Prescreening of bioactivities from actinomycetes isolated from forest peat soil of Sarawak

Forest soil has been long regarded as a place for the isolation of rare and beneficial microorganisms such as actinomycetes. In this study, 40 isolates of actinomycetes were screened using multi-stage Dispersion and Differential Centrifugation (DDC) method. All the 40 isolates were later tested for their ability to secrete bioactivities such as cellulase, mannanase, xylanase, lipase, protease and antimicrobial compounds. Prescreening of the 40 isolates of actinomycetes showed that 45% produced cellulase, 5% mannanase, 12.5% xylanase, 12.5% protease and 32.5% lipase. It was observed that these actinomycetes also produced antimicrobial activities against various test pathogens such as Ralstonia solanacearum (10%), Pantoea stewartii (20%) and Bacillus subtilis (10%). Eight of the best producers of the bioactivities were identified using 16S rRNA primers binding to the 16S rRNA sequence of the microorganisms. Seven of the actinomycetes were identified to be from the genus Streptomyces while one was from the genus Kitasatosproria. These eight potential actinomycetes need further study to fully characterize their benefits before application in any industry.