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Dhole A, Shelat H. Non-Rhizobial Endophytes Associated with Nodules of Vigna radiata L. and Their Combined Activity with Rhizobium sp. Curr Microbiol 2022; 79:103. [PMID: 35157135 DOI: 10.1007/s00284-022-02792-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Accepted: 01/31/2022] [Indexed: 11/27/2022]
Abstract
Root nodules of legume plants are devoted for hosting endophytic symbiotic bacteria that fix atmospheric nitrogen but recently proved as a niche for various non-rhizobial endophytes (NRE) also. In the present investigation, one rhizobial and two NRE were isolated and characterized as Rhizobium sp. AAU B3, Bacillus sp. AAU B6 and Bacillus sp. AAU B12. These isolates were studied for in vitro biocontrol activity against two pathogenic fungi. NRE isolates exhibited antifungal activity against root rot causing Macrophomina phaseolina (ITCC-6749) isolated from Vigna radiata and wilt causing pathogen Fusarium udum Butler isolated from Cajanus cajan in liquid as well as on solid medium. Furthermore, their antagonism was increased markedly when combined with Rhizobium sp. Moreover, Bacillus sp. AAU B6 showed amplification of the zwittermicin A gene (~ 950 bp) which is evident for the production of antibiotics. All three isolates showed HCN production in vitro also, Bacillus sp. AAU B12 exhibited amplification of its gene hcnC. Pathogenic fungal hyphae became thin, transparent, and bent as well as fungi lost their normal growth and branching patterns when exposed to volatile compounds produced by NRE. All the 3 isolates produced siderophores, however siderophore production was increased considerably when all three strains are mixed together. Furthermore, all the three isolates produced cell wall degrading enzymes (chitinase, protease, and cellulase) but lipolytic activity was exhibited only by Rhizobium sp. AAU B3. When NRE inoculated in combination of Rhizobium; overcomes the disease severity against M. phaseolina under pot study. Thus, from present study it is concluded that co-inoculation of NRE and Rhizobium sp. can be exploited as biocontrol bio-agents against M. phaseolina in green gram at field levels.
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Affiliation(s)
- Archana Dhole
- B. A. College of Agriculture, Anand Agricultural University, Anand, Gujarat, 388110, India.
| | - Harsha Shelat
- B. A. College of Agriculture, Anand Agricultural University, Anand, Gujarat, 388110, India
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2
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Plant Growth-Promoting Rhizobacteria as Antifungal Antibiotics Producers. Fungal Biol 2022. [DOI: 10.1007/978-3-031-04805-0_5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
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3
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Singh SS, Sharma D, Baindara P, Choksket S, Harshvardhan, Mandal SM, Grover V, Korpole S. Characterization and Antimicrobial Studies of Iturin-Like and Bogorol-Like Lipopeptides From Brevibacillus spp. Strains GI9 and SKDU10. Front Microbiol 2021; 12:729026. [PMID: 34782829 PMCID: PMC8589628 DOI: 10.3389/fmicb.2021.729026] [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: 06/22/2021] [Accepted: 10/05/2021] [Indexed: 11/30/2022] Open
Abstract
Accession numbers for whole-genome sequence of Brevibacillus sp. strain GI9 and SKDU10 are CAGD01000001 to CAGD01000061 and LSSO00000000, respectively. Members of the genus Brevibacillus have been demonstrated to produce a variety of bioactive compounds including polyketides, lipopeptides and bacteriocins. Lipopeptides are non-ribosomally synthesized surface-active compounds with antimicrobial, antitumor, and immune-stimulatory activities. They usually exhibit strong antifungal and antibacterial activities and are considered as promising compounds in controlling fungal diseases. In this study, we have characterized two lipopeptides from Brevibacillus sp. strains GI9 and SKDU10. The corresponding lipopeptides were purified by reverse-phase high-performance liquid chromatography. Mass analysis and characterization by MALDI-TOF-MS (Matrix-assisted laser desorption ionization time-of-flight mass spectrometry) analysis revealed production of an iturin-like lipopeptide by strain GI9 and bogorol-like lipopeptide by strain SKDU10. Both lipopeptides exhibited broad spectrum antibacterial activity and inhibited the growth of various fungi. They showed minimum inhibitory concentration (MIC) values between 90 and 300 μg/ml against indicator strains of bacteria and drug-resistant Candida indicator strains. The lipopeptides did not show phytotoxic effect in seed germination experiments but caused hemolysis. Further, both lipopeptides inhibited the growth of fungi on fruits and vegetables in in vitro experiments, thereby exhibited potential use in biotechnological industry as effective biocontrol agents.
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Affiliation(s)
| | - Deepika Sharma
- CSIR-Institute of Microbial Technology, Chandigarh, India
| | | | | | - Harshvardhan
- CSIR-Institute of Microbial Technology, Chandigarh, India
| | | | - Vishakha Grover
- Dr. Harvansh Singh Judge Institute of Dental Sciences and Hospital, Panjab University, Chandigarh, India
| | - Suresh Korpole
- CSIR-Institute of Microbial Technology, Chandigarh, India
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Genomic insights into biocontrol potential of Bacillus stercoris LJBS06. 3 Biotech 2021; 11:458. [PMID: 34692367 DOI: 10.1007/s13205-021-03000-6] [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] [Accepted: 09/25/2021] [Indexed: 01/20/2023] Open
Abstract
Bacillus spp. have been widely reported with the ability to control plant diseases. In this work, we analyzed the whole genome of LJBS06, which was isolated from grapevine rhizosphere soil. In view of physiological and biochemical characteristics, genome data, and phylogenetic analysis of 16S rRNA, LJBS06 was affiliated with Bacillus stercoris. LJBS06 showed antagonistic activities against a variety of plant pathogens. The inhibition rate of Magnaporthe oryzae was up to 75.05% and the inhibition rates of Colletotrichum gloeosporioides, Coniothyrium diplodiella, and Botrytis cinerea were all above 50% in the plate assays. The genome of LJBS06 had a 4,154,362-bp circular chromosome, with an average GC content of 43.96%, containing an 82,935-bp plasmid with a GC content of 35.18%. The circular chromosome of LJBS06 contained 4231 protein-coding genes, 30 rRNA genes, and 87 tRNA genes, including genes related to the synthesis of plant defense-related enzymes and the promotion of plant growth. Meanwhile, 11 gene clusters involved in biosynthesis of secondary metabolites were present in the genome of LJBS06. In conclusion, our findings indicated that LJBS06 strain had the necessary genetic machinery to control plant pathogens and provided insights for future studies of the biocontrol mechanisms of B. stercoris LJBS06. SUPPLEMENTARY INFORMATION The online version contains supplementary material available at 10.1007/s13205-021-03000-6.
