ABSTRACT
Aims: The aims of this study were to screen for cellulose degradation activity from actinomycetes using agar plate method, detect β-glucosidase activity, morphology and molecular taxonomy study. Methodology and results: Preliminary screening for cellulose degrading Actinomycete was done on the carboxymethyl cellulose agar (CMC agar) and detected by flooding with gram iodine. It was found that 190 isolates were cellulase producing actinomycetes. Actinomycete isolate CDF2L1D13 showed maximum clear zone around the colony and the highest hydrolysis capacity value was 3.93. β-glucosidase activity was examined by measuring the amount of paranitrophenol (pNP) librated by Tako method. Study on comparison of the enzyme activity in CMC broth with alternative broth was performed. The highest β-glucosidase activity was found on alternative production medium that supplemented rice bran as a carbon source. β-glucosidase activity was 0.401 U/mL. The optimum pH of alternative production medium for producing β-glucosidase was at pH value 7 and incubated at 30 °C. Isolate CDF2L1D13 was antagonistic actinomycete against rice blast pathogen (Pyricularia oryzae). The character of this isolate was showed white color of substrate mycelium, white color of aerial mycelium, gray spore and spiral spore chain. Actinomycete isolate CDF2L1D13 was phylogenetically similar to Streptomyces osmaniensis. Conclusion, significance and impact of study: The result from this study indicated that Streptomyces osmaniensis has the potential on β-glucosidase production and it is antagonistic actinomycete against Pyricularia oryzae.