Abstract

Halophilic bacteria are commonly found in natural environments containing significant concentration of NaCl. Two hundred halophilic bacteria were isolated. Among which, 63 strains were tested for the antimicrobial activity against 10 pathogenic bacteria, three yeast and nine pathogenic fungi. Of these isolates, only 12 strains showed activity against the test microorganisms, namely Pseudomonas aeruginosa, Serratia marcescens,Enterobacter cloacae, Staphylococcus aureus, Salmonella typhi, Klebsiella pneumoniae,Micrococcus luteus, Escherichia coli, Bacillus subtilis, Candida albicans, Colletotrichumgloeosporioides, Fusarium solani and Alternaria alternata. These 12 active isolates were identified to be of the genera, Streptomyces (seven strains), Microbacterium (one strain),Micrococcus (one strain), Bacillus (one strain), Planococcus (one strain) andMarinobacter (one strain). Seven strains were active against pathogenic bacteria and five strains against pathogenic fungi. Two strains SC-2 and SC-13 were found to have a broad spectrum of activity against all tested pathogenic bacteria and yeasts but not against pathogenic fungi. The strains SC-2 and SC-13 were closely related to Microbacterium oxydans (99%) and Streptomyces fradiae (99%) respectively. These findings show that the foreshore soil of Daecheon Beach and Saemangeum Sea of Korea represents an untapped source of bacterial biodiversity, and also that most actinobacterial isolates are capable of antibacterial and antifungal metabolite production.

Key words: Culturable diversity, halophilic bacteria, foreshore soil