-4000 Liège, Belgium
| | - Loïc Quinton
- Molecular Systems (MolSys), Department of Chemistry, University of Liège, B-4000 Liège, Belgium
| | - Marc Ongena
- Microbial Processes and Interactions, TERRA Teaching and Research Center, BioEcoAgro, Joint Research Unit/UMR transfrontalière 1158, University of Liège-Gembloux Agro-Bio Tech, Gembloux, Belgium
| | - Sébastien Rigali
- InBioS-Center for Protein Engineering, Institut de Chimie, University of Liège, B-4000 Liège, Belgium
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Theodorescu M, Bucur R, Bulzu PA, Faur L, Levei EA, Mirea IC, Cadar O, Ferreira RL, Souza-Silva M, Moldovan OT. Environmental Drivers of the Moonmilk Microbiome Diversity in Some Temperate and Tropical Caves. MICROBIAL ECOLOGY 2023; 86:2847-2857. [PMID: 37606696 DOI: 10.1007/s00248-023-02286-8] [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: 05/12/2023] [Accepted: 08/08/2023] [Indexed: 08/23/2023]
Abstract
Moonmilk is a cave deposit that was used for medical and cosmetic purposes and has lately raised interest for its antimicrobial potential. We studied five moonmilk samples from four caves with different microclimatic conditions, two temperate in north-western and northern Romania (Ferice, Fața Apei, and Izvorul Tăușoarelor caves) and one tropical in Minas Gerais, Brazil (Nestor Cave). The physicochemical and mineralogical analyses confirmed the presence of calcite and dolomite as the main phase in the moonmilk. A 16S rRNA gene-based metabarcoding approach showed the most abundant bacteria phyla Proteobacteria, GAL15, Actinobacteriota, and Acidobacteriota. The investigated caves differed in the dominant orders of bacteria, with the highest distance between the Romanian and Nestor Cave samples. Climate and, implicitly, the soil microbiome can be responsible for some differences we found between all the samples. However, other factors can be involved in shaping the moonmilk microbiome, as differences were found between samples in the same cave (Ferice). In our five moonmilk samples, 1 phylum, 70 orders (~ 36%), and 252 genera (~ 47%) were unclassified, which hints at the great potential of cave microorganisms for future uses.
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Affiliation(s)
- Mihail Theodorescu
- Cluj-Napoca Department, Emil Racovita Institute of Speleology, Clinicilor 5, 400006, Cluj-Napoca, Romania
| | - Ruxandra Bucur
- Cluj-Napoca Department, Emil Racovita Institute of Speleology, Clinicilor 5, 400006, Cluj-Napoca, Romania
- Romanian Institute of Science and Technology, Virgil Fulicea 3, 400022, Cluj-Napoca, Romania
| | - Paul-Adrian Bulzu
- Department of Aquatic Microbial Ecology, Institute of Hydrobiology, Biology Centre of the Academy of Sciences of the Czech Republic, 37005, České Budějovice, Czech Republic
| | - Luchiana Faur
- Romanian Institute of Science and Technology, Virgil Fulicea 3, 400022, Cluj-Napoca, Romania
- Emil Racovita Institute of Speleology, 13 Septembrie 13, 050711, Bucharest, Romania
| | - Erika Andrea Levei
- Research Institute for Analytical Instrumentation subsidiary, National Institute of Research and Development for Optoelectronics INOE 2000, Donath 67, 400293, Cluj-Napoca, Romania
| | - Ionuț Cornel Mirea
- Romanian Institute of Science and Technology, Virgil Fulicea 3, 400022, Cluj-Napoca, Romania
- Emil Racovita Institute of Speleology, 13 Septembrie 13, 050711, Bucharest, Romania
| | - Oana Cadar
- Research Institute for Analytical Instrumentation subsidiary, National Institute of Research and Development for Optoelectronics INOE 2000, Donath 67, 400293, Cluj-Napoca, Romania
| | - Rodrigo Lopes Ferreira
- Centro de Estudos em Biologia Subterrânea, Setor de Biodiversidade Subterrânea, Departamento de Ecologia e Conservação, Universidade Federal de Lavras, Campus Universitário, Lavras, Minas Gerais, 37202-553, Brazil
| | - Marconi Souza-Silva
- Centro de Estudos em Biologia Subterrânea, Setor de Biodiversidade Subterrânea, Departamento de Ecologia e Conservação, Universidade Federal de Lavras, Campus Universitário, Lavras, Minas Gerais, 37202-553, Brazil
| | - Oana Teodora Moldovan
- Cluj-Napoca Department, Emil Racovita Institute of Speleology, Clinicilor 5, 400006, Cluj-Napoca, Romania.
- Romanian Institute of Science and Technology, Virgil Fulicea 3, 400022, Cluj-Napoca, Romania.
- Centro Nacional sobre la Evolucion Humana, Paseo Sierra de Atapuerca 3, 09002, Burgos, Spain.
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Kapinusova G, Lopez Marin MA, Uhlik O. Reaching unreachables: Obstacles and successes of microbial cultivation and their reasons. Front Microbiol 2023; 14:1089630. [PMID: 36960281 PMCID: PMC10027941 DOI: 10.3389/fmicb.2023.1089630] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Accepted: 02/10/2023] [Indexed: 03/09/2023] Open
Abstract
In terms of the number and diversity of living units, the prokaryotic empire is the most represented form of life on Earth, and yet it is still to a significant degree shrouded in darkness. This microbial "dark matter" hides a great deal of potential in terms of phylogenetically or metabolically diverse microorganisms, and thus it is important to acquire them in pure culture. However, do we know what microorganisms really need for their growth, and what the obstacles are to the cultivation of previously unidentified taxa? Here we review common and sometimes unexpected requirements of environmental microorganisms, especially soil-harbored bacteria, needed for their replication and cultivation. These requirements include resuscitation stimuli, physical and chemical factors aiding cultivation, growth factors, and co-cultivation in a laboratory and natural microbial neighborhood.
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Affiliation(s)
| | | | - Ondrej Uhlik
- Department of Biochemistry and Microbiology, Faculty of Food and Biochemical Technology, University of Chemistry and Technology, Prague, Czechia
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Martinet L, Naômé A, Rezende LCD, Tellatin D, Pignon B, Docquier JD, Sannio F, Baiwir D, Mazzucchelli G, Frédérich M, Rigali S. Lunaemycins, New Cyclic Hexapeptide Antibiotics from the Cave Moonmilk-Dweller Streptomyces lunaelactis MM109 T. Int J Mol Sci 2023; 24:ijms24021114. [PMID: 36674628 PMCID: PMC9866976 DOI: 10.3390/ijms24021114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 01/01/2023] [Accepted: 01/04/2023] [Indexed: 01/09/2023] Open
Abstract
Streptomyces lunaelactis strains have been isolated from moonmilk deposits, which are calcium carbonate speleothems used for centuries in traditional medicine for their antimicrobial properties. Genome mining revealed that these strains are a remarkable example of a Streptomyces species with huge heterogeneity regarding their content in biosynthetic gene clusters (BGCs) for specialized metabolite production. BGC 28a is one of the cryptic BGCs that is only carried by a subgroup of S. lunaelactis strains for which in silico analysis predicted the production of nonribosomal peptide antibiotics containing the non-proteogenic amino acid piperazic acid (Piz). Comparative metabolomics of culture extracts of S. lunaelactis strains either holding or not holding BGC 28a combined with MS/MS-guided peptidogenomics and 1H/13C NMR allowed us to identify the cyclic hexapeptide with the amino acid sequence (D-Phe)-(L-HO-Ile)-(D-Piz)-(L-Piz)-(D-Piz)-(L-Piz), called lunaemycin A, as the main compound synthesized by BGC 28a. Molecular networking further identified 18 additional lunaemycins, with 14 of them having their structure elucidated by HRMS/MS. Antimicrobial assays demonstrated a significant bactericidal activity of lunaemycins against Gram-positive bacteria, including multi-drug resistant clinical isolates. Our work demonstrates how an accurate in silico analysis of a cryptic BGC can highly facilitate the identification, the structural elucidation, and the bioactivity of its associated specialized metabolites.
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Affiliation(s)
- Loïc Martinet
- InBioS—Centre for Protein Engineering, Institut de Chimie B6a, University of Liège, B-4000 Liege, Belgium
- Hedera-22, Boulevard du Rectorat 27b, B-4000 Liege, Belgium
| | - Aymeric Naômé
- InBioS—Centre for Protein Engineering, Institut de Chimie B6a, University of Liège, B-4000 Liege, Belgium
- Hedera-22, Boulevard du Rectorat 27b, B-4000 Liege, Belgium
| | | | - Déborah Tellatin
- InBioS—Centre for Protein Engineering, Institut de Chimie B6a, University of Liège, B-4000 Liege, Belgium
| | - Bernard Pignon
- InBioS—Centre for Protein Engineering, Institut de Chimie B6a, University of Liège, B-4000 Liege, Belgium
| | - Jean-Denis Docquier
- InBioS—Centre for Protein Engineering, Institut de Chimie B6a, University of Liège, B-4000 Liege, Belgium
- Dipartimento di Biotecnologie Mediche, University of Siena, Viale Bracci 16, 53100 Siena, Italy
| | - Filomena Sannio
- Dipartimento di Biotecnologie Mediche, University of Siena, Viale Bracci 16, 53100 Siena, Italy
| | - Dominique Baiwir
- GIGA Proteomics Facility, University of Liege, B-4000 Liege, Belgium
| | - Gabriel Mazzucchelli
- Mass Spectrometry Laboratory, MolSys Research Unit, University of Liege, B-4000 Liege, Belgium
| | - Michel Frédérich
- Laboratory of Pharmacognosy, Center of Interdisciplinary Research on Medicines (CIRM), University of Liege, B-4000 Liege, Belgium
| | - Sébastien Rigali
- InBioS—Centre for Protein Engineering, Institut de Chimie B6a, University of Liège, B-4000 Liege, Belgium
- Hedera-22, Boulevard du Rectorat 27b, B-4000 Liege, Belgium
- Correspondence:
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González-Salazar LA, Quezada M, Rodríguez-Orduña L, Ramos-Aboites H, Capon RJ, Souza-Saldívar V, Barona-Gomez F, Licona-Cassani C. Biosynthetic novelty index reveals the metabolic potential of rare actinobacteria isolated from highly oligotrophic sediments. Microb Genom 2023; 9:mgen000921. [PMID: 36748531 PMCID: PMC9973853 DOI: 10.1099/mgen.0.000921] [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] [Indexed: 01/21/2023] Open
Abstract
Calculations predict that testing of 5 000-10 000 molecules and >1 billion US dollars (£0.8 billion, £1=$1.2) are required for one single drug to come to the market. A solution to this problem is to establish more efficient protocols that reduce the high rate of re-isolation and continuous rediscovery of natural products during early stages of the drug development process. The study of 'rare actinobacteria' has emerged as a possible approach for increasing the discovery rate of drug leads from natural sources. Here, we define a simple genomic metric, defined as biosynthetic novelty index (BiNI), that can be used to rapidly rank strains according to the novelty of the subset of encoding biosynthetic clusters. By comparing a subset of high-quality genomes from strains of different taxonomic and ecological backgrounds, we used the BiNI score to support the notion that rare actinobacteria encode more biosynthetic gene cluster (BGC) novelty. In addition, we present the isolation and genomic characterization, focused on specialized metabolites and phenotypic screening, of two isolates belonging to genera Lentzea and Actinokineospora from a highly oligotrophic environment. Our results show that both strains harbour a unique subset of BGCs compared to other members of the genera Lentzea and Actinokineospora. These BGCs are responsible for potent antimicrobial and cytotoxic bioactivity. The experimental data and analysis presented in this study contribute to the knowledge of genome mining analysis in rare actinobacteria and, most importantly, can serve to direct sampling efforts to accelerate early stages of the drug discovery pipeline.
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Affiliation(s)
- Luz A González-Salazar
- Industrial Genomics Laboratory, Escuela de Ingeniería y Ciencias, Tecnológico de Monterrey, Nuevo León, Mexico
| | - Michelle Quezada
- Institute for Molecular Bioscience, University of Queensland, St Lucia, Queensland 4072, Australia
| | - Lorena Rodríguez-Orduña
- Industrial Genomics Laboratory, Escuela de Ingeniería y Ciencias, Tecnológico de Monterrey, Nuevo León, Mexico
| | - Hilda Ramos-Aboites
- Evolution of Metabolic Diversity Laboratory, Unidad de Genómica Avanza (LANGEBIO), Cinvestav-IPN, Irapuato, Mexico
| | - Robert J Capon
- Institute for Molecular Bioscience, University of Queensland, St Lucia, Queensland 4072, Australia
| | - Valeria Souza-Saldívar
- Departamento de Ecología Evolutiva, Instituto de Ecología, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
| | - Francisco Barona-Gomez
- Evolution of Metabolic Diversity Laboratory, Unidad de Genómica Avanza (LANGEBIO), Cinvestav-IPN, Irapuato, Mexico.,Present address: Microbial Diversity and Specialized Metabolism Laboratory, Institute of Biology, Leiden University, Leiden, Netherlands
| | - Cuauhtémoc Licona-Cassani
- Industrial Genomics Laboratory, Escuela de Ingeniería y Ciencias, Tecnológico de Monterrey, Nuevo León, Mexico.,Division of Integrative Biology, Institute for Obesity Research, Tecnológico de Monterrey, Nuevo León, Mexico
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8
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Watanabe M, Igarashi K, Kato S, Kamagata Y, Kitagawa W. Self-cloning of the Catalase Gene in Environmental Isolates Improves Their Colony-forming Abilities on Agar Media. Microbes Environ 2023; 38:n/a. [PMID: 37302843 DOI: 10.1264/jsme2.me23006] [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: 06/13/2023] Open
Abstract
Hydrogen peroxide (H2O2) inhibits microbial growth at a specific concentration. However, we previously isolated two environmental bacterial strains that exhibited sensitivity to a lower H2O2 concentration in agar plates. Putative catalase genes, which degrade H2O2, were detected in their genomes. We herein elucidated the characteristics of these putative genes and their products using a self-cloning technique. The products of the cloned genes were identified as functional catalases. The up-regulation of their expression increased the colony-forming ability of host cells under H2O2 pressure. The present results demonstrated high sensitivity to H2O2 even in microbes possessing functional catalase genes.
