Potential of Cellulase From Bacillus megaterium for Hydrolysis of Sargassum

Bacterial cellulase can be a promising biotechnological approach in seaweed degradation to facilitate extraction of bioactive molecules. In the present study, bacterial cultures were isolated from marine and terrestrial samples and screened for cellulase production. The selected cultures were grouped by random amplification of polymorphic DNA (RAPD) profiling, and the cultures showing a distinct banding pattern were identified by 16S rDNA sequence analysis. Cellulase from Bacillus megaterium (CB-sw1-I), a native isolate, was purified by ion-exchange chromatography with a purification fold of 6.91 and specific activity of 1.66 U. The purified enzyme with molecular weight of 43 kDa was optimally active at pH 6.0 and temperature of 60°C. The potentiality of enzyme in degradation of Sargassum thallus was evident with an increase in reducing sugar. Morphology of the thallus after 10 days digestion observed by scanning electron microscope also provided additional evidence for degrading ability of the enzyme. This enzyme could subsequently be used in hydrolysis of seaweed for extraction of bioactive molecules.