Screening of antimicrobial properties from marine bacteria associated with sea cucumbers (stichopus chloronotus and holothuria edulis) in Bidong water Terengganu

Abstract

This study was conducted in advance to isolate, screen and characterize marine bacteria from specified species of sea cucumber which possess antimicrobial properties. The source of marine bacteria in this study is from the stomach and body cavity of each sea cucumber's species which was collected in Bidong water. Four initial bacteria plates were prepared from the samples and it was maintained and cultured in SW A agar. A total of 228 pure colonies bacteria were isolated but only approximately 100 bacteria was used for further study. Only 73 bacteria were successfully maintained and transferred to MNA agar a week before screening. The method used for the screening was Modified Agar Disc Diffusion Method where the cultured bacteria were transferred onto target bacteria agar and the activity was observed in 24 hour incubation. There are six target bacteria used in this study which are Aeromonas hydrophila, Bacillus subtillis, Candida albicans, Klebsiella pneumoniae, Streptococcus agalactia, and Staphylococcus aureus. 62 bacteria show positive bioactivites but 3 were unable to be maintained for biochemical test. There were 40 gram negative bacteria with only 2 oxidase negative bacteria and the other 38 was oxidase positive. These bacteria were characterized and identified by using API 20E and API 20NE respectively. The oxidase negative gram negative bacteria were both identified as S. maltophilia. The oxidase positive bacteria identified comprise of Acinetobacter sp.(l ), Aeromonas sp.(4), Burkholderia sp.(4), Chryseobacterium sp.(1 ), Pseudomonas sp.(2), Stenotrophomonas sp.(2), Vibrio sp.(21) and 3 unidentified species.All 19 gram positive tested were rods. From selected biochemical tests done, bacteria were identified from the Corynebacterium sp.(9) and Bscillus sp.(l 0).