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Affiliation(s)
- Motoyuki Watanabe
- Graduate School of Agriculture, Hokkaido University
- Bioproduction Research Institute, National Institute of Advanced Industrial and Technology (AIST)
| | - Kensuke Igarashi
- Graduate School of Global Food Resources, Hokkaido University
- Bioproduction Research Institute, National Institute of Advanced Industrial and Technology (AIST)
| | - Souichiro Kato
- Graduate School of Agriculture, Hokkaido University
- Bioproduction Research Institute, National Institute of Advanced Industrial and Technology (AIST)
| | - Yoichi Kamagata
- Graduate School of Agriculture, Hokkaido University
- Bioproduction Research Institute, National Institute of Advanced Industrial and Technology (AIST)
| | - Wataru Kitagawa
- Graduate School of Agriculture, Hokkaido University
- Bioproduction Research Institute, National Institute of Advanced Industrial and Technology (AIST)
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9
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Pipite A, Lockhart PJ, McLenachan PA, Christi K, Kumar D, Prasad S, Subramani R. Isolation, antibacterial screening, and identification of bioactive cave dwelling bacteria in Fiji. Front Microbiol 2022; 13:1012867. [PMID: 36605510 PMCID: PMC9807670 DOI: 10.3389/fmicb.2022.1012867] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2022] [Accepted: 11/14/2022] [Indexed: 12/24/2022] Open
Abstract
Bacteria are well known producers of bioactive secondary metabolites, including some of the most effective antibiotics in use today. While the caves of Oceania are still largely under-explored, they form oligotrophic and extreme environments that are a promising source for identifying novel species of bacteria with biologically active compounds. By using selective media that mimicked a cave environment, and pretreatments that suppressed the growth of fast-growing bacteria, we have cultured genetically diverse bacteria from a limestone cave in Fiji. Partial 16S rRNA gene sequences from isolates were determined and compared with 16S rRNA gene sequences in EzBioCloud and SILVA data bases. Fifty-five isolates purified from culture had Actinomycete-like morphologies and these were investigated for antibacterial activity. Initial screening using a cross streak test with pathogenic bacteria indicated that 34 of the isolates had antibacterial properties. The best matches for the isolates are bacteria with potential uses in the manufacture of antibiotics and pesticides, in bioremediation of toxic waste, in biomining, in producing bioplastics, and in plant growth promotion. Nineteen bacteria were confirmed as Actinomycetes. Thirteen were from the genus Streptomyces and six from genera considered to be rare Actinomycetes from Pseudonocardia, Kocuria, Micromonospora, Nonomuraea. Ten isolates were Firmicutes from the genera Bacillus, Lysinbacillus, Psychrobacillus and Fontibacillus. Two were Proteobacteria from the genera Mesorhizobium and Cupriavidus. Our findings identify a potentially rich source of microbes for applications in biotechnologies.
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Affiliation(s)
- Atanas Pipite
- School of Agriculture, Geography, Environment, Ocean and Natural Sciences (SAGEONS), The University of the South Pacific, Suva, Fiji,*Correspondence: Atanas Pipite,
| | - Peter J. Lockhart
- School of Natural Sciences, Massey University, Palmerston North, New Zealand,Peter J. Lockhart,
| | | | - Ketan Christi
- School of Agriculture, Geography, Environment, Ocean and Natural Sciences (SAGEONS), The University of the South Pacific, Suva, Fiji
| | - Dinesh Kumar
- School of Agriculture, Geography, Environment, Ocean and Natural Sciences (SAGEONS), The University of the South Pacific, Suva, Fiji
| | - Surendra Prasad
- School of Agriculture, Geography, Environment, Ocean and Natural Sciences (SAGEONS), The University of the South Pacific, Suva, Fiji
| | - Ramesh Subramani
- School of Agriculture, Geography, Environment, Ocean and Natural Sciences (SAGEONS), The University of the South Pacific, Suva, Fiji
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10
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Zhu HZ, Jiang CY, Liu SJ. Microbial roles in cave biogeochemical cycling. Front Microbiol 2022; 13:950005. [PMID: 36246268 PMCID: PMC9554484 DOI: 10.3389/fmicb.2022.950005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2022] [Accepted: 09/14/2022] [Indexed: 11/23/2022] Open
Abstract
Among fundamental research questions in subterranean biology, the role of subterranean microbiomes playing in key elements cycling is a top-priority one. Karst caves are widely distributed subsurface ecosystems, and cave microbes get more and more attention as they could drive cave evolution and biogeochemical cycling. Research have demonstrated the existence of diverse microbes and their participance in biogeochemical cycling of elements in cave environments. However, there are still gaps in how these microbes sustain in caves with limited nutrients and interact with cave environment. Cultivation of novel cave bacteria with certain functions is still a challenging assignment. This review summarized the role of microbes in cave evolution and mineral deposition, and intended to inspire further exploration of microbial performances on C/N/S biogeocycles.
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Affiliation(s)
- Hai-Zhen Zhu
- State Key Laboratory of Microbial Resources and Environmental Microbiology Research Center, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Cheng-Ying Jiang
- State Key Laboratory of Microbial Resources and Environmental Microbiology Research Center, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Shuang-Jiang Liu
- State Key Laboratory of Microbial Resources and Environmental Microbiology Research Center, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
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11
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Reboleira AS, Bodawatta KH, Ravn NMR, Lauritzen SE, Skoglund RØ, Poulsen M, Michelsen A, Jønsson KA. Nutrient-limited subarctic caves harbour more diverse and complex bacterial communities than their surface soil. ENVIRONMENTAL MICROBIOME 2022; 17:41. [PMID: 35941623 PMCID: PMC9361705 DOI: 10.1186/s40793-022-00435-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Accepted: 07/08/2022] [Indexed: 06/15/2023]
Abstract
BACKGROUND Subarctic regions are particularly vulnerable to climate change, yet little is known about nutrient availability and biodiversity of their cave ecosystems. Such knowledge is crucial for predicting the vulnerability of these ecosystems to consequences of climate change. Thus, to improve our understanding of life in these habitats, we characterized environmental variables, as well as bacterial and invertebrate communities of six subarctic caves in Northern Norway. RESULTS Only a minuscule diversity of surface-adapted invertebrates were found in these caves. However, the bacterial communities in caves were compositionally different, more diverse and more complex than the nutrient-richer surface soil. Cave soil microbiomes were less variable between caves than between surface communities in the same area, suggesting that the stable cave environments with tougher conditions drive the uniform microbial communities. We also observed only a small proportion of cave bacterial genera originating from the surface, indicating unique cave-adapted microbial communities. Increased diversity within caves may stem from higher niche specialization and levels of interdependencies for nutrient cycling among bacterial taxa in these oligotrophic environments. CONCLUSIONS Taken together this suggest that environmental changes, e.g., faster melting of snow as a result of global warming that could alter nutrient influx, can have a detrimental impact on interactions and dependencies of these complex communities. This comparative exploration of cave and surface microbiomes also lays the foundation to further investigate the long-term environmental variables that shape the biodiversity of these vulnerable ecosystems.
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Affiliation(s)
- Ana Sofia Reboleira
- Departamento de Biologia Animal, and Centre for Ecology, Evolution and Environmental Changes (cE3c) & CHANGE - Global Change and Sustainability Institute, Faculdade de Ciências, Universidade de Lisboa, 1749-016, Lisbon, Portugal.
- Natural History Museum of Denmark, University of Copenhagen, Universitetsparken 15, 2100, Copenhagen East, Denmark.
| | - Kasun H Bodawatta
- Departamento de Biologia Animal, and Centre for Ecology, Evolution and Environmental Changes (cE3c) & CHANGE - Global Change and Sustainability Institute, Faculdade de Ciências, Universidade de Lisboa, 1749-016, Lisbon, Portugal
- Natural History Museum of Denmark, University of Copenhagen, Universitetsparken 15, 2100, Copenhagen East, Denmark
| | - Nynne M R Ravn
- Natural History Museum of Denmark, University of Copenhagen, Universitetsparken 15, 2100, Copenhagen East, Denmark
| | - Stein-Erik Lauritzen
- Department of Earth Science, University of Bergen, Allegt. 41, 5007, Bergen, Norway
- Department of Biosciences, Centre for Ecological and Evolutionary Synthesis (CEES), University of Oslo, 0316, Oslo, Norway
| | | | - Michael Poulsen
- Section for Ecology and Evolution, Department of Biology, University of Copenhagen, Universitetsparken 15, 2100, Copenhagen East, Denmark
| | - Anders Michelsen
- Section for Terrestrial Ecology, Department of Biology, University of Copenhagen, Universitetsparken 15, 2100, Copenhagen East, Denmark
| | - Knud Andreas Jønsson
- Natural History Museum of Denmark, University of Copenhagen, Universitetsparken 15, 2100, Copenhagen East, Denmark
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12
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Barbato M, Vacchini V, Engelen AH, Patania G, Mapelli F, Borin S, Crotti E. What lies on macroalgal surface: diversity of polysaccharide degraders in culturable epiphytic bacteria. AMB Express 2022; 12:98. [PMID: 35895126 PMCID: PMC9329506 DOI: 10.1186/s13568-022-01440-8] [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: 06/20/2022] [Accepted: 07/13/2022] [Indexed: 11/10/2022] Open
Abstract
Macroalgal surface constitutes a peculiar ecological niche and an advantageous substratum for microorganisms able to degrade the wide diversity of algal glycans. The degrading enzymatic activities of macroalgal epiphytes are of paramount interest for the industrial by-product sector and biomass resource applications. We characterized the polysaccharide hydrolytic profile of bacterial isolates obtained from three macroalgal species: the red macroalgae Asparagopsis taxiformis and Sphaerococcus coronopifolius (Rhodophyceae) and the brown Halopteris scoparia (Phaeophyceae), sampled in South Portugal. Bacterial enrichment cultures supplemented with chlorinated aliphatic compounds, typically released by marine algae, were established using as inoculum the decaying biomass of the three macroalgae, obtaining a collection of 634 bacterial strains. Although collected from the same site and exposed to the same seawater seeding microbiota, macroalgal cultivable bacterial communities in terms of functional and phylogenetic diversity showed host specificity. Isolates were tested for the hydrolysis of starch, pectin, alginate and agar, exhibiting a different hydrolytic potential according to their host: A. taxiformis showed the highest percentage of active isolates (91%), followed by S. coronopifolius (54%) and H. scoparia (46%). Only 30% of the isolates were able to degrade starch, while the other polymers were degraded by 55-58% of the isolates. Interestingly, several isolates showed promiscuous capacities to hydrolyze more than one polysaccharide. The isolate functional fingerprint was statistically correlated to bacterial phylogeny, host species and enrichment medium. In conclusion, this work depicts macroalgae as holobionts with an associated microbiota of interest for blue biotechnologies, suggesting isolation strategies and bacterial targets for polysaccharidases' discovery.