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Autochthonous Acid-Producing Bacteria from Catfish ( Clarias sp.) with Antibacterial Activity against Selected Fish Pathogens: A Preliminary Study. Int J Microbiol 2020; 2020:8526581. [PMID: 32190055 PMCID: PMC7068145 DOI: 10.1155/2020/8526581] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2019] [Revised: 11/08/2019] [Accepted: 01/23/2020] [Indexed: 11/17/2022] Open
Abstract
In this study, the application of an autochthonous microorganism as probiotic on catfish (Clarias sp.) was scarcely reported. This study aimed to obtain probiotic candidates from the digestive tract (intestinal and gastric) of catfish. A total of nine isolates were successfully isolated from the catfish. Almost all bacterial colonies were morphologically round, had flat edges, were yellow, and produced clear zones as a sign of producing acid during culture. The analysis showed that the three isolates had the best activity in inhibiting fish pathogen isolates. Furthermore, molecular analysis revealed that those three isolates were Bacillus velezensis UB-C1, Bacillus amyloliquifaciens UB-C5, and Bacillus cereus UB-C8. Interestingly, those three bacteria were non-lactic acid bacteria.
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6
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Garcia-Gutierrez E, Mayer MJ, Cotter PD, Narbad A. Gut microbiota as a source of novel antimicrobials. Gut Microbes 2018; 10:1-21. [PMID: 29584555 PMCID: PMC6363078 DOI: 10.1080/19490976.2018.1455790] [Citation(s) in RCA: 140] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 03/13/2018] [Accepted: 03/19/2018] [Indexed: 02/08/2023] Open
Abstract
Bacteria, Archaea, Eukarya and viruses coexist in the human gut, and this coexistence is functionally balanced by symbiotic or antagonistic relationships. Antagonism is often characterized by the production of antimicrobials against other organisms occupying the same environmental niche. Indeed, close co-evolution in the gut has led to the development of specialized antimicrobials, which is attracting increased attention as these may serve as novel alternatives to antibiotics and thereby help to address the global problem of antimicrobial resistance. The gastrointestinal (GI) tract is especially suitable for finding novel antimicrobials due to the vast array of microbes that inhabit it, and a considerable number of antimicrobial producers of both wide and narrow spectrum have been described. In this review, we summarize some of the antimicrobial compounds that are produced by bacteria isolated from the gut environment, with a special focus on bacteriocins. We also evaluate the potential therapeutic application of these compounds to maintain homeostasis in the gut and the biocontrol of pathogenic bacteria.
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Affiliation(s)
- Enriqueta Garcia-Gutierrez
- Gut Health and Food Safety Institute Strategic Programme, Quadram Institute Bioscience, Norwich, UK
- Food Bioscience Department, Teagasc Food Research Centre, Fermoy, Ireland
| | - Melinda J. Mayer
- Gut Health and Food Safety Institute Strategic Programme, Quadram Institute Bioscience, Norwich, UK
| | - Paul D. Cotter
- Food Bioscience Department, Teagasc Food Research Centre, Fermoy, Ireland
- APC Microbiome, Ireland
| | - Arjan Narbad
- Gut Health and Food Safety Institute Strategic Programme, Quadram Institute Bioscience, Norwich, UK
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Padaria JC, Tarafdar A, Raipuria R, Lone SA, Gahlot P, Shakil NA, Kumar J. Identification of phenazine-1-carboxylic acid gene (phc CD) from Bacillus pumilus MTCC7615 and its role in antagonism against Rhizoctonia solani. J Basic Microbiol 2016; 56:999-1008. [PMID: 27106067 DOI: 10.1002/jobm.201500574] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2015] [Accepted: 03/28/2016] [Indexed: 11/10/2022]
Abstract
Bacillus pumilus MTCC7615, a biocontrol agent isolated from rice rhizosphere was characterized to be antagonistic to Rhizoctonia solani, the pathogen causing sheath blight disease of rice. The phenazine-1-carboxylic acid gene (phc CD) of this bacterium was PCR amplified (1400 bp), cloned, and sequenced. The sequence analysis revealed the presence of two ORFs of phc CD gene commonly found in Pseudomonas species. The sequence showed 98% similarity to phc CD gene of the Pseudomonas isolate LBUM223 (DQ788993). The crude antibiotic extract from B. pumilus MTCC7615 was observed to inhibit mycelial growth of R. solani under in vitro conditions. The HPLC analysis of crude antibiotic extract from B. pumilus MTCC7615 confirmed the presence of phenazine. The study has also reported the presence of phc CD gene which is responsible for the synthesis of phenazine-1-carboxylic acid in B. pumilus. The ability of the bacterial isolate to control sheath blight disease in rice seedlings under in vivo conditions was confirmed by the pot culture experiment. The structural and functional genomics of phc C and phc D genes would lead to a better understanding of phenazine biosynthesis in B. pumilus for its efficient utilization in plant protection strategies.
