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Abstract
Core biochemical pathways such as Fatty-acid synthesis II (FAS II) is ascribed to the synthesis of fatty-acids, biotin and lipoic acid in prokaryotes. It has two dehydrogenases namely, FabG and FabI which interact with the fatty-acid chain bound to Acyl-carrier protein (ACP), a well-studied enzyme which binds to substrates of varying lengths. This protein-protein interaction 'broadens' the active site of these dehydrogenases thus, contributing to their flexible nature. This property is exploited for catalysing numerous chiral synthons, alkanes, long-chain alcohols and secondary metabolites in industries especially with FabG. FASI relegates FASII in eukaryotes making it a 'relic gene pool' and an antibacterial drug target with diverse inhibitor and substrate markush. FabG often substitutes other dehydrogenases for producing secondary metabolites in nature. This redundancy is probably due to gene duplication or addition events possibly making FabG, a progenitor to some of the complex short-chain dehydrogenases used in organisms and industries today.
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Affiliation(s)
- Anirudh P Shanbhag
- Department of Biophysics, Molecular Biology and Bioinformatics, University of Calcutta, Kolkata, 700009, India. .,Bugworks Research India Pvt. Ltd, C-CAMP, NCBS Campus, UAS-GKVK, Bellary Road, Bangalore, 560065, India.
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El Samak M, Solyman SM, Hanora A. Antimicrobial activity of bacteria isolated from Red Sea marine invertebrates. Biotechnol Rep (Amst) 2018; 19:e00275. [PMID: 30197871 PMCID: PMC6127373 DOI: 10.1016/j.btre.2018.e00275] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/25/2018] [Revised: 07/13/2018] [Accepted: 07/13/2018] [Indexed: 10/28/2022]
Abstract
Marine invertebrates-associated microorganisms were considered to be important sources of marine bioactive products. This study aims to isolate marine invertebrates associated bacteria with antimicrobial activity from the Red Sea and test their biosynthetic potential through the detection of PKS and NRPS gene clusters involved with the production of bioactive secondary metabolites. In this respect, fifty bacterial strains were isolated from eight different Red Sea marine invertebrates and screened for their antimicrobial activity against standard pathogenic bacteria (Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922, Bacillus subtilis ATCC 6633) and yeast (Candida albicans ATCC 10231) using the standard well diffusion assay. Five isolates showed antifungal activity against Candida albicans with no activity recorded against other pathogenic bacterial strains. On the other hand when these isolates were screened for the presence of biosynthetic gene clusters (PKS and NRPS) by PCR using five sets of degenerative primers, 60% of the isolates were shown to contain at least one type of PKS and NRPS gene clusters, which indicates the biosynthetic potential of these isolates even if the isolates didn't express any biological activity in vitro. Moreover the 16S rRNA molecular identification of the isolates reveal the biodiversity of the red sea marine invertebrates associated bacteria as they were found to belong to several bacterial groups present in Alphaproteobacteria, Gammaproteobacteria, Actinobacteria and Firmicutes.
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Affiliation(s)
| | | | - Amro Hanora
- Department of Microbiology & Immunology, College of Pharmacy, Suez Canal University, Ismailia, Egypt
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Li ZF, Zhu LP, Gu JY, Singh RP, Li YZ. Isolation and characterisation of the epothilone gene cluster with flanks from high alkalotolerant strain Sorangium cellulosum (So0157-2). World J Microbiol Biotechnol 2017; 33:137. [PMID: 28585173 DOI: 10.1007/s11274-017-2301-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Accepted: 05/26/2017] [Indexed: 01/12/2023]
Abstract
Epothilones are cytotoxic macrolactones having auspicious anti-tumorous activities, but merely produced by rare Sorangium strains. Here, we have focused on the epothilone gene cluster from special niche bacterial strain, S. cellulosum So0157-2. Therefore, we have isolated a high pH tolerant S. cellulosum strain So0157-2 and characterized the epothilones gene cluster and its flanks by cosmid/fosmid libraries preparation and sequencing. The assembly spanned 94,459 bp and consisted of 56,019 bp core region. Remarkably, the core as well as upstream 420 bp and downstream 315 bp were highly conserved, while further neighboring regions varied extremely. Transposase traces were identified near the core of clusters, supporting that the transposon-mediated transgenesis is a naturally evolved strategy for the cluster's dissemination. A predicted neighboring esterase gene was identified as a potential epothilone-resistance gene preventing self-toxicity. Novel modification or regulatory genes, a multi-position-cyclo releasing gene and their relationship with corresponding analogs were identified in strain So0157-2. These findings open the door to discover additional, naturally evolved epothilone-related genes for significant applications in industrial as well as clinical sector.