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Affiliation(s)
- Marta Barbato
- Dipartimento di Scienze per gli Alimenti, la Nutrizione e l'Ambiente (DeFENS), Università degli Studi di Milano, via Celoria 2, 20133, Milano, Italy.,Department of Biology, Section for Microbiology, Aarhus University, Ny Munkegade 116, 8000, Aarhus, Denmark
| | - Violetta Vacchini
- Dipartimento di Scienze per gli Alimenti, la Nutrizione e l'Ambiente (DeFENS), Università degli Studi di Milano, via Celoria 2, 20133, Milano, Italy
| | - Aschwin H Engelen
- Centro de Ciências do Mar (CCMAR), Universidade do Algarve, Campus de Gambelas, 8005-139, Faro, Portugal
| | - Giovanni Patania
- Dipartimento di Scienze per gli Alimenti, la Nutrizione e l'Ambiente (DeFENS), Università degli Studi di Milano, via Celoria 2, 20133, Milano, Italy
| | - Francesca Mapelli
- Dipartimento di Scienze per gli Alimenti, la Nutrizione e l'Ambiente (DeFENS), Università degli Studi di Milano, via Celoria 2, 20133, Milano, Italy
| | - Sara Borin
- Dipartimento di Scienze per gli Alimenti, la Nutrizione e l'Ambiente (DeFENS), Università degli Studi di Milano, via Celoria 2, 20133, Milano, Italy.
| | - Elena Crotti
- Dipartimento di Scienze per gli Alimenti, la Nutrizione e l'Ambiente (DeFENS), Università degli Studi di Milano, via Celoria 2, 20133, Milano, Italy
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13
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Martinet L, Baiwir D, Mazzucchelli G, Rigali S. Structure of New Ferroverdins Recruiting Unconventional Ferrous Iron Chelating Agents. Biomolecules 2022; 12:biom12060752. [PMID: 35740878 PMCID: PMC9221444 DOI: 10.3390/biom12060752] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 05/19/2022] [Accepted: 05/20/2022] [Indexed: 11/16/2022] Open
Abstract
Ferroverdins are ferrous iron (Fe2+)-nitrosophenolato complexes produced by a few Streptomyces species as a response to iron overload. Previously, three ferroverdins were identified: ferroverdin A, in which three molecules of p-vinylphenyl-3-nitroso-4-hydroxybenzoate (p-vinylphenyl-3,4-NHBA) are recruited to bind Fe2+, and Ferroverdin B and Ferroverdin C, in which one molecule of p-vinylphenyl-3,4-NHBA is substituted by hydroxy-p-vinylphenyl-3,4-NHBA, and by carboxy-p-vinylphenyl-3,4-NHBA, respectively. These molecules, especially ferroverdin B, are potent inhibitors of the human cholesteryl ester transfer protein (CETP) and therefore candidate hits for the development of drugs that increase the serum concentration of high-density lipoprotein cholesterol, thereby diminishing the risk of atherosclerotic cardiovascular disease. In this work, we used high-resolution mass spectrometry combined with tandem mass spectrometry to identify 43 novel ferroverdins from the cytosol of two Streptomyces lunaelactis species. For 13 of them (designated ferroverdins C2, C3, D, D2, D3, E, F, G, H, CD, DE, DF, and DG), we could elucidate their structure, and for the other 17 new ferroverdins, ambiguity remains for one of the three ligands. p-formylphenyl-3,4-NHBA, p-benzoic acid-3,4-NHBA, 3,4-NHBA, p-phenylpropionate-3,4-NHBA, and p-phenyacetate-3,4-NHBA were identified as new alternative chelators for Fe2+-binding, and two compounds (C3 and D3) are the first reported ferroverdins that do not recruit p-vinylphenyl-3,4-NHBA. Our work thus uncovered putative novel CETP inhibitors or ferroverdins with novel bioactivities.
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Affiliation(s)
- Loïc Martinet
- InBioS, Center for Protein Engineering, University of Liege, B-4000 Liege, Belgium
- Hedera-22, Boulevard du Rectorat 27b, B-4000 Liege, Belgium;
| | - Dominique Baiwir
- GIGA Proteomics Facility, University of Liege, B-4000 Liege, Belgium;
| | - Gabriel Mazzucchelli
- Mass Spectrometry Laboratory, MolSys Research Unit, University of Liege, B-4000 Liege, Belgium;
| | - Sébastien Rigali
- InBioS, Center for Protein Engineering, University of Liege, B-4000 Liege, Belgium
- Hedera-22, Boulevard du Rectorat 27b, B-4000 Liege, Belgium;
- Correspondence:
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14
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Next-Generation Sequencing Results Vary Between Cultured and Uncultured Microbes. Curr Microbiol 2022; 79:187. [PMID: 35524899 DOI: 10.1007/s00284-022-02865-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Accepted: 04/05/2022] [Indexed: 11/03/2022]
Abstract
Next-generation sequencing (NGS) technology has led to innovations in environmental metagenomics and investigations involving humans and microbes. However, it is necessary to analyze the components that will affect analysis of the method upon processing a large amount of information. In particular, the processing method after sample collection affects the NGS results, and it is necessary to check for inaccurate results. Here, we show that the microbial communities obtained from fingertip samples differ from those obtained from fingertips remaining on mobile phones and desks, when cultured or not for 24 h. We also confirmed changes in microbial communities in fingertip samples from desks incubated for 2, 4, 8, 16, and 24 h. Samples of prints from mobile phones that are considerably vulnerable to external factors were not analyzed. Ratios of Firmicutes and Bacillus were, respectively, increased in cultures at the phylum and species levels. Collectively, we identified bacterial species that can aid in determining whether a sample has been cultured. In addition, although microbial communities differed depending on sample types, we confirmed changes after culture for 4 and 8 h. However, since this study is a sample limited to three types, it is necessary to analyze other types of samples in the same way and check whether they are applicable to all types. This strategy can verify the suitability of samples for deriving informative results from cultured or uncultured bacterial communities.
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15
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Sedeek AM, Ismail MM, Elsayed TR, Ramadan MA. Recent methods for discovering novel bioactive metabolites, specifically antimicrobial agents, from marine-associated microorganisms. Lett Appl Microbiol 2022; 75:511-525. [PMID: 35485872 DOI: 10.1111/lam.13728] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 03/08/2022] [Accepted: 04/19/2022] [Indexed: 12/01/2022]
Abstract
Marine microorganisms are a promising source for novel natural compounds with many medical and biotechnological applications. Here we demonstrate limitations and recent strategies for investigating the marine microbial community for novel bioactive metabolites, specifically those of antimicrobial potential. These strategies include culture-dependent methods such as modifying the standard culture media, including changing the gelling agent, dissolving vehicle, media supplementation, and preparation to access a broader range of bacterial diversity from marine samples. Furthermore, we discuss strategies like in situ cultivation, dilution-to-extinction cultivation, and long-term incubation. We are presenting recent applications of culture-independent methods such as genome mining, proteomics profiling, and the application of metagenomics as a novel strategy for structure confirmation in the discovery of the marine microorganism for novel antimicrobial metabolites. We present this review as a simple guide and a helpful resource for those who seek to enter the challenging field of applied marine microbiology.
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Affiliation(s)
- Abdelrahman M Sedeek
- Department of Microbiology and Immunology, Faculty of Pharmacy, Sinai University, Ismaillia, 41522, Egypt
| | - Maha M Ismail
- Department of Microbiology and Immunology, Faculty of Pharmacy, Cairo University, Cairo, 11562, Egypt
| | - Tarek R Elsayed
- Department of Agricultural Microbiology, Faculty of Agriculture, Cairo University, Egypt, Giza, 12613, Egypt
| | - Mohamed A Ramadan
- Department of Microbiology and Immunology, Faculty of Pharmacy, Cairo University, Cairo, 11562, Egypt
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16
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Into the Unknown: Microbial Communities in Caves, Their Role, and Potential Use. Microorganisms 2022; 10:microorganisms10020222. [PMID: 35208677 PMCID: PMC8877592 DOI: 10.3390/microorganisms10020222] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 01/10/2022] [Accepted: 01/15/2022] [Indexed: 02/05/2023] Open
Abstract
Caves have been an item of amateur and professional exploration for many years. Research on the karst caves has revealed great diversity of bacteria, algae, and fungi living on stone walls and speleothems, in mud puddles or sediments. They have become the source of interest for various research groups including geologists, chemists, ecologists, or microbiologists. The adaptations of cave-dwelling organisms applied to their survival are complex and some of their properties show potential to be used in various areas of human life. Secondary metabolites produced by cave’s bacteria show strong antimicrobial, anti-inflammatory, or anticancer properties. Furthermore, bacteria that can induce mineral precipitation could be used in the construction industry and for neutralization of radioisotopes. In this review we focus on bacteria and algae present in cave ecosystems, their role in shaping such specific environment, and their biotechnological and medical potential.
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17
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Comparative Analysis of the Cultured and Total Bacterial Community in the Wheat Rhizosphere Microbiome Using Culture-Dependent and Culture-Independent Approaches. Microbiol Spectr 2021; 9:e0067821. [PMID: 34668733 PMCID: PMC8528112 DOI: 10.1128/spectrum.00678-21] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Rhizosphere and root-associated bacteria are key components of crop production and sustainable agriculture. However, utilization of these beneficial bacteria is often limited by conventional culture techniques because a majority of soil microorganisms cannot be cultured using standard laboratory media. Therefore, the purpose of this study was to improve culturability and investigate the diversity of the bacterial communities from the wheat rhizosphere microbiome collected from three locations in Egypt with contrasting soil characteristics by using metagenomic analysis and improved culture-based methods. The improved strategies of the culture-dependent approach included replacing the agar in the medium with gellan gums and modifying its preparation by autoclaving the phosphate and gelling agents separately. Compared to the total operational taxonomic units (OTUs) observed from the metagenomic data sets derived from the three analyzed soils, 1.86 to 2.52% of the bacteria were recovered using the modified cultivation strategies, whereas less than 1% were obtained employing the standard cultivation protocols. Twenty-one percent of the cultivable isolates exhibited multiple plant growth-promoting (PGP) properties, including P solubilization activity and siderophore production. From the metagenomic analysis, the most abundant phyla were Proteobacteria, Actinobacteria, Chloroflexi, Bacteroidetes, and Firmicutes. Moreover, the relative abundance of the specific bacterial taxa was correlated with the soil characteristics, demonstrating the effect of the soil in modulating the plant rhizosphere microbiome. IMPORTANCE Bacteria colonizing the rhizosphere, a narrow zone of soil surrounding the root system, are known to have beneficial effects in improving the growth and stress tolerance of plants. However, most bacteria in natural environments, especially those in rhizosphere soils, are recalcitrant to cultivation using traditional techniques, and thus their roles in soil health and plant growth remain unexplored. Hence, investigating new culture media and culture conditions to bring “not-yet-cultured” species into cultivation and to identify new functions is still an important task for all microbiologists. To this end, we describe improved cultivation protocols that increase the number and diversity of cultured bacteria from the rhizosphere of wheat plants. Using such approaches will lead to new insights into culturing more beneficial bacteria that live in the plant rhizosphere, in so doing creating greater opportunities not only for field application but also for promoting sustainability.
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18
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Iquebal MA, Passari AK, Jagannadham J, Ahmad F, Leo VV, Singh G, Jaiswal S, Rai A, Kumar D, Singh BP. Microbiome of Pukzing Cave in India shows high antimicrobial activity against plant and animal pathogens. Genomics 2021; 113:4098-4108. [PMID: 34699904 DOI: 10.1016/j.ygeno.2021.10.004] [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: 06/07/2021] [Revised: 09/27/2021] [Accepted: 10/05/2021] [Indexed: 10/20/2022]
Abstract
Pukzing cave, the largest cave of Mizoram, India was explored for bacterial diversity. Culture dependent method revealed 235 bacterial isolates using three different treatments. Identity of the microbial species was confirmed by 16S rDNA sequencing. The highest bacterial population was recovered from heat treatment (n = 97;41.2%) followed by normal (n = 79;33.6%) and cold treatment (n = 59;25.1%) indicating dominance of moderate thermophiles. Antimicrobial potential of isolates showed 20.4% isolates having antimicrobial ability against tested pathogens. Amplicon sequencing of PKSI, PKSII and NRP specific genes revealed presence of AMP genes in the microbial population. Six microbial pathogens were selected for screening as they are well known for different disease cause organism in various fields such as agriculture and human health. Cave environment harbors unique microbial flora and hypervariable region V4 is more informative. Higher activity of AMP assay against these microbes indicates that cave microbial communities could be potential source of future genomic resources.
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Affiliation(s)
- M A Iquebal
- Centre for Agricultural Bioinformatics, ICAR-Indian Agricultural Statistics Research Institute, New Delhi, India
| | - Ajit Kumar Passari
- Department of Biotechnology, Aizawl, Mizoram University, Mizoram, India; Departamento de Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México (UNAM), Mexico 04510, Mexico
| | - Jaisri Jagannadham
- Centre for Agricultural Bioinformatics, ICAR-Indian Agricultural Statistics Research Institute, New Delhi, India
| | - Farzana Ahmad
- Department of Biotechnology, Aizawl, Mizoram University, Mizoram, India
| | | | - Garima Singh
- Department of Botany, Pachhunga University College, Mizoram University, Aizawl 796001, Mizoram, India
| | - Sarika Jaiswal
- Centre for Agricultural Bioinformatics, ICAR-Indian Agricultural Statistics Research Institute, New Delhi, India
| | - Anil Rai
- Centre for Agricultural Bioinformatics, ICAR-Indian Agricultural Statistics Research Institute, New Delhi, India
| | - Dinesh Kumar
- Centre for Agricultural Bioinformatics, ICAR-Indian Agricultural Statistics Research Institute, New Delhi, India.
| | - Bhim Pratap Singh
- Department of Biotechnology, Aizawl, Mizoram University, Mizoram, India; Department of Agriculture and Environmental Sciences, National Institute of Food Technology Entrepreneurship and Management (NIFTEM), Kundli, Sonipat 131028, Haryana, India.
