Purification and characterization of cellulase from a marine Bacillus sp. H1666: A potential agent for single step saccharification of seaweed biomass

Abstract

• Marine bacterium Bacillus sp. utilized without prior treated agricultural waste. • Cellulase production by Bacillus sp. in single step from wheat straw/rice bran. • Cellulase: molecular mass of 40 kDa, thermo-stable and active at wide pH 3–9. • High saccharification efficacy as tested on seaweed Ulva . In this study, 115 marine bacterial isolates were screened for cellulase enzymatic activity and enzyme with a molecular mass of 40 kDa was purified from culture supernatant of the marine bacterium Bacillus sp. H1666 using ion exchange and size exclusion chromatography method. Growth of bacterial strain H1666 with efficient cellulase enzyme production was observed on untreated wheat straw and rice bran. The biochemical properties of the extracted cellulase were studied and enzyme was found active over a range of pH 3–9. The optimum cellulase activity was observed at pH 7 and temperature 50 °C. The enzyme was also shown to be slightly thermo-stable with 40% residual activity at 60 °C for 4 h. The potential applicability of enzyme was tested on dried green seaweed ( Ulva lactuca ) and 450 mg/g increase in glucose yield was obtained after saccharification. MALDI TOF–TOF analysis of cellulase peptide fingerprint showed similarity to the sequence of the glycoside hydrolase family protein.