OBJECTIVETo isolate novel actinomycetes and to evaluate their antibacterial activity.

METHODSThree soil samples were collected from Vengodu (village) in Kanchipuram district, Tamil Nadu, India. Actinomycetes were isolated using serial dilution and plating method on actinomycetes isolation agar.

RESULTSTotally 35 isolates were obtained on the basis of colony characteristics on actinomycetes isolation agar. All the isolates were screened for antibacterial activity by cross streak method. Medium and optimization of day were done for the potent strains using Nathan's agar well diffusion method. Isolation of bioactive compounds from significant active isolates was done by using different media. The most active isolate VAS 10 was identified as Actinobacterium Loyola PBT VAS 10 (accession No. JF501398) using 16s rRNA sequence method. The hexane, ethyl acetate, dichloromethane and butanol extracts of VAS 10 were tested against bacteria. The maximum antibacterial activity was observed in dichloromethane and ethyl acetate; maximum zones of inhibition were observed against Enterococcus durans. The rRNA secondary structure and the restriction sites of Actinobacterium Loyola VAS 10 were predicted using Genebee and NEBCutter online tools respectively.

CONCLUSIONSThe present study showed that among the isolated actinomycetes, Actinobacterium Loyola PBT VAS 10 (accession No. JF501398) showed good antibacterial activity against the tested bacteria.

Actinobacteria ; chemistry ; isolation & purification ; physiology ; Animals ; Anti-Bacterial Agents ; pharmacology ; Antibiosis ; physiology ; Bacillus subtilis ; drug effects ; Enterobacter aerogenes ; drug effects ; Escherichia coli ; drug effects ; India ; Microbial Sensitivity Tests ; Phylogeny ; RNA, Ribosomal, 16S ; genetics ; Soil Microbiology ; Species Specificity ; Vibrio parahaemolyticus ; drug effects