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19
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Jaroszewicz W, Bielańska P, Lubomska D, Kosznik-Kwaśnicka K, Golec P, Grabowski Ł, Wieczerzak E, Dróżdż W, Gaffke L, Pierzynowska K, Węgrzyn G, Węgrzyn A. Antibacterial, Antifungal and Anticancer Activities of Compounds Produced by Newly Isolated Streptomyces Strains from the Szczelina Chochołowska Cave (Tatra Mountains, Poland). Antibiotics (Basel) 2021; 10:antibiotics10101212. [PMID: 34680793 PMCID: PMC8532742 DOI: 10.3390/antibiotics10101212] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2021] [Revised: 10/02/2021] [Accepted: 10/03/2021] [Indexed: 12/21/2022] Open
Abstract
Resistance of bacteria, fungi and cancer cells to antibiotics and other drugs is recognized as one of the major problems in current medicine. Therefore, a search for new biologically active compounds able to either kill pathogenic cells or inhibit their growth is mandatory. Hard-to-reach habitats appear to be unexplored sources of microorganisms producing previously unknown antibiotics and other molecules revealing potentially therapeutic properties. Caves belong to such habitats, and Actinobacteria are a predominant group of microorganisms occurring there. This group of bacteria are known for production of many antibiotics and other bioactive compounds. Interestingly, it was demonstrated previously that infection with bacteriophages might enhance production of antibiotics by them. Here, we describe a series of newly isolated strains of Actinobacteria that were found in caves from the Tatra Mountains (Poland). Phage induction tests indicated that some of them may bear active prophages able to produce virions upon treatment with mitomycin C or UV irradiation. Among all the examined bacteria, two newly isolated Streptomyces sp. strains were further characterized to demonstrate their ability to inhibit the growth of pathogenic bacteria (strains of Staphylococcus aureus, Salmonella enterica, Enterococcus sp., Escherichia coli, and Pseudomonas aeruginosa) and fungi (different species and strains from the genus Candida). Moreover, extracts from these Streptomyces strains reduced viability of the breast-cancer cell line T47D. Chemical analyses of these extracts indicated the presence of isomers of dichloranthrabenzoxocinone and 4,10- or 10,12-dichloro-3-O-methylanthrabenzoxocinone, which are putative antimicrobial compounds. Moreover, various previously unknown (unclassified) molecules were also detected using liquid chromatography-mass spectrometry, suggesting that tested Streptomyces strains may synthesize a battery of bioactive compounds with antibacterial, antifungal, and anticancer activities. These results indicate that further studies on the newly isolated Actinobacteria might be a promising approach to develop novel antibacterial, antifungal, and/or anticancer drugs.
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Affiliation(s)
- Weronika Jaroszewicz
- Department of Molecular Biology, Faculty of Biology, University of Gdansk, Wita Stwosza 59, 80-308 Gdansk, Poland; (W.J.); (P.B.); (D.L.); (W.D.); (L.G.); (K.P.); (G.W.)
| | - Patrycja Bielańska
- Department of Molecular Biology, Faculty of Biology, University of Gdansk, Wita Stwosza 59, 80-308 Gdansk, Poland; (W.J.); (P.B.); (D.L.); (W.D.); (L.G.); (K.P.); (G.W.)
| | - Daria Lubomska
- Department of Molecular Biology, Faculty of Biology, University of Gdansk, Wita Stwosza 59, 80-308 Gdansk, Poland; (W.J.); (P.B.); (D.L.); (W.D.); (L.G.); (K.P.); (G.W.)
| | - Katarzyna Kosznik-Kwaśnicka
- Laboratory of Phage Therapy, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Kładki 24, 80-822 Gdansk, Poland; (K.K.-K.); (Ł.G.)
| | - Piotr Golec
- Department of Molecular Virology, Institute of Microbiology, Faculty of Biology, University of Warsaw, Miecznikowa 1, 02-096 Warsaw, Poland;
| | - Łukasz Grabowski
- Laboratory of Phage Therapy, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Kładki 24, 80-822 Gdansk, Poland; (K.K.-K.); (Ł.G.)
| | - Ewa Wieczerzak
- Department of Biomedical Chemistry, Faculty of Chemistry, University of Gdansk, Wita Stwosza 63, 80-308 Gdansk, Poland;
| | - Weronika Dróżdż
- Department of Molecular Biology, Faculty of Biology, University of Gdansk, Wita Stwosza 59, 80-308 Gdansk, Poland; (W.J.); (P.B.); (D.L.); (W.D.); (L.G.); (K.P.); (G.W.)
- Laboratory of Phage Therapy, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Kładki 24, 80-822 Gdansk, Poland; (K.K.-K.); (Ł.G.)
- Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387 Krakow, Poland
| | - Lidia Gaffke
- Department of Molecular Biology, Faculty of Biology, University of Gdansk, Wita Stwosza 59, 80-308 Gdansk, Poland; (W.J.); (P.B.); (D.L.); (W.D.); (L.G.); (K.P.); (G.W.)
| | - Karolina Pierzynowska
- Department of Molecular Biology, Faculty of Biology, University of Gdansk, Wita Stwosza 59, 80-308 Gdansk, Poland; (W.J.); (P.B.); (D.L.); (W.D.); (L.G.); (K.P.); (G.W.)
| | - Grzegorz Węgrzyn
- Department of Molecular Biology, Faculty of Biology, University of Gdansk, Wita Stwosza 59, 80-308 Gdansk, Poland; (W.J.); (P.B.); (D.L.); (W.D.); (L.G.); (K.P.); (G.W.)
| | - Alicja Węgrzyn
- Laboratory of Phage Therapy, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Kładki 24, 80-822 Gdansk, Poland; (K.K.-K.); (Ł.G.)
- Correspondence: ; Tel.: +48-58-523-6024
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Undabarrena A, Pereira CF, Kruasuwan W, Parra J, Sélem-Mojica N, Vind K, Schniete JK. Integrating perspectives in actinomycete research: an ActinoBase review of 2020-21. MICROBIOLOGY (READING, ENGLAND) 2021; 167:001084. [PMID: 34515628 PMCID: PMC8549240 DOI: 10.1099/mic.0.001084] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Accepted: 07/26/2021] [Indexed: 12/12/2022]
Abstract
Last year ActinoBase, a Wiki-style initiative supported by the UK Microbiology Society, published a review highlighting the research of particular interest to the actinomycete community. Here, we present the second ActinoBase review showcasing selected reports published in 2020 and early 2021, integrating perspectives in the actinomycete field. Actinomycetes are well-known for their unsurpassed ability to produce specialised metabolites, of which many are used as therapeutic agents with antibacterial, antifungal, or immunosuppressive activities. Much research is carried out to understand the purpose of these metabolites in the environment, either within communities or in host interactions. Moreover, many efforts have been placed in developing computational tools to handle big data, simplify experimental design, and find new biosynthetic gene cluster prioritisation strategies. Alongside, synthetic biology has provided advances in tools to elucidate the biosynthesis of these metabolites. Additionally, there are still mysteries to be uncovered in understanding the fundamentals of filamentous actinomycetes' developmental cycle and regulation of their metabolism. This review focuses on research using integrative methodologies and approaches to understand the bigger picture of actinomycete biology, covering four research areas: i) technology and methodology; ii) specialised metabolites; iii) development and regulation; and iv) ecology and host interactions.
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Affiliation(s)
- Agustina Undabarrena
- Laboratorio de Microbiología Molecular y Biotecnología Ambiental, Departamento de Química & Centro de Biotecnología Daniel Alkalay Lowitt, Universidad Técnica Federico Santa María, Valparaíso 2340000, Chile
| | - Camila F Pereira
- School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil
| | - Worarat Kruasuwan
- Microbial Cell Factory Research Team, National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, 113 Thailand Science Park, Khlong Nueng, Khlong Luang, Pathum Thani 12120, Thailand
| | - Jonathan Parra
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, G4 0RE, UK
| | - Nelly Sélem-Mojica
- Centro de Ciencias Matemáticas, Antigua Carretera a Pátzcuaro # 8701, Col. Ex Hacienda San José de la Huerta, Morelia C.P. 58089, Michoacán, México
| | - Kristiina Vind
- NAICONS Srl, Viale Ortles 22/4, 20139 Milan (MI), Italy
- Host-Microbe Interactomics Group, Wageningen University, De Elst 1 6708 WD, Wageningen, Netherlands
| | - Jana K. Schniete
- Biology, Edge Hill University, St Helens Road, Ormskirk, L39 4QP, UK
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21
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Wang Y, Shi J, Tang L, Zhang Y, Zhang Y, Wang X, Zhang X. Evaluation of Rpf protein of Micrococcus luteus for cultivation of soil actinobacteria. Syst Appl Microbiol 2021; 44:126234. [PMID: 34343788 DOI: 10.1016/j.syapm.2021.126234] [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: 05/03/2021] [Revised: 07/09/2021] [Accepted: 07/09/2021] [Indexed: 12/13/2022]
Abstract
Rpf protein, a kind of resuscitation promoting factor, was first found in the culture supernatant of Micrococcus luteus. It can resuscitate the growth of M. luteus in "viable but non-culture, VBNC" state and promote the growth of Gram-positive bacteria with high G + C content. This paper investigates the resuscitating activity of M. luteus ACCC 41016T Rpf protein, which was heterologously expressed in E. coli, to cells of M. luteus ACCC 41016T and Rhodococcus marinonascens HBUM200062 in VBNC state, and examines the effect on the cultivation of actinobacteria in soil. The results showed that the recombinant Rpf protein had resuscitation effect on M. luteus ACCC 41016T and R. marinonascens HBUM200062 in VBNC state. 83 strains of actinobacteria, which were distributed in 9 families and 12 genera, were isolated from the experimental group with recombinant Rpf protein in the culture medium. A total of 41 strains of bacteria, which were distributed in 8 families and 9 genera, were isolated from the control group without Rpf protein. The experimental group showed richer species diversity than the control group. Two rare actinobacteria, namely HBUM206391T and HBUM206404T, were obtained in the experimental group supplemented with Rpf protein. Both may be potential new species of Actinomadura and Actinokineospora, indicating that the recombinant expression of M. luteus ACCC 41016T Rpf protein can effectively promote the isolation and culture of actinobacteria in soil.
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Affiliation(s)
- Yuhui Wang
- College of Life Science, Institute of Life Science and Green Development, Hebei University, Key Laboratory of Microbial Diversity Research and Application of Hebei Province, Engineering Laboratory of Microbial Breeding and Preservation of Hebei Province, Key Laboratory of Medicinal Chemistry and Molecular Diagnosis, Ministry of Education, Baoding 071002, PR China
| | - Jiangli Shi
- College of Life Science, Institute of Life Science and Green Development, Hebei University, Key Laboratory of Microbial Diversity Research and Application of Hebei Province, Engineering Laboratory of Microbial Breeding and Preservation of Hebei Province, Key Laboratory of Medicinal Chemistry and Molecular Diagnosis, Ministry of Education, Baoding 071002, PR China
| | - Lingjie Tang
- College of Life Science, Institute of Life Science and Green Development, Hebei University, Key Laboratory of Microbial Diversity Research and Application of Hebei Province, Engineering Laboratory of Microbial Breeding and Preservation of Hebei Province, Key Laboratory of Medicinal Chemistry and Molecular Diagnosis, Ministry of Education, Baoding 071002, PR China
| | - Yufan Zhang
- College of Life Science, Institute of Life Science and Green Development, Hebei University, Key Laboratory of Microbial Diversity Research and Application of Hebei Province, Engineering Laboratory of Microbial Breeding and Preservation of Hebei Province, Key Laboratory of Medicinal Chemistry and Molecular Diagnosis, Ministry of Education, Baoding 071002, PR China
| | - Yujia Zhang
- College of Life Science, Institute of Life Science and Green Development, Hebei University, Key Laboratory of Microbial Diversity Research and Application of Hebei Province, Engineering Laboratory of Microbial Breeding and Preservation of Hebei Province, Key Laboratory of Medicinal Chemistry and Molecular Diagnosis, Ministry of Education, Baoding 071002, PR China
| | - Xinyu Wang
- College of Life Science, Institute of Life Science and Green Development, Hebei University, Key Laboratory of Microbial Diversity Research and Application of Hebei Province, Engineering Laboratory of Microbial Breeding and Preservation of Hebei Province, Key Laboratory of Medicinal Chemistry and Molecular Diagnosis, Ministry of Education, Baoding 071002, PR China
| | - Xiumin Zhang
- College of Life Science, Institute of Life Science and Green Development, Hebei University, Key Laboratory of Microbial Diversity Research and Application of Hebei Province, Engineering Laboratory of Microbial Breeding and Preservation of Hebei Province, Key Laboratory of Medicinal Chemistry and Molecular Diagnosis, Ministry of Education, Baoding 071002, PR China.
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Kim MS, Kim HR, Jeong DE, Choi SK. Cytosine Base Editor-Mediated Multiplex Genome Editing to Accelerate Discovery of Novel Antibiotics in Bacillus subtilis and Paenibacillus polymyxa. Front Microbiol 2021; 12:691839. [PMID: 34122396 PMCID: PMC8193733 DOI: 10.3389/fmicb.2021.691839] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Accepted: 04/30/2021] [Indexed: 12/30/2022] Open
Abstract
Genome-based identification of new antibiotics is emerging as an alternative to traditional methods. However, uncovering hidden antibiotics under the background of known antibiotics remains a challenge. To over this problem using a quick and effective genetic approach, we developed a multiplex genome editing system using a cytosine base editor (CBE). The CBE system achieved simultaneous double, triple, quadruple, and quintuple gene editing with efficiencies of 100, 100, 83, and 75%, respectively, as well as the 100% editing efficiency of single targets in Bacillus subtilis. Whole-genome sequencing of the edited strains showed that they had an average of 8.5 off-target single-nucleotide variants at gRNA-independent positions. The CBE system was used to simultaneously knockout five known antibiotic biosynthetic gene clusters to leave only an uncharacterized polyketide biosynthetic gene cluster in Paenibacillus polymyxa E681. The polyketide showed antimicrobial activities against gram-positive bacteria, but not gram-negative bacteria and fungi. Therefore, our findings suggested that the CBE system might serve as a powerful tool for multiplex genome editing and greatly accelerating the unraveling of hidden antibiotics in Bacillus and Paenibacillus species.
