Abstract
BACKGROUND Simultaneous production of commercial enzymes using agro-industrial residues by statistical approach is an important perspective in an industrial point of view. Despite the advantages of statistical methods optimization, the report on simultaneous production of pectinase and amylases are limited. The accumulation of agro-industrial residues causes serious environmental problems; however, citrus peel can be the important substrate for various enzymes production, including pectinase. These enzymes involving saccharification process and act as clarifying agent.
RESULTS In this study, orange peel and banana peel mixture were used as the suitable substrate for pectinase and amylase production using Bacillus pumilus in solid-state culture. The process parameters were optimized for simultaneous production of enzymes by a traditional-one-variable-at-a-time approach, a two level full factorial design, central composite design and response surface methodology. Among the selected variables, moisture content of the medium, pH and mineral supplement significantly influenced pectinase and amylase production. Pectinase production increased over 3-fold, whereas, 2-fold increase on amylase production was achieved after optimization by statistical approach. The purified pectinase exhibited maximal activity at pH 8.0, temperature of 60 degrees C and the molecular weight was 60 kDa. The purified amylase was highly active at pH 8.0, at 50 degrees C and the molecular weight was 37 kDa. The enzyme showed activity on fruit pulp in increasing clarity in orange and carrot juice and the saccharification of starch.
CONCLUSION Orange peel and banana peel mixture was effective as a solid medium for the simultaneous production of pectinase and amylase by Bacillus pumilus. Also, our statistical approach to optimize the medium components to yield more pectinase and amylase was fruitful and these enzymes showed appreciable results suitable for various applications. (c) 2018 Society of Chemical Industry