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Affiliation(s)
- Jasdeep Chatrath Padaria
- Biotechnology and Climate Change Group, National Research Centre on Plant Biotechnology, Pusa Campus, New Delhi, India.
| | - Avijit Tarafdar
- Biotechnology and Climate Change Group, National Research Centre on Plant Biotechnology, Pusa Campus, New Delhi, India
| | - Rajkumar Raipuria
- Biotechnology and Climate Change Group, National Research Centre on Plant Biotechnology, Pusa Campus, New Delhi, India
| | - Showkat Ahmad Lone
- Biotechnology and Climate Change Group, National Research Centre on Plant Biotechnology, Pusa Campus, New Delhi, India
| | - Pallavi Gahlot
- Biotechnology and Climate Change Group, National Research Centre on Plant Biotechnology, Pusa Campus, New Delhi, India
| | - Najam A Shakil
- Division of Agricultural Chemicals, Indian Agricultural Research Institute, Pusa Campus, New Delhi, India
| | - Jitendra Kumar
- Division of Agricultural Chemicals, Indian Agricultural Research Institute, Pusa Campus, New Delhi, India
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8
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Luo Y, Ruan LF, Zhao CM, Wang CX, Peng DH, Sun M. Validation of the intact zwittermicin A biosynthetic gene cluster and discovery of a complementary resistance mechanism in Bacillus thuringiensis. Antimicrob Agents Chemother 2011; 55:4161-9. [PMID: 21730118 PMCID: PMC3165285 DOI: 10.1128/aac.00111-11] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2011] [Revised: 02/26/2011] [Accepted: 06/23/2011] [Indexed: 11/20/2022] Open
Abstract
Zwittermicin A (ZmA) is a hybrid polyketide-nonribosomal peptide produced by certain Bacillus cereus group strains. It displays broad-spectrum antimicrobial activity. Its biosynthetic pathway in B. cereus has been proposed through analysis of the nonribosomal peptide synthetase (NRPS) and polyketide synthase (PKS) modules involved in ZmA biosynthesis. In this study, we constructed a bacterial artificial chromosome (BAC) library from Bacillus thuringiensis subsp. kurstaki strain YBT-1520 genomic DNA. The presence of known genes involved in the biosynthesis of ZmA in this BAC library was investigated by PCR techniques. Nine positive clones were identified, two of which (covering an approximately 60-kb region) could confer ZmA biosynthesis ability upon B. thuringiensis BMB171 after simultaneous transfer into this host by two compatible shuttle BAC vectors. Another previously unidentified gene cluster, named zmaWXY, was found to improve the yield of ZmA and was experimentally defined to function as a ZmA resistance transporter which expels ZmA from the cells. Putative transposase genes were detected on the flanking regions of the two gene clusters (the ZmA synthetic cluster and zmaWXY), which suggests a mobile nature of these two gene clusters. The intact ZmA gene cluster was validated, and a resistance mechanism complementary to that for zmaR (the previously identified ZmA self-resistance gene) was revealed. This study also provided a straightforward strategy to isolate and identify a huge gene cluster from Bacillus.
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Affiliation(s)
- Yi Luo
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, People's Republic of China
| | - Li-Fang Ruan
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, People's Republic of China
| | - Chang-Ming Zhao
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, People's Republic of China
| | - Cheng-Xian Wang
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, People's Republic of China
| | - Dong-Hai Peng
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, People's Republic of China
| | - Ming Sun
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, People's Republic of China
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9
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10
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Rogers EW, Dalisay DS, Molinski TF. Zwittermicin A: synthesis of analogs and structure-activity studies. Bioorg Med Chem Lett 2010; 20:2183-5. [PMID: 20189808 DOI: 10.1016/j.bmcl.2010.02.032] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2010] [Revised: 02/04/2010] [Accepted: 02/08/2010] [Indexed: 11/18/2022]
Abstract
Analogs and diastereomers of the natural product zwittermicin A were prepared. SAR studies of these compounds reveal the antifungal activity to be dependent singularly upon the natural constitution and configuration.
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Affiliation(s)
- Evan W Rogers
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, United States
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11
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Athukorala SNP, Fernando WGD, Rashid KY. Identification of antifungal antibiotics of Bacillus species isolated from different microhabitats using polymerase chain reaction and MALDI-TOF mass spectrometry. Can J Microbiol 2010; 55:1021-32. [PMID: 19898544 DOI: 10.1139/w09-067] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Although many Bacillus species are known to be good antibiotic producers capable of acting as biocontrol agents, the underlying antimicrobial mechanisms are often poorly understood. In this study, 21 Bacillus strains, demonstrating over 50% mycelial inhibition against Sclerotinia sclerotiorum as well as significant control in plant assays, were examined for the presence of antibiotic biosynthetic genes. Primers specific for bacillomycin D, iturin A, surfactin, mycosubtilin, fengycin, and zwittermicin A were used to amplify biosynthetic genes from these bacteria using PCR. The majority of strains harbored surfactin (21/21) and iturin A (20/21) biosynthetic genes. Three strains (Bacillus subtilis 3057, Bacillus amyloliquefaciens BS6, and Bacillus mycoides 4079) were positive for bacillomycin D, whereas 4 strains (B. subtilis H-08-02, B. subtilis 3057, B. amyloliquefaciens BS6, and B. mycoides 4079) showed the presence of the fengycin biosynthetic gene. The zwittermicin A gene was detected in B. mycoides S, Bacillus thuringiensis BS8, and B. amyloliquefaciens BS6. Sequence analysis of purified PCR products revealed homology with corresponding genes from other Bacillus sp. in the GenBank database. Production of particular antibiotics in strains BS6, H-08-02, 3057, and 4079 was confirmed through matrix-assisted laser desorption ionization - time of flight - mass spectroscopy (MALDI-TOF-MS). This study revealed the equivalent capability of different Bacillus strains from various microhabitats to produce the above-mentioned antibiotics and highlights the possibility of using some strains as potential biocontrol agents under different microhabitats distant from their original habitat. Furthermore, it will enable researchers to develop rational strategies for the application of the antagonists and their metabolites within an agroecosystem. To the best of our knowledge, this is the first report of a B. mycoides strain that carries biosynthetic genes and produces fengycin and surfactin.