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Affiliation(s)
- Man Su Kim
- Infectious Disease Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, South Korea.,Department of Biosystems and Bioengineering, KRIBB School of Biotechnology, University of Science and Technology (UST), Daejeon, South Korea
| | - Ha-Rim Kim
- Infectious Disease Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, South Korea
| | - Da-Eun Jeong
- Infectious Disease Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, South Korea
| | - Soo-Keun Choi
- Infectious Disease Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, South Korea.,Department of Biosystems and Bioengineering, KRIBB School of Biotechnology, University of Science and Technology (UST), Daejeon, South Korea
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23
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Hui MLY, Tan LTH, Letchumanan V, He YW, Fang CM, Chan KG, Law JWF, Lee LH. The Extremophilic Actinobacteria: From Microbes to Medicine. Antibiotics (Basel) 2021; 10:682. [PMID: 34201133 PMCID: PMC8230038 DOI: 10.3390/antibiotics10060682] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 05/31/2021] [Accepted: 06/03/2021] [Indexed: 12/24/2022] Open
Abstract
Actinobacteria constitute prolific sources of novel and vital bioactive metabolites for pharmaceutical utilization. In recent years, research has focused on exploring actinobacteria that thrive in extreme conditions to unearth their beneficial bioactive compounds for natural product drug discovery. Natural products have a significant role in resolving public health issues such as antibiotic resistance and cancer. The breakthrough of new technologies has overcome the difficulties in sampling and culturing extremophiles, leading to the outpouring of more studies on actinobacteria from extreme environments. This review focuses on the diversity and bioactive potentials/medically relevant biomolecules of extremophilic actinobacteria found from various unique and extreme niches. Actinobacteria possess an excellent capability to produce various enzymes and secondary metabolites to combat harsh conditions. In particular, a few strains have displayed substantial antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA), shedding light on the development of MRSA-sensitive antibiotics. Several strains exhibited other prominent bioactivities such as antifungal, anti-HIV, anticancer, and anti-inflammation. By providing an overview of the recently found extremophilic actinobacteria and their important metabolites, we hope to enhance the understanding of their potential for the medical world.
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Affiliation(s)
- Martha Lok-Yung Hui
- Novel Bacteria and Drug Discovery Research Group (NBDD), Microbiome and Bioresource Research Strength (MBRS), Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Bandar Sunway 47500, Malaysia; (M.L.-Y.H.); (L.T.-H.T.); (V.L.)
| | - Loh Teng-Hern Tan
- Novel Bacteria and Drug Discovery Research Group (NBDD), Microbiome and Bioresource Research Strength (MBRS), Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Bandar Sunway 47500, Malaysia; (M.L.-Y.H.); (L.T.-H.T.); (V.L.)
- Clinical School Johor Bahru, Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Johor Bahru 80100, Malaysia
| | - Vengadesh Letchumanan
- Novel Bacteria and Drug Discovery Research Group (NBDD), Microbiome and Bioresource Research Strength (MBRS), Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Bandar Sunway 47500, Malaysia; (M.L.-Y.H.); (L.T.-H.T.); (V.L.)
| | - Ya-Wen He
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200030, China;
| | - Chee-Mun Fang
- Division of Biomedical Sciences, School of Pharmacy, University of Nottingham Malaysia, Semenyih, Selangor 43500, Malaysia;
| | - Kok-Gan Chan
- Division of Genetics and Molecular Biology, Institute of Biological Sciences, Faculty of Science, University of Malaya, Kuala Lumpur 50603, Malaysia
- International Genome Centre, Jiangsu University, Zhenjiang 212013, China
- Faculty of Applied Sciences, UCSI University, Kuala Lumpur 50600, Malaysia
| | - Jodi Woan-Fei Law
- Novel Bacteria and Drug Discovery Research Group (NBDD), Microbiome and Bioresource Research Strength (MBRS), Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Bandar Sunway 47500, Malaysia; (M.L.-Y.H.); (L.T.-H.T.); (V.L.)
| | - Learn-Han Lee
- Novel Bacteria and Drug Discovery Research Group (NBDD), Microbiome and Bioresource Research Strength (MBRS), Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Bandar Sunway 47500, Malaysia; (M.L.-Y.H.); (L.T.-H.T.); (V.L.)
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Park CJ, Caimi NA, Buecher DC, Valdez EW, Northup DE, Andam CP. Unexpected genomic, biosynthetic and species diversity of Streptomyces bacteria from bats in Arizona and New Mexico, USA. BMC Genomics 2021; 22:247. [PMID: 33827425 PMCID: PMC8028829 DOI: 10.1186/s12864-021-07546-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 03/19/2021] [Indexed: 11/10/2022] Open
Abstract
Background Antibiotic-producing Streptomyces bacteria are ubiquitous in nature, yet most studies of its diversity have focused on free-living strains inhabiting diverse soil environments and those in symbiotic relationship with invertebrates. Results We studied the draft genomes of 73 Streptomyces isolates sampled from the skin (wing and tail membranes) and fur surfaces of bats collected in Arizona and New Mexico. We uncovered large genomic variation and biosynthetic potential, even among closely related strains. The isolates, which were initially identified as three distinct species based on sequence variation in the 16S rRNA locus, could be distinguished as 41 different species based on genome-wide average nucleotide identity. Of the 32 biosynthetic gene cluster (BGC) classes detected, non-ribosomal peptide synthetases, siderophores, and terpenes were present in all genomes. On average, Streptomyces genomes carried 14 distinct classes of BGCs (range = 9–20). Results also revealed large inter- and intra-species variation in gene content (single nucleotide polymorphisms, accessory genes and singletons) and BGCs, further contributing to the overall genetic diversity present in bat-associated Streptomyces. Finally, we show that genome-wide recombination has partly contributed to the large genomic variation among strains of the same species. Conclusions Our study provides an initial genomic assessment of bat-associated Streptomyces that will be critical to prioritizing those strains with the greatest ability to produce novel antibiotics. It also highlights the need to recognize within-species variation as an important factor in genetic manipulation studies, diversity estimates and drug discovery efforts in Streptomyces. Supplementary Information The online version contains supplementary material available at 10.1186/s12864-021-07546-w.
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Affiliation(s)
- Cooper J Park
- Department of Molecular, Cellular and Biomedical Sciences, University of New Hampshire, Durham, NH, USA
| | - Nicole A Caimi
- Department of Biology, University of New Mexico, Albuquerque, NM, USA
| | | | - Ernest W Valdez
- Department of Biology, University of New Mexico, Albuquerque, NM, USA.,U.S. Geological Survey, Fort Collins Science Center, Fort Collins, CO, USA
| | - Diana E Northup
- Department of Biology, University of New Mexico, Albuquerque, NM, USA.
| | - Cheryl P Andam
- Department of Biological Sciences, University at Albany, State University of New York, Albany, NY, USA.
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25
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Morse KV, Richardson DR, Brown TL, Vangundy RD, Cahoon AB. Longitudinal metabarcode analysis of karst bacterioplankton microbiomes provide evidence of epikarst to cave transport and community succession. PeerJ 2021; 9:e10757. [PMID: 33732542 PMCID: PMC7950216 DOI: 10.7717/peerj.10757] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Accepted: 12/21/2020] [Indexed: 01/04/2023] Open
Abstract
Caves are often assumed to be static environments separated from weather changes experienced on the surface. The high humidity and stability of these subterranean environments make them attractive to many different organisms including microbes such as bacteria and protists. Cave waters generally originate from the surface, may be filtered by overlying soils, can accumulate in interstitial epikarst zones underground, and emerge in caves as streams, pools and droplets on speleothems. Water movement is the primary architect of karst caves, and depending on the hydrologic connectivity between surface and subsurface, is the most likely medium for the introduction of microbes to caves. Recently published metabarcoding surveys of karst cave soils and speleothems have suggested that the vast majority of bacteria residing in these habitats do not occur on the surface, calling into question the role of microbial transport by surface waters. The purpose of this study was to use metabarcoding to monitor the aquatic prokaryotic microbiome of a cave for 1 year, conduct longitudinal analyses of the cave's aquatic bacterioplankton, and compare it to nearby surface water. Water samples were collected from two locations inside Panel Cave in Natural Tunnel State Park in Duffield, VA and two locations outside of the cave. Of the two cave locations, one was fed by groundwater and drip water and the other by infiltrating surface water. A total of 1,854 distinct prokaryotic ASVs were detected from cave samples and 245 (13.1%) were not found in surface samples. PCo analysis demonstrated a marginal delineation between two cave sample sites and between cave and surface microbiomes suggesting the aquatic bacterioplankton in a karst cave is much more similar to surface microbes than reported from speleothems and soils. Most surprisingly, there was a cave microbe population and diversity bloom in the fall months whereas biodiversity remained relatively steady on the surface. The cave microbiome was more similar to the surface before the bloom than during and afterwards. This event demonstrates that large influxes of bacteria and particulate organic matter can enter the cave from either the surface or interstitial zones and the divergence of the cave microbiome from the surface demonstrates movement of microbes from the epikarst zones into the cave.
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Bacteria and Metabolic Potential in Karst Caves Revealed by Intensive Bacterial Cultivation and Genome Assembly. Appl Environ Microbiol 2021; 87:AEM.02440-20. [PMID: 33452024 DOI: 10.1128/aem.02440-20] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Accepted: 01/05/2021] [Indexed: 12/26/2022] Open
Abstract
Karst caves are widely distributed subsurface systems, and the microbiomes therein are proposed to be the driving force for cave evolution and biogeochemical cycling. In past years, culture-independent studies on the microbiomes of cave systems have been conducted, yet intensive microbial cultivation is still needed to validate the sequence-derived hypothesis and to disclose the microbial functions in cave ecosystems. In this study, the microbiomes of two karst caves in Guizhou Province in southwest China were examined. A total of 3,562 bacterial strains were cultivated from rock, water, and sediment samples, and 329 species (including 14 newly described species) of 102 genera were found. We created a cave bacterial genome collection of 218 bacterial genomes from a karst cave microbiome through the extraction of 204 database-derived genomes and de novo sequencing of 14 new bacterial genomes. The cultivated genome collection obtained in this study and the metagenome data from previous studies were used to investigate the bacterial metabolism and potential involvement in the carbon, nitrogen, and sulfur biogeochemical cycles in the cave ecosystem. New N2-fixing Azospirillum and alkane-oxidizing Oleomonas species were documented in the karst cave microbiome. Two pcaIJ clusters of the β-ketoadipate pathway that were abundant in both the cultivated microbiomes and the metagenomic data were identified, and their representatives from the cultivated bacterial genomes were functionally demonstrated. This large-scale cultivation of a cave microbiome represents the most intensive collection of cave bacterial resources to date and provides valuable information and diverse microbial resources for future cave biogeochemical research.IMPORTANCE Karst caves are oligotrophic environments that are dark and humid and have a relatively stable annual temperature. The diversity of bacteria and their metabolisms are crucial for understanding the biogeochemical cycling in cave ecosystems. We integrated large-scale bacterial cultivation with metagenomic data mining to explore the compositions and metabolisms of the microbiomes in two karst cave systems. Our results reveal the presence of a highly diversified cave bacterial community, and 14 new bacterial species were described and their genomes sequenced. In this study, we obtained the most intensive collection of cultivated microbial resources from karst caves to date and predicted the various important routes for the biogeochemical cycling of elements in cave ecosystems.
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Lukoseviciute L, Lebedeva J, Kuisiene N. Diversity of Polyketide Synthases and Nonribosomal Peptide Synthetases Revealed Through Metagenomic Analysis of a Deep Oligotrophic Cave. MICROBIAL ECOLOGY 2021; 81:110-121. [PMID: 32638044 DOI: 10.1007/s00248-020-01554-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Accepted: 07/01/2020] [Indexed: 06/11/2023]
Abstract
Caves are considered to be extreme and challenging environments. It is believed that the ability of microorganisms to produce secondary metabolites enhances their survivability and adaptiveness in the energy-starved cave environment. Unfortunately, information on the genetic potential for the production of secondary metabolites, such as polyketides and nonribosomal peptides, is limited. In the present study, we aimed to identify and characterize genes responsible for the production of secondary metabolites in the microbial community of one of the deepest caves in the world, Krubera-Voronja Cave (43.4184 N 40.3083 E, Western Caucasus). The analysed sample materials included sediments, drinkable water from underground camps, soil and clay from the cave walls, speleothems and coloured spots from the cave walls. The type II polyketide synthases (PKSs) ketosynthases α and β and the adenylation domains of nonribosomal peptide synthetases (NRPSs) were investigated using a metagenomic approach. Taxonomic diversity analysis showed that most PKS sequences could be attributed to Actinobacteria followed by unclassified bacteria and Acidobacteria, while the NRPS sequences were more taxonomically diverse and could be assigned to Proteobacteria, Actinobacteria, Cyanobacteria, Firmicutes, Chloroflexi, etc. Only three putative metabolites could be predicted: an angucycline group polyketide, a massetolide A-like cyclic lipopeptide and a surfactin-like lipopeptide. The absolute majority of PKS and NRPS sequences showed low similarity with the sequences of the reference biosynthetic pathways, suggesting that these sequences could be involved in the production of novel secondary metabolites.
