Studies on antimicrobial activity of actinomycete strains isolated from Majuli, a river island

Screening of actinomycete strains from different agro-ecological niches of river island Majuli was taken up to evaluate their antimicrobial potential against Ralstonia solanacearum, Xanthomonas axonopodis pv. citri, Bacillus subtilis, Proteus mirabilis, Escherichia coli, Rhizoctonia solani and Fusarium oxysporum. Out of 32 strains of actinomycetes, isolated from 50 different soil samples of Majuli, 12 showed antagonistic activity against one or more of the test organisms, while 5 strains were active against all. Among these five strains, a strain MJ 006 was found to be the best. The crude bio-active compound of the strain derived by using ethyl acetate at 1:1 ratio (v/v), had R_f values 0.09 and 0.25.