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Affiliation(s)
- Zhi-Feng Li
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, Jinan, 250100, China.
| | - Li-Ping Zhu
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, Jinan, 250100, China
| | - Jing-Yan Gu
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, Jinan, 250100, China
| | - Raghvendra Pratap Singh
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, Jinan, 250100, China
| | - Yue-Zhong Li
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, Jinan, 250100, China
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Nguyen HDT, McMullin DR, Ponomareva E, Riley R, Pomraning KR, Baker SE, Seifert KA. Ochratoxin A production by Penicillium thymicola. Fungal Biol 2016; 120:1041-1049. [PMID: 27521635 DOI: 10.1016/j.funbio.2016.04.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2016] [Revised: 04/04/2016] [Accepted: 04/04/2016] [Indexed: 10/21/2022]
Abstract
Ochratoxin A (OTA) is a mycotoxin produced by some Aspergillus and Penicillium species that grow on economically important agricultural crops and food products. OTA is classified as Group 2B carcinogen and is potently nephrotoxic, which is the basis for its regulation in some jurisdictions. Using high resolution mass spectroscopy, OTA and ochratoxin B (OTB) were detected in liquid culture extracts of Penicillium thymicola DAOMC 180753 isolated from Canadian cheddar cheese. The genome of this strain was sequenced, assembled and annotated to probe for putative genes involved in OTA biosynthesis. Known OTA biosynthetic genes from Penicillium verrucosum or Penicillium nordicum, two related Penicillium species that produce OTA, were not found in P. thymicola. However, a gene cluster containing a polyketide synthase (PKS) and PKS-nonribosomal peptide synthase (NRPS) hybrid encoding genes were located in the P. thymicola genome that showed a high degree of similarity to OTA biosynthetic enzymes of Aspergillus carbonarius and Aspergillus ochraceus. This is the first report of ochratoxin from P. thymicola and a new record of the species in Canada.
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Affiliation(s)
- Hai D T Nguyen
- University of Ottawa, Department of Biology, 30 Marie-Curie Private, Ottawa, ON, K1N 6N5, Canada; Agriculture and Agri-Food Canada, Ottawa Research and Development Centre, 960 Carling Avenue, Ottawa, ON, K1A 0C6, Canada.
| | - David R McMullin
- Carleton University, Department of Chemistry, 1125 Colonel By Drive, Ottawa, ON, K1S 5B6, Canada
| | - Ekaterina Ponomareva
- Agriculture and Agri-Food Canada, Ottawa Research and Development Centre, 960 Carling Avenue, Ottawa, ON, K1A 0C6, Canada
| | - Robert Riley
- US Department of Energy Joint Genome Institute, 2800 Mitchell Drive, Walnut Creek, CA, 94598, USA
| | - Kyle R Pomraning
- Pacific Northwest National Laboratory, Environmental Molecular Sciences Laboratory, Earth and Biological Sciences Directorate, 3335 Innovation Boulevard, Richland, WA, 99354, USA
| | - Scott E Baker
- Pacific Northwest National Laboratory, Environmental Molecular Sciences Laboratory, Earth and Biological Sciences Directorate, 3335 Innovation Boulevard, Richland, WA, 99354, USA
| | - Keith A Seifert
- University of Ottawa, Department of Biology, 30 Marie-Curie Private, Ottawa, ON, K1N 6N5, Canada; Agriculture and Agri-Food Canada, Ottawa Research and Development Centre, 960 Carling Avenue, Ottawa, ON, K1A 0C6, Canada
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Shimizu T, Ito T, Kanematsu S. Functional analysis of a melanin biosynthetic gene using RNAi-mediated gene silencing in Rosellinia necatrix. Fungal Biol 2014; 118:413-21. [PMID: 24742836 DOI: 10.1016/j.funbio.2014.02.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2013] [Revised: 02/21/2014] [Accepted: 02/28/2014] [Indexed: 11/16/2022]
Abstract
Rosellinia necatrix causes white root rot in a wide range of fruit trees and persists for extended periods as pseudosclerotia on root debris. However, the pathogenesis of this disease has yet to be clarified. The functions of endogeneous target genes have not been determined because of the inefficiency in genetic transformation. In this study, the function of a melanin biosynthetic gene was determined to examine its role in morphology and virulence. A polyketide synthase gene (termed as RnPKS1) in the R. necatrix genome is homologous to the 1,8-dihydroxynaphthalene (DHN) melanin biosynthetic gene of Colletotrichum lagenarium. Melanin-deficient strains of R. necatrix were obtained by RNA interference-mediated knockdown of RnPKS1. The virulence of these strains was not significantly reduced compared with the parental melanin-producing strain. However, knockdown strains failed to develop pseudosclerotia and were degraded sooner in soil than the parental strain. Microscopic observations of albino conidiomata produced by knockdown strains revealed that melanization is involved in synnema integrity. These results suggest that melanin is not necessary for R. necatrix pathogenesis but is involved in survival through morphogenesis. This is the first report on the functional analysis of an endogenous target gene in R. necatrix.
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Affiliation(s)
- Takeo Shimizu
- NARO Institute of Fruit Tree Science, Apple Research Division, 92-24 Nabeyashiki, Shimokuriyagawa, Morioka, Iwate 020-0123, Japan
| | - Tsutae Ito
- NARO Institute of Fruit Tree Science, Apple Research Division, 92-24 Nabeyashiki, Shimokuriyagawa, Morioka, Iwate 020-0123, Japan
| | - Satoko Kanematsu
- NARO Institute of Fruit Tree Science, Apple Research Division, 92-24 Nabeyashiki, Shimokuriyagawa, Morioka, Iwate 020-0123, Japan.
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