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Affiliation(s)
- Laima Lukoseviciute
- Department of Microbiology and Biotechnology, Institute of Biosciences, Life Sciences Center, Vilnius University, Vilnius, Lithuania
| | - Jolanta Lebedeva
- Department of Microbiology and Biotechnology, Institute of Biosciences, Life Sciences Center, Vilnius University, Vilnius, Lithuania
| | - Nomeda Kuisiene
- Department of Microbiology and Biotechnology, Institute of Biosciences, Life Sciences Center, Vilnius University, Vilnius, Lithuania.
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Messaoudi O, Wink J, Bendahou M. Diversity of Actinobacteria Isolated from Date Palms Rhizosphere and Saline Environments: Isolation, Identification and Biological Activity Evaluation. Microorganisms 2020; 8:E1853. [PMID: 33255541 PMCID: PMC7760371 DOI: 10.3390/microorganisms8121853] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 10/30/2020] [Accepted: 11/02/2020] [Indexed: 01/20/2023] Open
Abstract
The diversity of cultural Actinobacteria in two types of Algerian Sahara environments, including saline environments and date palms rhizosphere, was investigated. In this study, a total of 40 strains of actinomycetes was isolated from different soil samples, using a rehydration and centrifugation method. Molecular identification, based on 16S rRNA gene sequence analysis, revealed that these isolates were affiliated to six clusters corresponding to eight genera, including Streptomyces, Nocardiopsis, Saccharopolyspora, Actinomadura, Actinocorallia, Micromonospora, Couchioplanes, and Planomonospora. A taxonomic analysis, based on the morphological, physiological, biochemical, and molecular investigation, of selected strains, which belong to the rare Actinobacteria, was undertaken. Four strains (CG3, A111, A93, and A79) were found to form distinct phyletic lines and represent new actinobacterial taxa. An assessment of antimicrobial proprieties of the 40 obtained actinomycetes strains, showed moderate to strong antimicrobial activities against fungi and bacteria. This study demonstrated the richness of Algerian Sahara with rare Actinobacteria, which can provide novel bioactive metabolites, to solving some of the most challenging problems of the day, such as multi-drug resistance.
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Affiliation(s)
- Omar Messaoudi
- Laboratory of Applied Microbiology in Food, Biomedical and Environment, Abou Bekr Belkaïd University, 13000 Tlemcen, Algeria;
- Department of Biology, Faculty of Science, University of Amar Telidji, 03000 Laghouat, Algeria
- Microbial Strain Collection, Helmholtz Centre for Infection Research GmbH (HZI), Inhoffenstrasse 7, 38124 Braunschweig, Germany;
| | - Joachim Wink
- Microbial Strain Collection, Helmholtz Centre for Infection Research GmbH (HZI), Inhoffenstrasse 7, 38124 Braunschweig, Germany;
| | - Mourad Bendahou
- Laboratory of Applied Microbiology in Food, Biomedical and Environment, Abou Bekr Belkaïd University, 13000 Tlemcen, Algeria;
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On the Risks of Phylogeny-Based Strain Prioritization for Drug Discovery: Streptomyces lunaelactis as a Case Study. Biomolecules 2020; 10:biom10071027. [PMID: 32664387 PMCID: PMC7408125 DOI: 10.3390/biom10071027] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2020] [Revised: 07/06/2020] [Accepted: 07/07/2020] [Indexed: 12/11/2022] Open
Abstract
Strain prioritization for drug discovery aims at excluding redundant strains of a collection in order to limit the repetitive identification of the same molecules. In this work, we wanted to estimate what can be unexploited in terms of the amount, diversity, and novelty of compounds if the search is focused on only one single representative strain of a species, taking Streptomyces lunaelactis as a model. For this purpose, we selected 18 S. lunaelactis strains taxonomically clustered with the archetype strain S. lunaelactis MM109T. Genome mining of all S. lunaelactis isolated from the same cave revealed that 54% of the 42 biosynthetic gene clusters (BGCs) are strain specific, and five BGCs are not present in the reference strain MM109T. In addition, even when a BGC is conserved in all strains such as the bag/fev cluster involved in bagremycin and ferroverdin production, the compounds produced highly differ between the strains and previously unreported compounds are not produced by the archetype MM109T. Moreover, metabolomic pattern analysis uncovered important profile heterogeneity, confirming that identical BGC predisposition between two strains does not automatically imply chemical uniformity. In conclusion, trying to avoid strain redundancy based on phylogeny and genome mining information alone can compromise the discovery of new natural products and might prevent the exploitation of the best naturally engineered producers of specific molecules.
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Mining the Biosynthetic Potential for Specialized Metabolism of a Streptomyces Soil Community. Antibiotics (Basel) 2020; 9:antibiotics9050271. [PMID: 32456220 PMCID: PMC7277575 DOI: 10.3390/antibiotics9050271] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 05/18/2020] [Accepted: 05/20/2020] [Indexed: 12/22/2022] Open
Abstract
The diversity and distribution of specialized metabolite gene clusters within a community of bacteria living in the same soil habitat are poorly documented. Here we analyzed the genomes of 8 Streptomyces isolated at micro-scale from a forest soil that belong to the same species or to different species. The results reveal high levels of diversity, with a total of 261 biosynthesis gene clusters (BGCs) encoding metabolites such as terpenes, polyketides (PKs), non-ribosomal peptides (NRPs) and ribosomally synthesized and post-translationally modified peptides (RiPPs) with potential bioactivities. A significant part of these BGCs (n = 53) were unique to only one strain when only 5 were common to all strains. The metabolites belong to very diverse chemical families and revealed that a large diversity of metabolites can potentially be produced in the community. Although that analysis of the global metabolome using GC-MS revealed that most of the metabolites were shared between the strains, they exhibited a specific metabolic pattern. We also observed that the presence of these accessory pathways might result from frequent loss and gain of genes (horizontal transfer), showing that the potential of metabolite production is a dynamic phenomenon in the community. Sampling Streptomyces at the community level constitutes a good frame to discover new biosynthetic pathways and it appears as a promising reservoir for the discovery of new bioactive compounds.
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Kato S, Terashima M, Yama A, Sato M, Kitagawa W, Kawasaki K, Kamagata Y. Improved Isolation of Uncultured Anaerobic Bacteria using Medium Prepared with Separate Sterilization of Agar and Phosphate. Microbes Environ 2020; 35. [PMID: 32009018 PMCID: PMC7104283 DOI: 10.1264/jsme2.me19060] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
We previously demonstrated that a simple modification in the preparation of agar media, i.e., autoclaving phosphate and agar separately (termed the “PS protocol”), improved the culturability of aerobic microorganisms by reducing the generation of reactive oxygen species. We herein investigated the effects of the PS protocol on the cultivation of anaerobic microorganisms using sludge from a wastewater treatment system as a microbial source. The application of the PS protocol increased colony numbers and the frequency of phylogenetically novel isolates under aerobic, nitrate reduction, and fermentation conditions. The PS protocol is useful for isolating both aerobic and anaerobic microorganisms.
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Affiliation(s)
- Souichiro Kato
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST).,Division of Applied Bioscience, Graduate School of Agriculture, Hokkaido University
| | - Mia Terashima
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST).,Institute of Low Temperature Science, Hokkaido University
| | - Ayano Yama
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST).,Hokkaido High-Technology College
| | - Megumi Sato
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST).,Hokkaido High-Technology College
| | - Wataru Kitagawa
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST).,Division of Applied Bioscience, Graduate School of Agriculture, Hokkaido University.,Computational Bio Big Data Open Innovation Laboratory (CBBD-OIL), AIST
| | - Kosei Kawasaki
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST)
| | - Yoichi Kamagata
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST).,Division of Applied Bioscience, Graduate School of Agriculture, Hokkaido University.,Bioproduction Research Institute, AIST
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32
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Genilloud O. Natural products discovery and potential for new antibiotics. Curr Opin Microbiol 2019; 51:81-87. [PMID: 31739283 DOI: 10.1016/j.mib.2019.10.012] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Accepted: 10/31/2019] [Indexed: 02/05/2023]
Abstract
Microbial natural products have been one of the most important sources for the discovery of potential new antibiotics. However, the decline in the number of new chemical scaffolds discovered and the rediscovery problem of old known molecules has become a limitation for discovery programs developed by an industry confronted by a lack of incentives and a broken economic model. In contrast, the emergence of multidrug resistance in key pathogens has continued to progress and this issue is compounded by a lack of new antibiotics in development to address most of the difficult to treat infections. Advances in genome mining have confirmed the richness of biosynthetic gene clusters (BGCs) in the majority of microbial sources, and this suggests that an untapped chemical diversity is waiting to be discovered. The development of new genome engineering and synthetic biology tools, and the implementation of comparative omic approaches is fostering the development of new integrated culture-based strategies and genomic-driven approaches aimed at delivering new chemical classes of antibiotics.
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Affiliation(s)
- Olga Genilloud
- Fundación MEDINA, Avda Conocimiento 34, 18016 Granada, Spain.
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33
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Djinni I, Defant A, Kecha M, Mancini I. Actinobacteria Derived from Algerian Ecosystems as a Prominent Source of Antimicrobial Molecules. Antibiotics (Basel) 2019; 8:E172. [PMID: 31581466 PMCID: PMC6963827 DOI: 10.3390/antibiotics8040172] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 09/25/2019] [Accepted: 09/25/2019] [Indexed: 01/19/2023] Open
Abstract
Actinobacteria, in particular "rare actinobacteria" isolated from extreme ecosystems, remain the most inexhaustible source of novel antimicrobials, offering a chance to discover new bioactive metabolites. This is the first overview on actinobacteria isolated in Algeria since 2002 to date with the aim to present their potential in producing bioactive secondary metabolites. Twenty-nine new species and one novel genus have been isolated, mainly from the Saharan soil and palm groves, where 37.93% of the most abundant genera belong to Saccharothrix and Actinopolyspora. Several of these strains were found to produce antibiotics and antifungal metabolites, including 17 new molecules among the 50 structures reported, and some of these antibacterial metabolites have shown interesting antitumor activities. A series of approaches used to enhance the production of bioactive compounds is also presented as the manipulation of culture media by both classical methods and modeling designs through statistical strategies and the associations with diverse organisms and strains. Focusing on the Algerian natural sources of antimicrobial metabolites, this work is a representative example of the potential of a closely combined study on biology and chemistry of natural products.
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Affiliation(s)
- Ibtissem Djinni
- Laboratoire de Microbiologie Appliquée, Faculté des Sciences de la Nature et de la Vie, Université de Bejaia 06000, Algeria.
- Bioorganic Chemistry Laboratory, Department of Physics, University of Trento, Trento 38123, Italy.
| | - Andrea Defant
- Bioorganic Chemistry Laboratory, Department of Physics, University of Trento, Trento 38123, Italy.
| | - Mouloud Kecha
- Laboratoire de Microbiologie Appliquée, Faculté des Sciences de la Nature et de la Vie, Université de Bejaia 06000, Algeria.
| | - Ines Mancini
- Bioorganic Chemistry Laboratory, Department of Physics, University of Trento, Trento 38123, Italy.
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34
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Bukelskis D, Dabkeviciene D, Lukoseviciute L, Bucelis A, Kriaučiūnas I, Lebedeva J, Kuisiene N. Screening and Transcriptional Analysis of Polyketide Synthases and Non-ribosomal Peptide Synthetases in Bacterial Strains From Krubera-Voronja Cave. Front Microbiol 2019; 10:2149. [PMID: 31572349 PMCID: PMC6753585 DOI: 10.3389/fmicb.2019.02149] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Accepted: 09/02/2019] [Indexed: 12/25/2022] Open
Abstract
Identification of novel bioactive compounds represents an important field in modern biomedical research. Microorganisms of the underexplored environments, such as deserts, hot springs, oceans, and caves are highly promising candidates for screening such metabolites. Screening for biosynthetic genes is the most effective strategy to characterize bioactivity in a certain environment. However, knowledge is either scant or non-existent about the expression of the biosynthetic genes encoding for various bioactive compounds in the microorganisms from the caves. The aim of the current study was to screen for the genes of polyketide synthases and non-ribosomal peptide synthetases in Krubera–Voronja Cave (43.4184 N 40.3083 E, Western Caucasus) bacterial isolates as well as to evaluate the expression of these genes under laboratory conditions. In total, 91 bacterial strains isolated from the cave were screened for the presence of polyketide synthase and non-ribosomal peptide synthetase genes. Phenotypically inactive strains were the main focus (the test group) of our study, while the strains with the identified antibacterial activity served as the control group. Our PCR-based screening clearly showed that the majority of the strains harbored at least one biosynthetic gene. Prediction of the putative products allowed us to identify bioactive compounds with antibacterial, anticancer, antifungal, anti-inflammatory, antimycoplasmic, antiviral, insecticidal, and thrombolytic activity. For most polyketide synthases and non-ribosomal peptide synthetases, putative products could not be predicted; they are unknown. Qualitative transcriptional analysis did not show substantial differences between the test group and the control group of the strains. One to four biosynthetic genes were constitutively expressed in all the tested strains, irrespective of the group. Quantitative transcriptional analysis of the constitutively expressed biosynthetic genes demonstrated that the expression of a particular gene could be affected by both the amount of the nutrients in the culture medium and the growth phase.
