Screening for antimicrobial activities from marine bacteria associated with the tunicate, didemnum molle

Abstract

From this study, bacteria from a tunicate collected in Bidong Island, Didernnurn mo/le, were isolated and screened for any antimicrobial activity. Out of 30 bacteria isolated on the Seawater Agars as mother plates, only 23 isolates survived on enriched media of Marine Nutrient Agars for isolation and maintenance phase. Out of 23 isolates, 69.6% (n= 16) of the isolates were observed as normal bacteria, while the rest of 30.4% (n=7) of the isolates were observed to be agar-hydrolyzing bacteria. 78.3% (n=18) of the isolates were found to be marine obligate bacteria, and the rest of 21. 7% of the isolates were facultative marine bacteria. Out of the 23 isolates screened for antimicrobial activity, only 8.70% of the isolates were found to have antimicrobial activity. These 2 isolates were characterized and identified using catalase test, oxidase test, Gram staining and API 20NE identification kit from Bio-Merieux TM to be Vibrio parahaernolyticus (Strain number 1) and Pseudomonas sp. (Strain number 8). These non-enterococci bacteria showed positive antimicrobial activity towards Staphylococcus agalactiae and Klebsiella pneumonia, respectively.