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Rogers EW, Molinski TF. (+)-Zwittermicin A. Rapid assembly of C9-C15 and a formal total synthesis. J Org Chem 2009; 74:7660-4. [PMID: 19746943 DOI: 10.1021/jo901007v] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A short, enantioselective synthesis of the C9-C15 portion of (+)-zwittermicin A is reported that exploits directional functionalization of the known hepta-2,5-diyne-1,7-diol by partial reduction of the two triple bonds followed by Sharpless asymmetric epoxidation and boron-directed double ring-opening with sodium azide under Miyashita conditions. Subsequent desymmetrization of the C(2)-symmetric diazidotetraol product converges upon (-)-3--the enantiomer of the key intermediate of our earlier structural proof and synthesis of (-)-zwittermicin A--and constitutes a formal synthesis of (+)-zwitttermicin A.
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Affiliation(s)
- Evan W Rogers
- Department of Chemistry and Biochemistry and Skaggs School of Pharmacy, University of California, San Diego, 9500 Gilman Dr., La Jolla, California 92093, USA
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Rasooli I, Shayegh S, Astaneh S. The effect ofMentha spicataandEucalyptus camaldulensisessential oils on dental biofilm. Int J Dent Hyg 2009; 7:196-203. [PMID: 19659716 DOI: 10.1111/j.1601-5037.2009.00389.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- I Rasooli
- Department of Biology, Shahed University, Tehran, Iran.
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14
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Screening siderophore producing bacteria as potential biological control agent for fungal rice pathogens in Thailand. World J Microbiol Biotechnol 2009. [DOI: 10.1007/s11274-009-0090-7] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Somers E, Vanderleyden J, Srinivasan M. Rhizosphere Bacterial Signalling: A Love Parade Beneath Our Feet. Crit Rev Microbiol 2008; 30:205-40. [PMID: 15646398 DOI: 10.1080/10408410490468786] [Citation(s) in RCA: 165] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Plant roots support the growth and activities of a wide variety of microorganisms that may have a profound effect on the growth and/or health of plants. Among these microorganisms, a high diversity of bacteria have been identified and categorized as deleterious, beneficial, or neutral with respect to the plant. The beneficial bacteria, termed plant growth-promoting rhizobacteria (PGPR), are widely studied by microbiologists and agronomists because of their potential in plant production. Azospirillum, a genus of versatile PGPR, is able to enhance the plant growth and yield of a wide range of economically important crops in different soils and climatic regions. Plant beneficial effects of Azospirillum have mainly been attributed to the production of phytohormones, nitrate reduction, and nitrogen fixation, which have been subject of extensive research throughout the years. These elaborate studies made Azospirillum one of the best-characterized genera of PGPR. However, the genetic and molecular determinants involved in the initial interaction between Azospirillum and plant roots are not yet fully understood. This review will mainly highlight the current knowledge on Azospirillum plant root interactions, in the context of preceding and ongoing research on the association between plants and plant growth-promoting rhizobacteria.
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Affiliation(s)
- E Somers
- Centre of Microbial and Plant Genetics, K U Leuven, Heverlee, Belgium.
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Zhou Y, Choi YL, Sun M, Yu Z. Novel roles of Bacillus thuringiensis to control plant diseases. Appl Microbiol Biotechnol 2008; 80:563-72. [DOI: 10.1007/s00253-008-1610-3] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2008] [Revised: 07/08/2008] [Accepted: 07/08/2008] [Indexed: 10/21/2022]
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17
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Shao T, Bai L, Zhang J, Wang G, Liu D, Li Z, Liu J, Song F, Huang D. A nonribosomal peptide synthetase gene tzw1 is involved in zwittermicin A biosynthesis in Bacillus thuringiensis G03. Curr Microbiol 2008; 57:61-5. [PMID: 18446411 DOI: 10.1007/s00284-008-9153-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2008] [Accepted: 02/08/2008] [Indexed: 11/30/2022]
Abstract
A 4.20-kb SspI fragment from Bacillus thuringiensis G03 was cloned and sequenced. Sequencing analysis revealed two complete open reading frames (ORF; tzw1 and tzw2), and one incomplete ORF (tzw3) (GenBank accession no. EU293887). Tzw1 encodes a putative nonribosomal peptide synthetase with thiolation and condensation domains localized at the C-termini, whereas tzw2 and tzw3 encode acyl carrier protein and Acyl-CoA dehydrogenase, respectively. To investigate the function of tzw1 in zwittermicin A (ZA) biosynthesis, an in-frame deletion of 1,461 bp within tzw1 was constructed. The mutant abolished ZA production. Complementation of the mutant with cloned tzw1 restored ZA productivity. These results revealed that tzw1 is required for ZA biosynthesis in B. thuringiensis G03.