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Affiliation(s)
- Dominykas Bukelskis
- Institute of Biosciences, Department of Microbiology and Biotechnology, Life Sciences Center, Vilnius University, Vilnius, Lithuania
| | - Daiva Dabkeviciene
- Institute of Biosciences, Department of Biochemistry and Molecular Biology, Life Sciences Center, Vilnius University, Vilnius, Lithuania
| | - Laima Lukoseviciute
- Institute of Biosciences, Department of Microbiology and Biotechnology, Life Sciences Center, Vilnius University, Vilnius, Lithuania
| | - Airidas Bucelis
- Institute of Biosciences, Department of Microbiology and Biotechnology, Life Sciences Center, Vilnius University, Vilnius, Lithuania
| | - Ignas Kriaučiūnas
- Institute of Biosciences, Department of Microbiology and Biotechnology, Life Sciences Center, Vilnius University, Vilnius, Lithuania
| | - Jolanta Lebedeva
- Institute of Biosciences, Department of Microbiology and Biotechnology, Life Sciences Center, Vilnius University, Vilnius, Lithuania
| | - Nomeda Kuisiene
- Institute of Biosciences, Department of Microbiology and Biotechnology, Life Sciences Center, Vilnius University, Vilnius, Lithuania
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35
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A Single Biosynthetic Gene Cluster Is Responsible for the Production of Bagremycin Antibiotics and Ferroverdin Iron Chelators. mBio 2019; 10:mBio.01230-19. [PMID: 31409675 PMCID: PMC6692506 DOI: 10.1128/mbio.01230-19] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Access to whole-genome sequences has exposed the general incidence of the so-called cryptic biosynthetic gene clusters (BGCs), thereby renewing their interest for natural product discovery. As a consequence, genome mining is the often first approach implemented to assess the potential of a microorganism for producing novel bioactive metabolites. By revealing a new level of complexity of natural product biosynthesis, we further illustrate the difficulty of estimation of the panel of molecules associated with a BGC based on genomic information alone. Indeed, we found that the same gene cluster is responsible for the production of compounds which differ in terms of structure and bioactivity. The production of these different compounds responds to different environmental triggers, which suggests that multiplication of culture conditions is essential for revealing the entire panel of molecules made by a single BGC. Biosynthetic gene clusters (BGCs) are organized groups of genes involved in the production of specialized metabolites. Typically, one BGC is responsible for the production of one or several similar compounds with bioactivities that usually only vary in terms of strength and/or specificity. Here we show that the previously described ferroverdins and bagremycins, which are families of metabolites with different bioactivities, are produced from the same BGC, whereby the fate of the biosynthetic pathway depends on iron availability. Under conditions of iron depletion, the monomeric bagremycins are formed, representing amino-aromatic antibiotics resulting from the condensation of 3-amino-4-hydroxybenzoic acid with p-vinylphenol. Conversely, when iron is abundantly available, the biosynthetic pathway additionally produces a molecule based on p-vinylphenyl-3-nitroso-4-hydroxybenzoate, which complexes iron to form the trimeric ferroverdins that have anticholesterol activity. Thus, our work shows a unique exception to the concept that BGCs should only produce a single family of molecules with one type of bioactivity and that in fact different bioactive molecules may be produced depending on the environmental conditions.
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36
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Zhu HZ, Zhang ZF, Zhou N, Jiang CY, Wang BJ, Cai L, Liu SJ. Diversity, Distribution and Co-occurrence Patterns of Bacterial Communities in a Karst Cave System. Front Microbiol 2019; 10:1726. [PMID: 31447801 PMCID: PMC6691740 DOI: 10.3389/fmicb.2019.01726] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2019] [Accepted: 07/12/2019] [Indexed: 12/21/2022] Open
Abstract
Caves are typified by their permanent darkness and a shortage of nutrients. Consequently, bacteria play an important role in sustaining such subsurface ecosystems by dominating primary production and fueling biogeochemical cycles. China has one of the world’s largest areas of karst topography in the Yunnan-Guizhou Plateau, yet the bacteriomes in these karst caves remain unexplored. In this study, bacteriomes of eight karst caves in southwest China were examined, and co-occurrence networks of cave bacterial communities were constructed. Results revealed abundant and diversified bacterial communities in karst caves, with Proteobacteria, Actinobacteria, and Firmicutes being the most abundant phyla. Statistical analysis revealed no significant difference in bacteriomes among the eight caves. However, a PCoA plot did show that the bacterial communities of 128 cave samples clustered into groups corresponding to sampling types (air, water, rock, and sediment). These results suggest that the distribution of bacterial communities is driven more by sample types than the separate caves from which samples were collected. Further community-level composition analysis indicated that Proteobacteria were most dominant in water and air samples, while Actinobacteria dominated the sediment and rock samples. Co-occurrence analysis revealed highly modularized assembly patterns of the cave bacterial community, with Nitrosococcaceae wb1-P19, an uncultured group in Rokubacteriales, and an uncultured group in Gaiellales, being the top-three keystone members. These results not only expand our understanding of cave bacteriomes but also inspires functional exploration of bacterial strains in karst caves.
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Affiliation(s)
- Hai-Zhen Zhu
- State Key Laboratory of Microbial Resources and Environmental Microbiology Research Center at Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Zhi-Feng Zhang
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China.,State Key Laboratory of Mycology at Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Nan Zhou
- State Key Laboratory of Microbial Resources and Environmental Microbiology Research Center at Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Cheng-Ying Jiang
- State Key Laboratory of Microbial Resources and Environmental Microbiology Research Center at Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.,Research Center for Eco-Envorinmental Sciences-Institute of Microbiology, Chinese Academy of Sciences-University of Chinese Academy of Sciences, Joint-Lab of Microbial Technology for Environmental Science, Beijing, China
| | - Bao-Jun Wang
- State Key Laboratory of Microbial Resources and Environmental Microbiology Research Center at Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Lei Cai
- State Key Laboratory of Mycology at Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Shuang-Jiang Liu
- State Key Laboratory of Microbial Resources and Environmental Microbiology Research Center at Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China.,Research Center for Eco-Envorinmental Sciences-Institute of Microbiology, Chinese Academy of Sciences-University of Chinese Academy of Sciences, Joint-Lab of Microbial Technology for Environmental Science, Beijing, China.,College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, China
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37
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Mast Y, Stegmann E. Actinomycetes: The Antibiotics Producers. Antibiotics (Basel) 2019; 8:E105. [PMID: 31362405 PMCID: PMC6783997 DOI: 10.3390/antibiotics8030105] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Accepted: 07/25/2019] [Indexed: 12/20/2022] Open
Abstract
Actinomycetes are well known as an inexhaustible source for antibiotics [...].
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Affiliation(s)
- Yvonne Mast
- Department of Bioresources for Bioeconomy and Health Research, Leibniz Institute DSMZ-German Culture Collection for Microorganisms and Cell Cultures, 38124 Braunschweig, Germany.
- Institute for Microbiology, Technical University of Braunschweig, 38106 Braunschweig, Germany.
- Department of Microbiology/Biotechnology, Interfaculty Institute of Microbiology and Infection Medicine, Faculty of Science, Eberhard Karls University of Tübingen, Auf der Morgenstelle 28, D-72076 Tübingen, Germany.
- German Center for Infection Research (DZIF), Partner Site Tübingen, D-72076 Tübingen, Germany.
| | - Evi Stegmann
- Department of Microbiology/Biotechnology, Interfaculty Institute of Microbiology and Infection Medicine, Faculty of Science, Eberhard Karls University of Tübingen, Auf der Morgenstelle 28, D-72076 Tübingen, Germany.
- German Center for Infection Research (DZIF), Partner Site Tübingen, D-72076 Tübingen, Germany.
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38
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Antibacterial potential of Actinobacteria from a Limestone Mining Site in Meghalaya, India. JOURNAL OF PURE AND APPLIED MICROBIOLOGY 2019. [DOI: 10.22207/jpam.13.2.14] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
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39
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Molecular Identification of Selected Streptomyces Strains Isolated from Mexican Tropical Soils and their Anti- Candida Activity. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2019; 16:ijerph16111913. [PMID: 31151174 PMCID: PMC6603721 DOI: 10.3390/ijerph16111913] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 04/17/2019] [Accepted: 04/19/2019] [Indexed: 11/23/2022]
Abstract
The increasing incidence of Candida albicans infections and resistance to current antifungal therapies has led to the search for new and more effective antifungal compounds. Actinobacterial species from the Streptomyces genus are recognized as some of the major producers of antimicrobial compounds. Therefore, the aims of this study were: (1) the identification of Streptomyces strains isolated from Mexican tropical acidic soils, (2) the evaluation of their antifungal activity on C. albicans, and (3) the exploration of the presence of polyketide synthase genes in their genome and antifungal secondary metabolites in their extracts. Four actinobacterial strains, isolated from previously unexplored soils with antibacterial antecedents, were selected. These strains were identified as Streptomycesangustmyceticus S6A-03, Streptomyces manipurensis S3A-05 and S3A-09, and Streptomyces parvisporogenes S2A-04, according to their molecular analyses. The ethanol extract of the lyophilized supernatant of S. parvisporogenes displayed the most interesting antifungal activity against C. albicans, with a minimum inhibitory concentration (MIC) of 0.5 mg/mL. Type I polyketide synthase (PKS-I) and non-ribosomal peptide synthase (NRPS) genes were detected in all strains. In addition, type II PKS genes (PKS-II) were also found in S.manipurensis S3A-05 and S. parvisporogenes. LC-UV-HRMS analysis of the active organic extract of S. parvisporogenes indicated the presence of the known antifungal compound carbazomycin G as the major component.
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Gosse JT, Ghosh S, Sproule A, Overy D, Cheeptham N, Boddy CN. Whole Genome Sequencing and Metabolomic Study of Cave Streptomyces Isolates ICC1 and ICC4. Front Microbiol 2019; 10:1020. [PMID: 31134037 PMCID: PMC6524458 DOI: 10.3389/fmicb.2019.01020] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Accepted: 04/24/2019] [Indexed: 11/13/2022] Open
Abstract
The terrestrial subsurface microbiome has gained considerable amount of interests in the recent years because of its rich potential resource for biomining novel genes coding for metabolites possessing antimicrobial activities. In our previous study, we identified two Streptomyces isolates, designated as ICC1 and ICC4, from the Iron Curtain Cave, Chilliwack, Canada that exhibited antagonistic activities against the multidrug resistant strains of Escherichia coli. In this study, the genomes of these two isolates were sequenced by Illumina MiSeq, assembled and annotated. The genes associated with secondary metabolite production were identified and annotated using the bioinformatics platforms antiSMASH and BAGEL. ICC1 and ICC4 were then cultivated and ICC1 metabolome characterized by UHPLC-ESI-HRMS. The Global Natural Products Social Molecular Networking was used to identify metabolites based on the MS/MS spectral data. ICC1 and ICC4 showed a high level of sequence identity with the terrestrial bacteria Streptomyces lavendulae; however, they possess a greater secondary metabolite potential as estimated by the total number of identified biosynthetic gene clusters (BGCs). In particular, ICC1 and ICC4 had a greater number of polyketide and non-ribosomal peptide BGCs. The most frequently detected BGCs were those predicted to generate terpenes, small and low complexity dipeptides and lipids. Spectral analysis clearly identified a number of diketopiperazine products through matched reference spectra for cyclo (Leu-Pro), cyclo (Pro-Val) and cyclo [(4-hydroxyPro)-Leu]. One of the terpenes gene clusters predicted by antiSMASH possesses a seven-gene pathway consistent with diazepinomicin biosynthesis. This molecule contains a very rare core structure and its BGC, to date, has only been identified from a single bacterial genome. The tetrapeptide siderophore coelichelin BGC was unambiguously identified in the genome, however, the metabolite could not be identified from the culture extracts. Two type III polyketides, 2′, 5′ – dimethoxyflavone and nordentatin, were identified from the UHPLC-HRMS data of the aqueous and n-butanolic fractions of Streptomyces sp. ICC1, respectively. A BGC likely encoding these metabolites was predicted in both genomes. The predicted similarities in molecule production and genome shared by these two strains could be an indicative of a cooperative mode of living in extreme habitats instead of a competitive one. This secondary metabolite potential may contribute to the fitness of ICC1 and ICC4 in the Iron Curtain Cave.
