Identification of BSA B1 Bacteria and Its Potency of Purified Cellulase to Hydrolyze Chlorella zofingiensis

Abstract

Cellulase has been widely used as biocatalyst in industries. Production of cellulase from microorganisms has many advantages such as short production time and less expense. Our previous study indicated that one of cellulolytic bacteria from digestive tract of milkfish (Chanos chanos), namely BSA B1, showed the highest cellulase activity. The objective of this study was to determine the phylogenetic of BSA B1 strain using 16S rRNA gene sequence. Furthermore, this study also determine the specific activity of purified cellulase from BSA B1 strain and its potency to hydrolyze Chlorella zofingiensis cellulose. Cellulase was purified using ammonium sulphate precipitation, dialysis, and ion exchange chromatography. The purified cellulase was used to hydrolyze cellulose of C. zofingiensis. The result demonstrated that BSA B1 strain was closely related with Bacillus aerius and Bacillus licheniformis. The specific activity of the crude enzyme was 1.543 U mL-1; after dialysis was 4.384 U mL-1; and after chromatography was 7.543 U mL-1. Purified cellulase exhibited activity in hydrolyzed both CMC and C. zofingiensis. Compared to commercial cellulase, purified cellulase had lower activity in hydrolyzed CMC but higher activity in hydrolyzed C. zofingiensis. Ethanol dehydration could potentially increase the reducing sugar yield in cellulose hydrolysis when used appropriately. Morphology of C. zofingiensis cell has changed after incubation with cellulases and ethanol dehydration indicated degradation of cell wall.

Keywords

• cellulase
• enzyme purification
• cellulose hydrolysis
• BSA-B1