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Affiliation(s)
- Tiemei Shao
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, PR China
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18
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Pluvinage B, Dairou J, Possot OM, Martins M, Fouet A, Dupret JM, Rodrigues-Lima F. Cloning and molecular characterization of three arylamine N-acetyltransferase genes from Bacillus anthracis: identification of unusual enzymatic properties and their contribution to sulfamethoxazole resistance. Biochemistry 2007; 46:7069-78. [PMID: 17511472 DOI: 10.1021/bi700351w] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The arylamine N-acetyltransferases (NATs) are xenobiotic-metabolizing enzymes that catalyze the N-acetylation of arylamines and their N-hydroxylated metabolites. These enzymes play a key role in detoxication of numerous drugs and xenobiotics. We report here the cloning, functional expression, and characterization of three new NAT genes (termed banatA, banatB, and banatC) from the pathogen Bacillus anthracis. The sequences of the corresponding proteins are approximately 30% identical with those of characterized eukaryotic and prokaryotic NAT enzymes, and the proteins were recognized by an anti-NAT antibody. The three genes were endogenously expressed in B. anthracis, and NAT activity was found in cell extracts. The three NAT homologues exhibited distinct structural and enzymatic properties, some of which have not previously been observed with other NAT enzymes. Recombinant BanatC displayed strong NAT activity toward several prototypic NAT substrates, including the sulfonamide antibiotic sulfamethoxazole (SMX). As opposed to BanatC, BanatB also had acetyl-CoA (AcCoA) and p-nitrophenyl acetate (PNPA) hydrolysis activity in the absence of arylamine substrates, indicating that it may act as an AcCoA hydrolase. BanatA was devoid of NAT or AcCoA/PNPA hydrolysis activities, suggesting that it may be a new bacterial NAT-like protein with unknown function. Expression of BanatC in Escherichia coli afforded higher-than-normal resistance to SMX in the recombinant bacteria, whereas an inactive mutant of the enzyme did not. These data indicate that BanatC could contribute to the resistance of B. anthracis to SMX.
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Affiliation(s)
- Benjamin Pluvinage
- Laboratoire de Cytophysiologie et Toxicologie Cellulaire, EA 1553, Université Paris 7-Denis Diderot, 75005 Paris, France
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Zhao C, Luo Y, Song C, Liu Z, Chen S, Yu Z, Sun M. Identification of three Zwittermicin A biosynthesis-related genes from Bacillus thuringiensis subsp. kurstaki strain YBT-1520. Arch Microbiol 2007; 187:313-9. [PMID: 17225146 DOI: 10.1007/s00203-006-0196-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2006] [Revised: 11/06/2006] [Accepted: 11/14/2006] [Indexed: 11/26/2022]
Abstract
Zwittermicin A (ZwA) is a novel, broad-spectrum linear aminopolyol antibiotic produced by some Bacillus cereus and Bacillus thuringiensis. However, only part of its biosynthesis cluster has been identified and characterized from B. cereus UW85. To better understand the biosynthesis cluster of ZwA, a bacterial artificial chromosome (BAC) library of B. thuringiensis subsp. kurstaki strain YBT-1520, a ZwA-producing strain, was constructed. Two BAC clones, 1F8 and 5E2, were obtained by PCR, which overlap the known ZwA biosynthesis cluster of B. cereus UW85. This ZwA biosynthesis cluster is at least 38.6 kb and is located on the chromosome, instead of the plasmid. Partial DNA sequencing revealed both BAC clones carry three new ZwA biosynthesis-related genes, zwa6, zwa5A and zwa5B, which were found at the corresponding location of B. cereus UW85. Putative amino acid sequences of these genes shown that ZWA6 is homologous to a typical carbamoyltransferase from Streptomyces avermitilis, while ZWA5A and ZWA5B are homologs of cysteine synthetase and ornithine cyclodeaminase which jointly synthesize 2,3-diaminopropionate in the viomycin biosynthesis pathway, respectively. The identification of these three genes further supports the hypothesized ZwA biosynthesis pathway.
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Affiliation(s)
- Changming Zhao
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
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Zhang Y, Fernando WGD, de Kievit TR, Berry C, Daayf F, Paulitz TC. Detection of antibiotic-related genes from bacterial biocontrol agents with polymerase chain reaction. Can J Microbiol 2006; 52:476-81. [PMID: 16699573 DOI: 10.1139/w05-152] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Pseudomonas chlororaphis PA23, Pseudomonas spp. strain DF41, and Bacillus amyloliquefaciens BS6 consistently inhibit infection of canola petals by Sclerotinia sclerotiorum in both greenhouse and field experiments. Bacillus thuringiensis BS8, Bacillus cereus L, and Bacillus mycoides S have shown significant inhibition against S. sclerotiorum on plate assays. The presence of antibiotic biosynthetic or self-resistance genes in these strains was investigated with polymerase chain reaction and, in one case, Southern blotting. Thirty primers were used to amplify (i) antibiotic biosythetic genes encoding phenazine-1-carboxylic acid, 2,4-diacetylphloroglucinol, pyoluteorin, and pyrrolnitrin, and (ii) the zwittermicin A self-resistance gene. Our findings revealed that the fungal antagonist P. chlororaphis PA23 contains biosynthetic genes for phenazine-1-carboxylic acid and pyrrolnitrin. Moreover, production of these compounds was confirmed by high performance liquid chromatography. Pseudomonas spp. DF41 and B. amyloliquefaciens BS6 do not appear to harbour genes for any of the antibiotics tested. Bacillus thuringiensis BS8, B. cereus L, and B. mycoides S contain the zwittermicin A self-resistance gene. This is the first report of zmaR in B. mycoides.