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Affiliation(s)
- Jessica Thandara Gosse
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON, Canada
| | - Soumya Ghosh
- Department of Biological Sciences, Faculty of Science, Thompson Rivers University, Kamloops, BC, Canada
| | - Amanda Sproule
- Ottawa Research and Development Centre, Agriculture and Agri-Food Canada, Ottawa, ON, Canada
| | - David Overy
- Ottawa Research and Development Centre, Agriculture and Agri-Food Canada, Ottawa, ON, Canada
| | - Naowarat Cheeptham
- Department of Biological Sciences, Faculty of Science, Thompson Rivers University, Kamloops, BC, Canada
| | - Christopher N Boddy
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON, Canada
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41
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Rangseekaew P, Pathom-Aree W. Cave Actinobacteria as Producers of Bioactive Metabolites. Front Microbiol 2019; 10:387. [PMID: 30967844 PMCID: PMC6438885 DOI: 10.3389/fmicb.2019.00387] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Accepted: 02/13/2019] [Indexed: 11/13/2022] Open
Abstract
Recently, there is an urgent need for new drugs due to the emergence of drug resistant pathogenic microorganisms and new infectious diseases. Members of phylum Actinobacteria are promising source of bioactive compounds notably antibiotics. The search for such new compounds has shifted to extreme or underexplored environments to increase the possibility of discovery. Cave ecosystems have attracted interest of the research community because of their unique characteristics and the microbiome residing inside including actinobacteria. At the time of writing, 47 species in 30 genera of actinobacteria were reported from cave and cave related habitats. Novel and promising bioactive compounds have been isolated and characterized. This mini-review focuses on the diversity of cultivable actinobacteria in cave and cave-related environments, and their bioactive metabolites from 1999 to 2018.
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Affiliation(s)
- Pharada Rangseekaew
- Doctor of Philosophy Program in Applied Microbiology (International Program) in Faculty of Science, Chiang Mai University, Chiang Mai, Thailand.,Graduate School, Chiang Mai University, Chiang Mai, Thailand
| | - Wasu Pathom-Aree
- Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai, Thailand.,Center of Excellence in Bioresources for Agriculture, Industry and Medicine, Chiang Mai University, Chiang Mai, Thailand
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42
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Lim A, Naidenov B, Bates H, Willyerd K, Snider T, Couger MB, Chen C, Ramachandran A. Nanopore ultra-long read sequencing technology for antimicrobial resistance detection in Mannheimia haemolytica. J Microbiol Methods 2019; 159:138-147. [PMID: 30849421 DOI: 10.1016/j.mimet.2019.03.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2018] [Revised: 03/02/2019] [Accepted: 03/04/2019] [Indexed: 02/02/2023]
Abstract
Disruptive innovations in long-range, cost-effective direct template nucleic acid sequencing are transforming clinical and diagnostic medicine. A multidrug resistant strain and a pan-susceptible strain of Mannheimia haemolytica, isolated from pneumonic bovine lung samples, were sequenced at 146× and 111× coverage, respectively with Oxford Nanopore Technologies MinION. De novo assembly produced a complete genome for the non-resistant strain and a nearly complete assembly for the drug resistant strain. Functional annotation using RAST (Rapid Annotations using Subsystems Technology), CARD (Comprehensive Antibiotic Resistance Database) and ResFinder databases identified genes conferring resistance to different classes of antibiotics including β-lactams, tetracyclines, lincosamides, phenicols, aminoglycosides, sulfonamides and macrolides. Resistance phenotypes of the M. haemolytica strains were determined by minimum inhibitory concentration (MIC) of the antibiotics. Sequencing with a highly portable MinION device corresponded to MIC assays with most of the antimicrobial resistant determinants being identified with as few as 5437 reads, except for the genes responsible for resistance to Fluoroquinolones. The resulting quality assemblies and AMR gene annotation highlight the efficiency of ultra-long read, whole-genome sequencing (WGS) as a valuable tool in diagnostic veterinary medicine.
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Affiliation(s)
- Alexander Lim
- Department of Biochemistry and Molecular Biology, Oklahoma State University, 246 Noble Research Center, Stillwater, OK 74078, United States
| | - Bryan Naidenov
- Department of Biochemistry and Molecular Biology, Oklahoma State University, 246 Noble Research Center, Stillwater, OK 74078, United States
| | - Haley Bates
- Oklahoma Animal Disease Diagnostic Laboratory, Center for Veterinary Health Sciences, 1950 W. Farm Road, Stillwater, OK 74078, United States
| | - Karyn Willyerd
- Department of Biochemistry and Molecular Biology, Oklahoma State University, 246 Noble Research Center, Stillwater, OK 74078, United States
| | - Timothy Snider
- Oklahoma Animal Disease Diagnostic Laboratory, Center for Veterinary Health Sciences, 1950 W. Farm Road, Stillwater, OK 74078, United States
| | - Matthew Brian Couger
- Department of Microbiology and Molecular Genetics, Oklahoma State University, 307 Life Sciences East, Stillwater, OK 74078, United States
| | - Charles Chen
- Department of Biochemistry and Molecular Biology, Oklahoma State University, 246 Noble Research Center, Stillwater, OK 74078, United States.
| | - Akhilesh Ramachandran
- Oklahoma Animal Disease Diagnostic Laboratory, Center for Veterinary Health Sciences, 1950 W. Farm Road, Stillwater, OK 74078, United States.
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Calcite moonmilk of microbial origin in the Etruscan Tomba degli Scudi in Tarquinia, Italy. Sci Rep 2018; 8:15839. [PMID: 30367083 PMCID: PMC6203712 DOI: 10.1038/s41598-018-34134-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Accepted: 10/04/2018] [Indexed: 02/08/2023] Open
Abstract
A white deposit covering the walls in the Stanza degli Scudi of the Tomba degli Scudi, Tarquinia, Italy, has been investigated. In this chamber, which is still preserved from any kind of intervention such as cleaning and sanitization, ancient Etruscans painted shields to celebrate the military power of the Velcha family. Scanning electron microscopy analysis has revealed the presence of characteristic nanostructures corresponding to a calcite secondary mineral deposit called moonmilk. Analysis of the microbial community identified Proteobacteria, Acidobacteria and Actinobacteria as the most common phyla in strong association with the moonmilk needle fibre calcite and nanofibers of calcium carbonate. Employing classical microbiological analysis, we isolated from moonmilk a Streptomyces strain able to deposit gypsum and calcium carbonate on plates, supporting the hypothesis of an essential contribution of microorganisms to the formation of moonmilk.
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Covington BC, Spraggins JM, Ynigez-Gutierrez AE, Hylton ZB, Bachmann BO. Response of Secondary Metabolism of Hypogean Actinobacterial Genera to Chemical and Biological Stimuli. Appl Environ Microbiol 2018; 84:e01125-18. [PMID: 30030223 PMCID: PMC6146984 DOI: 10.1128/aem.01125-18] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Accepted: 07/05/2018] [Indexed: 12/24/2022] Open
Abstract
Microorganisms within microbial communities respond to environmental challenges by producing biologically active secondary metabolites, yet the majority of these small molecules remain unidentified. We have previously demonstrated that secondary metabolite biosynthesis in actinomycetes can be activated by model environmental chemical and biological stimuli, and metabolites can be identified by comparative metabolomics analyses under different stimulus conditions. Here, we surveyed the secondary metabolite productivity of a group of 20 phylogenetically diverse actinobacteria isolated from hypogean (cave) environments by applying a battery of stimuli consisting of exposure to antibiotics, metals, and mixed microbial culture. Comparative metabolomics was used to reveal secondary metabolite responses from stimuli. These analyses revealed substantial changes in global metabolomic dynamics, with over 30% of metabolomic features increasing more than 10-fold under at least one stimulus condition. Selected features were isolated and identified via nuclear magnetic resonance (NMR), revealing several known secondary metabolite families, including the tetarimycins, aloesaponarins, hypogeamicins, actinomycins, and propeptins. One prioritized metabolite was identified to be a previously unreported aminopolyol polyketide, funisamine, produced by a cave isolate of Streptosporangium when exposed to mixed culture. The production of funisamine was most significantly increased in mixed culture with Bacillus species. The biosynthetic gene cluster responsible for the production of funisamine was identified via genomic sequencing of the producing strain, Streptosporangium sp. strain KDCAGE35, which facilitated a deduction of its biosynthesis. Together, these data demonstrate that comparative metabolomics can reveal the stimulus-induced production of natural products from diverse microbial phylogenies.IMPORTANCE Microbial secondary metabolites are an important source of biologically active and therapeutically relevant small molecules. However, much of this active molecular diversity is challenging to access due to low production levels or difficulty in discerning secondary metabolites within complex microbial extracts prior to isolation. Here, we demonstrate that ecological stimuli increase secondary metabolite production in phylogenetically diverse actinobacteria isolated from understudied hypogean environments. Additionally, we show that comparative metabolomics linking stimuli to metabolite response data can effectively reveal secondary metabolites within complex biological extracts. This approach highlighted secondary metabolites in almost all observed natural product classes, including low-abundance analogs of biologically relevant metabolites, as well as a new linear aminopolyol polyketide, funisamine. This study demonstrates the generality of activating stimuli to potentiate secondary metabolite production across diverse actinobacterial genera.
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Affiliation(s)
- Brett C Covington
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee, USA
| | - Jeffrey M Spraggins
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee, USA
- Department of Biochemistry, Vanderbilt University, Nashville, Tennessee, USA
- Mass Spectrometry Research Center, Vanderbilt University, Nashville, Tennessee, USA
| | | | - Zachary B Hylton
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee, USA
| | - Brian O Bachmann
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee, USA
- Department of Biochemistry, Vanderbilt University, Nashville, Tennessee, USA
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Genilloud O. Mining Actinomycetes for Novel Antibiotics in the Omics Era: Are We Ready to Exploit This New Paradigm? Antibiotics (Basel) 2018; 7:E85. [PMID: 30257490 PMCID: PMC6316141 DOI: 10.3390/antibiotics7040085] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Revised: 09/20/2018] [Accepted: 09/21/2018] [Indexed: 12/28/2022] Open
Abstract
The current spread of multi-drug resistance in a number of key pathogens and the lack of therapeutic solutions in development to address most of the emerging infections in the clinic that are difficult to treat have become major concerns. Microbial natural products represent one of the most important sources for the discovery of potential new antibiotics and actinomycetes have been one of the most relevant groups that are prolific producers of these bioactive compounds. Advances in genome sequencing and bioinformatic tools have collected a wealth of knowledge on the biosynthesis of these molecules. This has revealed the broad untapped biosynthetic diversity of actinomycetes, with large genomes and the capacity to produce more molecules than previously estimated, opening new opportunities to identify the novel classes of compounds that are awaiting to be discovered. Comparative genomics, metabolomics and proteomics and the development of new analysis and genetic engineering tools provide access to the integration of new knowledge and better understanding of the physiology of actinomycetes and their tight regulation of the production of natural products antibiotics. This new paradigm is fostering the development of new genomic-driven and culture-based strategies, which aims to deliver new chemical classes of antibiotics to be developed to the clinic and replenish the exhausted pipeline of drugs for fighting the progression of infection diseases in the near future.
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Affiliation(s)
- Olga Genilloud
- Fundación MEDINA, Avda Conocimiento 34, 18016 Granada, Spain.
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Complete Genome Sequence of Streptomyces lunaelactis MM109 T, Isolated from Cave Moonmilk Deposits. GENOME ANNOUNCEMENTS 2018; 6:6/21/e00435-18. [PMID: 29798921 PMCID: PMC5968722 DOI: 10.1128/genomea.00435-18] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Streptomyces lunaelactis MM109T is a ferroverdin A (anticholesterol) producer isolated from cave moonmilk deposits. The complete genome sequence of MM109T was obtained by combining Oxford Nanopore MinION and Illumina HiSeq and MiSeq technologies, revealing an 8.4-Mb linear chromosome and two plasmids, pSLUN1 (127,264 bp, linear) and pSLUN2 (46,827 bp, circular).
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High-Throughput Sequencing Analysis of the Actinobacterial Spatial Diversity in Moonmilk Deposits. Antibiotics (Basel) 2018; 7:antibiotics7020027. [PMID: 29561792 PMCID: PMC6023079 DOI: 10.3390/antibiotics7020027] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Revised: 03/15/2018] [Accepted: 03/16/2018] [Indexed: 11/16/2022] Open
Abstract
Moonmilk are cave carbonate deposits that host a rich microbiome, including antibiotic-producing Actinobacteria, making these speleothems appealing for bioprospecting. Here, we investigated the taxonomic profile of the actinobacterial community of three moonmilk deposits of the cave "Grotte des Collemboles" via high-throughput sequencing of 16S rRNA amplicons. Actinobacteria was the most common phylum after Proteobacteria, ranging from 9% to 23% of the total bacterial population. Next to actinobacterial operational taxonomic units (OTUs) attributed to uncultured organisms at the genus level (~44%), we identified 47 actinobacterial genera with Rhodoccocus (4 OTUs, 17%) and Pseudonocardia (9 OTUs, ~16%) as the most abundant in terms of the absolute number of sequences. Streptomycetes presented the highest diversity (19 OTUs, 3%), with most of the OTUs unlinked to the culturable Streptomyces strains that were previously isolated from the same deposits. Furthermore, 43% of the OTUs were shared between the three studied collection points, while 34% were exclusive to one deposit, indicating that distinct speleothems host their own population, despite their nearby localization. This important spatial diversity suggests that prospecting within different moonmilk deposits should result in the isolation of unique and novel Actinobacteria. These speleothems also host a wide range of non-streptomycetes antibiotic-producing genera, and should therefore be subjected to methodologies for isolating rare Actinobacteria.
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