Production of antimicrobial compound from two potential actinomycetes SRM 2 and SD 17 using soluble and local starch

Fermentation of antimicrobial compound from two potential actinomycetes, SRM 2 and SD 17, has been carried out using a local carbon source and commercial soluble starch. Three local carbon sources, rice, corn, and tapioca starch were screened to determine the best local carbon source for growth medium of actinomycetes. Determination was based on Amylolytic Index Activity (AIA) using Iodine test. Result from screening local starch test of both actinomycetes SRM 2 dan SD 17 showed that rice starch was the best carbon source with AIA value (0.87 and 2.30) higher than corn starch (0.50 and 1.43) and tapioca starch (0.38 and 1.71). Antimicrobial compound of actinomycetes SRM 2 and SD 17 was produced in CSM medium containing soluble starch (CSMs) and rice starch (CSMb). Filtrate of the growth medium was tested for antimicrobial activity by using cylinder method against certain Gram positive and negative bacteria or yeasts. The results showed that filtrate of medium CSMs and CSMb from actinomycetes SRM 2 were most effective to inhibit Kocuria rhizophila with Antimicrobial Index (AI) 2.79 and 2.66, respectively. The filtrate was less effective against to Escherichia coli with AI 0.92 and 0.89. Filtrates of medium CSMs and CSMb from actinomycetes SD 17 were also most effective to inhibit K. rhizophila with AI 1.75 and 3.16 respectively. Meanwhile, the filtrates were less effective to inhibit Candida albicans with IA 0.67 for CSMs and 0.95 for CSMb, but not effective to inhibit Saccharomyces cerevisiae.