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Affiliation(s)
- Y Zhang
- Department of Plant Science, University of Manitoba, Winnipeg, Canada
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21
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Saile E, Koehler TM. Bacillus anthracis multiplication, persistence, and genetic exchange in the rhizosphere of grass plants. Appl Environ Microbiol 2006; 72:3168-74. [PMID: 16672454 PMCID: PMC1472387 DOI: 10.1128/aem.72.5.3168-3174.2006] [Citation(s) in RCA: 103] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Bacillus anthracis, the causative agent of anthrax, is known for its rapid proliferation and dissemination in mammalian hosts. In contrast, little information exists regarding the lifestyle of this important pathogen outside of the host. Considering that Bacillus species, including close relatives of B. anthracis, are saprophytic soil organisms, we investigated the capacity of B. anthracis spores to germinate in the rhizosphere and to establish populations of vegetative cells that could support horizontal gene transfer in the soil. Using a simple grass plant-soil model system, we show that B. anthracis strains germinate on and around roots, growing in characteristic long filaments. From 2 to 4 days postinoculation, approximately one-half of the B. anthracis CFU recovered from soil containing grass seedlings arose from heat-sensitive organisms, while B. anthracis CFU retrieved from soil without plants consisted of primarily heat-resistant spores. Co-inoculation of the plant-soil system with spores of a fertile B. anthracis strain carrying the tetracycline resistance plasmid pBC16 and a selectable B. anthracis recipient strain resulted in transfer of pBC16 from the donor to the recipient as early as 3 days postinoculation. Our findings demonstrate that B. anthracis can survive as a saprophyte outside of the host. The data suggest that horizontal gene transfer in the rhizosphere of grass plants may play a role in the evolution of the Bacillus cereus group species.
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Affiliation(s)
- Elke Saile
- Department of Microbiology and Molecular Genetics, University of Texas-Houston Medical School, 6431 Fannin St., JFB 1.765, Houston, TX 77030, USA
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Danshiitsoodol N, de Pinho CA, Matoba Y, Kumagai T, Sugiyama M. The mitomycin C (MMC)-binding protein from MMC-producing microorganisms protects from the lethal effect of bleomycin: crystallographic analysis to elucidate the binding mode of the antibiotic to the protein. J Mol Biol 2006; 360:398-408. [PMID: 16756991 DOI: 10.1016/j.jmb.2006.05.017] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2006] [Revised: 05/01/2006] [Accepted: 05/05/2006] [Indexed: 10/24/2022]
Abstract
Antibiotic-producing microorganisms must be protected from the lethal effect of their own antibiotic. We have previously determined the X-ray crystal structure of the bleomycin (Bm)-binding protein, designated BLMA, as a self-resistance determinant from Bm-producing Streptomyces verticillus, which suggests that the binding of the first Bm to one of two pockets formed in the BLMA homodimer induces the cooperative binding of the second Bm to the other pocket. In the present study, we noticed that the X-ray crystallographic structure of a self-resistance determinant from a mitomycin C-producing microorganism, designated MRDP, reveals similarity to the folding pattern on the BLMA, although no sequence homology exists. To clarify the hypothesis that MRDP may function as a resistance determinant to Bm, we characterized and determined the crystal structure of MRDP complexed with the Cu(II)-bound form of BmA(2) grouped into the Bm family of antibiotics. The biochemical and structural studies for Bm binding provide evidence that the first Bm binds anti-cooperatively to a pocket of MRDP with binding affinity of the nanomolar order, whereas the second Bm binds to the other pocket, which has binding affinity of the micromolar order. The invisibility of the second Bm in the structure agrees with the observation that Escherichia coli-expressing MRDP displays lower resistance to Bm than that expressing BLMA. The structure of MRDP, which is complexed with the Cu(II)-bound BmA(2), revealed that the gamma-aminopropyldimethylsulphonium moiety of the antibiotic is sandwiched between the peripheral residues of the binding pocket and that its positively charged sulphonium head is accommodated completely in the negatively charged region of the MRDP pocket. Furthermore, the Cu(II)-bound BmA(2) has a very compact structure, in which the bithiazole ring of BmA(2) is folded back to the metal-binding domain.
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Affiliation(s)
- Narandalai Danshiitsoodol
- Department of Molecular Microbiology and Biotechnology, Graduate School of Biomedical Sciences, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima 734-8551, Japan
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Filoche SK, Soma K, Sissons CH. Antimicrobial effects of essential oils in combination with chlorhexidine digluconate. ACTA ACUST UNITED AC 2005; 20:221-5. [PMID: 15943766 DOI: 10.1111/j.1399-302x.2005.00216.x] [Citation(s) in RCA: 102] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The aim of the present study was to compare antimicrobial effects of essential oils alone and in combination with chlorhexidine digluconate against planktonic and biofilm cultures of Streptococcus mutans and Lactobacillus plantarum. The essential oils included cinnamon, tea-tree (Melaleuca alternifola), manuka (Leptospermum scoparium), Leptospermum morrisonii, arnica, eucalyptus, grapefruit, the essential oil mouthrinse Cool Mint Listerine and two of its components, menthol and thymol. Cinnamon exhibited the greatest antimicrobial potency (1.25-2.5 mg/ml). Manuka, L. morrisonii, tea-tree oils, and thymol also showed antimicrobial potency but to a lesser extent. The combination effect of the essential oil-chlorhexidine was greater against biofilm cultures of both S. mutans and L. plantarum than against planktonic cultures. The amount of chlorhexidine required to achieve an equivalent growth inhibition against the biofilm cultures was reduced 4-10-fold in combination with cinnamon, manuka, L. morrisonii, thymol, and Listerine. We conclude that there may be a role for essential oils in the development of novel anticaries treatments.
