Optimization of Carboxymethyl Cellulase Production by Bacillus sp. NAB37 and Biocatalytic Potential in Saccharification of Acid-Alkali Pretreated Parthenium Hysterophorus

The primary objective of this study was to assess the feasibility of using unconventional Parthenium hysterophorus weed biomass for the production of carboxymethyl cellulase using Bacillus sp. NAB37. The isolate NAB37 was identified by molecular characterization of 16SrDNA. Using P. hysterophorus as a substrate and submerged fermentation conditions in optimization studies helped strain NAB37 make more enzymes. Response surface methodology was applied to four independent variables chosen from the ‘one factor at a time’ approach for a comparison study. The central composite design was employed to evaluate the significant variables interacting outcomes. The maximum carboxymethyl cellulase production (5.38 U/ml) was obtained with a temperature of 40 °C (A), a pH of 7.5 (B), a substrate concentration of 3.0% w/v (C), and a starch concentration of 1.0% w/v (D). The alkali-acid-pretreated P. hysterophorus biomass was hydrolyzed using the crude enzyme produced under optimal conditions. On utilizing the cellulase enzyme for biomass hydrolysis, a maximum 32.78% saccharification yield (of cellulose, 0.364 g/g) was achieved in 96 h when enzyme and substrate levels were 30 FPU/100 ml and 2% (w/v), respectively. It is possible to hydrolyze P. hysterophorus biomass enzymatically, producing significant amounts of total reducing sugars. Thus, it can serve as a feedstock for the production of bioethanol.