ISOLATION AND SELECTION OF ACTINOMYCETES PRODUCING HIGH-BIOACTIVE SUBSTANCES

Abstract

Actinomycetes play an important role in the production of extracellular enzymes and secondary metabolic compounds with high biological activities. A total of 40 actinomycetes strains were isolated from soil samples of Ben Tre and Long An provinces. More than 50% of the actinomycetes strains were determined biosynthesis ability of one of four extracellular enzymes such as amylase, cellulase, protease and chitinase. Culture suspension of seventeen actinomycetes strains showed antagonistic activity against at least 1 of 4 tested bacterial strains such as Bacillus subtilis, Bacillus cereus, Escherichia coli, and Staphylococcus aureus. Moreover, 24 actinomycetes strains exhibited antifungal activity against at least 1 of 7 strains of plant pathogenic fungi such as Fusarium oxysporum, Fusarium equiseti, Neoscytalidium dimidiatum, Aspergillus sp., Aspergillus fumigatus, Colletotrichum siamence, and Penicillium chermesinum. The two strains CNXK 3 and CNXK 72 were identified to belong to the genus Amycolaptosis and Streptomyces, respectively. This study showed the potential of the application of metabolites from actinomycetes in industrial enzyme production, in biocontrol of pathogenic bacteria and pathogenic fungi as well as development of sustainable environment.