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Affiliation(s)
- S K Filoche
- Dental Research Group, Department of Pathology and Molecular Medicine, Wellington School of Medicine and Health Sciences, University of Otago, New Zealand
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Nair JR, Narasimman G, Sekar V. Cloning and partial characterization of zwittermicin A resistance gene cluster from Bacillus thuringiensis subsp. kurstaki strain HD1. J Appl Microbiol 2004; 97:495-503. [PMID: 15281929 DOI: 10.1111/j.1365-2672.2004.02312.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
AIM The study seeks to shed light on the aminopolyol, broad-spectrum antibiotic zwittermicin A gene cluster of Bacillus thuringiensis subsp. kurstaki HD1 and to identify any new uncharacterized genes with an eventual goal to establish a better understanding of the resistance gene cluster. METHODS AND RESULTS We screened 51 serovars of B. thuringiensis by PCR and identified 12 zmaR-positive strains. The zmaR-positive B. thuringiensis subsp. kurstaki HD1 strain displayed inhibition zones against indicator fungal strain Phytophthora meadii and bacterial strain Erwinia herbicola as well as against Rhizopus sp., Xanthomonas campestris and B. thuringiensis subsp. finitimus. The zmaR gene cluster of strain HD1 was partially cloned using a lambda library and was extensively characterized based on the information available from a study performed on a similar group of genes in Bacillus cereus. CONCLUSIONS Three of the five genes in the zwittermicin gene cluster, including the zmaR gene, had counterparts in B. cereus, and the other two were new members of the B. thuringiensis zmaR gene cluster. SIGNIFICANCE AND IMPACT OF THE STUDY The two new genes were extensively analysed and the data is presented. Understanding antifungal activity of B. thuringiensis may help us to design suitable Cry toxin delivery agents with antifungal activity as well as enhanced insecticidal activity.
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Affiliation(s)
- J R Nair
- Department of Molecular Microbiology, School of Biotechnology, Madurai Kamaraj University, Madurai, India
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Emmert EAB, Klimowicz AK, Thomas MG, Handelsman J. Genetics of zwittermicin a production by Bacillus cereus. Appl Environ Microbiol 2004; 70:104-13. [PMID: 14711631 PMCID: PMC321298 DOI: 10.1128/aem.70.1.104-113.2004] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Zwittermicin A represents a new chemical class of antibiotic and has diverse biological activities, including suppression of oomycete diseases of plants and potentiation of the insecticidal activity of Bacillus thuringiensis. To identify genes involved in zwittermicin A production, we generated 4,800 transposon mutants of B. cereus UW101C and screened them for zwittermicin A accumulation. Nine mutants did not produce detectable zwittermicin A, and one mutant produced eightfold more than the parent strain. The DNA flanking the transposon insertions in six of the nine nonproducing mutants contains significant sequence similarity to genes involved in peptide and polyketide antibiotic biosynthesis. The mutant that overproduced zwittermicin A contained a transposon insertion immediately upstream from a gene that encodes a deduced protein that is a member of the MarR family of transcriptional regulators. Three genes identified by the mutant analysis mapped to a region that was previously shown to carry the zwittermicin A self-resistance gene, zmaR, and a biosynthetic gene (E. A. Stohl, J. L. Milner, and J. Handelsman, Gene 237:403-411, 1999). Further sequencing of this region revealed genes proposed to encode zwittermicin A precursor biosynthetic enzymes, in particular, those involved in the formation of the aminomalonyl- and hydroxymalonyl-acyl carrier protein intermediates. Additionally, nonribosomal peptide synthetase (NRPS) and polyketide synthase (PKS) homologs are present, suggesting that zwittermicin A is synthesized by a mixed NRPS/PKS pathway.
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Affiliation(s)
- Elizabeth A B Emmert
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
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Duffy B, Schouten A, Raaijmakers JM. Pathogen self-defense: mechanisms to counteract microbial antagonism,. ANNUAL REVIEW OF PHYTOPATHOLOGY 2003; 41:501-538. [PMID: 12730392 DOI: 10.1146/annurev.phyto.41.052002.095606] [Citation(s) in RCA: 90] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Natural and agricultural ecosystems harbor a wide variety of microorganisms that play an integral role in plant health, crop productivity, and preservation of multiple ecosystem functions. Interactions within and among microbial communities are numerous and range from synergistic and mutualistic to antagonistic and parasitic. Antagonistic and parasitic interactions have been exploited in the area of biological control of plant pathogenic microorganisms. To date, biocontrol is typically viewed from the perspective of how antagonists affect pathogens. This review examines the other face of this interaction: how plant pathogens respond to antagonists and how this can affect the efficacy of biocontrol. Just as microbial antagonists utilize a diverse arsenal of mechanisms to dominate interactions with pathogens, pathogens have surprisingly diverse responses to counteract antagonism. These responses include detoxification, repression of biosynthetic genes involved in biocontrol, active efflux of antibiotics, and antibiotic resistance. Understanding pathogen self-defense mechanisms for coping with antagonist assault provides a novel approach to improving the durability of biologically based disease control strategies and has implications for the deployment of transgenes (microorganisms or plants).
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Affiliation(s)
- Brion Duffy
- Swiss Federal Research Center for Fruit Production, Viticulture and Horticulture, FAW, Postfach 185, CH-8820 Wadenswil, Switzerland.
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Abstract
The goal of this study was to identify the biosynthetic cluster for zwittermicin A, a novel, broad spectrum, aminopolyol antibiotic produced by Bacillus cereus. The nucleotide sequence of 2.7kb of DNA flanking the zwittermicin A self-resistance gene, zmaR, from B. cereus UW85 revealed three open reading frames (ORFs). Of these ORFs, two had sequence similarity to acyl-CoA dehydrogenases and polyketide synthases, respectively. Insertional inactivation demonstrated that orf2 is necessary for zwittermicin A production and that zmaR is necessary for high-level resistance to zwittermicin A but is not required for zwittermicin A production. Expression of ZmaR was temporally associated with zwittermicin A production. The results suggest that zmaR is part of a cluster of genes that is involved in zwittermicin A biosynthesis, representing the first biosynthetic pathway for an aminopolyol antibiotic.
