title: Diversity and antimicrobial activities of actinobacteria isolated from tropical mangrove sediments in Malaysia.
abstract: The aim of this study was to isolate and identify Actinobacteria from Malaysia mangrove forest and screen them for production of antimicrobial secondary metabolites. Eighty-seven isolates were isolated from soil samples collected at 4 different sites. This is the first report to describe the isolation of Streptomyces, Mycobacterium, Leifsonia, Microbacterium, Sinomonas, Nocardia, Terrabacter, Streptacidiphilus, Micromonospora, Gordonia, and Nocardioides from mangrove in east coast of Malaysia. Of 87 isolates, at least 5 isolates are considered as putative novel taxa. Nine Streptomyces sp. isolates were producing potent antimicrobial secondary metabolites, indicating that Streptomyces isolates are providing high quality metabolites for drug discovery purposes. The discovery of a novel species, Streptomyces pluripotens sp. nov. MUSC 135(T) that produced potent secondary metabolites inhibiting the growth of MRSA, had provided promising metabolites for drug discovery research. The biosynthetic potential of 87 isolates was investigated by the detection of polyketide synthetase (PKS) and nonribosomal polyketide synthetase (NRPS) genes, the hallmarks of secondary metabolites production. Results showed that many isolates were positive for PKS-I (19.5%), PKS-II (42.5%), and NRPS (5.7%) genes, indicating that mangrove Actinobacteria have significant biosynthetic potential. Our results highlighted that mangrove environment represented a rich reservoir for isolation of Actinobacteria, which are potential sources for discovery of antimicrobial secondary metabolites.
authors.affiliation: Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, 46150 Bandar Sunway, Selangor Darul Ehsan, Malaysia.
authors.forename: Learn-Han
authors.initials: LH
authors.lastname: Lee
authors.affiliation: Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, 46150 Bandar Sunway, Selangor Darul Ehsan, Malaysia ; Division of Genetics and Molecular Biology, Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia.
authors.forename: Nurullhudda
authors.initials: N
authors.lastname: Zainal
authors.affiliation: Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, 46150 Bandar Sunway, Selangor Darul Ehsan, Malaysia.
authors.forename: Adzzie-Shazleen
authors.initials: AS
authors.lastname: Azman
authors.affiliation: Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, 46150 Bandar Sunway, Selangor Darul Ehsan, Malaysia ; School of Science, Monash University Malaysia, 46150 Bandar Sunway, Selangor Darul Ehsan, Malaysia.
authors.forename: Shu-Kee
authors.initials: SK
authors.lastname: Eng
authors.affiliation: Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, 46150 Bandar Sunway, Selangor Darul Ehsan, Malaysia.
authors.forename: Bey-Hing
authors.initials: BH
authors.lastname: Goh
authors.affiliation: Division of Genetics and Molecular Biology, Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia.
authors.forename: Wai-Fong
authors.initials: WF
authors.lastname: Yin
authors.affiliation: UKM Medical Molecular Biology Institute (UMBI), UKM Medical Centre, Bandar Tun Razak, 56000 Cheras, Kuala Lumpur, Malaysia.
authors.forename: Nurul-Syakima
authors.initials: NS
authors.lastname: Ab Mutalib
authors.affiliation: Division of Genetics and Molecular Biology, Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia.
authors.forename: Kok-Gan
authors.initials: KG
authors.lastname: Chan
mesh_terms: D039903:Actinobacteria / Q000145:classification / Q000302:isolation & purification / Q000378:metabolism*; D000890:Anti-Infective Agents / Q000302:isolation & purification / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects; D044822:Biodiversity; D055808:Drug Discovery; D019015:Geologic Sediments / Q000382:microbiology*; D008296:Malaysia; D008826:Microbial Sensitivity Tests; D010802:Phylogeny; D053833:Wetlands
chemical_list: D000890:Anti-Infective Agents