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Affiliation(s)
- E A Stohl
- Department of Plant Pathology, University of Wisconsin-Madison, 1630 Linden Drive, Madison, WI 53706, USA
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28
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Stohl EA, Brady SF, Clardy J, Handelsman J. ZmaR, a novel and widespread antibiotic resistance determinant that acetylates zwittermicin A. J Bacteriol 1999; 181:5455-60. [PMID: 10464220 PMCID: PMC94055 DOI: 10.1128/jb.181.17.5455-5460.1999] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
ZmaR is a resistance determinant of unusual abundance in the environment and confers on gram-positive and gram-negative bacteria resistance to zwittermicin A, a novel broad-spectrum antibiotic produced by species of Bacillus. The ZmaR protein has no sequence similarity to proteins of known function; thus, the purpose of the present study was to determine the function of ZmaR in vitro. Cell extracts of E. coli containing zmaR inactivated zwittermicin A by covalent modification. Chemical analysis of inactivated zwittermicin A by 1H NMR, 13C NMR, and high- and low-resolution mass spectrometry demonstrated that the inactivated zwittermicin A was acetylated. Purified ZmaR protein inactivated zwittermicin A, and biochemical assays for acetyltransferase activity with [14C]acetyl coenzyme A demonstrated that ZmaR catalyzes the acetylation of zwittermicin A with acetyl coenzyme A as a donor group, suggesting that ZmaR may constitute a new class of acetyltransferases. Our results allow us to assign a biochemical function to a resistance protein that has no sequence similarity to proteins of known function, contributing fundamental knowledge to the fields of antibiotic resistance and protein function.
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Affiliation(s)
- E A Stohl
- Department of Plant Pathology, University of Wisconsin, Madison, Wisconsin 53706, USA
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Rondon MR, Raffel SJ, Goodman RM, Handelsman J. Toward functional genomics in bacteria: analysis of gene expression in Escherichia coli from a bacterial artificial chromosome library of Bacillus cereus. Proc Natl Acad Sci U S A 1999; 96:6451-5. [PMID: 10339608 PMCID: PMC26902 DOI: 10.1073/pnas.96.11.6451] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/1998] [Accepted: 03/30/1999] [Indexed: 11/18/2022] Open
Abstract
As the study of microbes moves into the era of functional genomics, there is an increasing need for molecular tools for analysis of a wide diversity of microorganisms. Currently, biological study of many prokaryotes of agricultural, medical, and fundamental scientific interest is limited by the lack of adequate genetic tools. We report the application of the bacterial artificial chromosome (BAC) vector to prokaryotic biology as a powerful approach to address this need. We constructed a BAC library in Escherichia coli from genomic DNA of the Gram-positive bacterium Bacillus cereus. This library provides 5.75-fold coverage of the B. cereus genome, with an average insert size of 98 kb. To determine the extent of heterologous expression of B. cereus genes in the library, we screened it for expression of several B. cereus activities in the E. coli host. Clones expressing 6 of 10 activities tested were identified in the library, namely, ampicillin resistance, zwittermicin A resistance, esculin hydrolysis, hemolysis, orange pigment production, and lecithinase activity. We analyzed selected BAC clones genetically to identify rapidly specific B. cereus loci. These results suggest that BAC libraries will provide a powerful approach for studying gene expression from diverse prokaryotes.
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Affiliation(s)
- M R Rondon
- Department of Plant Pathology, University of Wisconsin-Madison, 1630 Linden Drive, Russell Laboratories, Madison, WI 53706, USA
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Stabb EV, Handelsman J. Genetic analysis of zwittermicin A resistance in Escherichia coli: effects on membrane potential and RNA polymerase. Mol Microbiol 1998; 27:311-22. [PMID: 9484887 DOI: 10.1046/j.1365-2958.1998.00678.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Zwittermicin A is a novel aminopolyol antibiotic that represents a new structural class of antibiotic and has diverse biological activities, including the suppression of plant disease and the ability to inhibit prokaryotic and eukaryotic cells. To enhance our fundamental understanding and applications of zwittermicin A, we elucidated mechanisms of zwittermicin A resistance in Escherichia coli. Two classes of zwittermicin A-resistant mutants of E. coli were selected and characterized. One class included mutants altered in hemA, hemB, hemL, ubi, cydAB or atp, which were defective in generating a proton motive force (PMF) and resistant to aminoglycosides. The mutant analysis, coupled with physiological data, indicated an association between the electrical membrane potential (deltapsi) component of PMF and zwittermicin A sensitivity. A second class of zwittermicin A-resistant mutants was aminoglycoside sensitive and was affected in rpoB and rpoC, genes that encode subunits of RNA polymerase. The rpoB and rpoC mutants suggested that zwittermicin A might inhibit transcription, DNA replication, DNA gyrase or topoisomerase I; however, we found no further evidence to support any of these as the target for zwittermicin A. This study elucidated the genetic mechanisms of zwittermicin A resistance in E. coli. The results suggest that deltapsi drives zwittermicin A uptake, and that, unlike other antibiotics for which resistance maps in rpoB or rpoC, zwittermicin A does not cause the rapid cessation of DNA or RNA synthesis, suggesting a unique mechanism of antibiosis.
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Affiliation(s)
- E V Stabb
- Department of Bacteriology, University of Wisconsin, Madison 53706, USA
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Handelsman J, Stabb EV. Biocontrol of Soilborne Plant Pathogens. THE PLANT CELL 1996; 8:1855-1869. [PMID: 12239367 PMCID: PMC161320 DOI: 10.1105/tpc.8.10.1855] [Citation(s) in RCA: 129] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Affiliation(s)
- J. Handelsman
- Department of Plant Pathology, University of Wisconsin, 1630 Linden Drive, Russell Laboratories, Madison, Wisconsin 53706
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