Optimised production of chitinase from a novel mangrove isolate, Bacillus pumilus MCB-7 using response surface methodology

Chitinases – the primary chitin lytic enzyme has gained great attention due to its industrial, environmental, agriculture, medicinal and biotechnological applications. However, the industrial production of this enzyme is still at its infancy due to low yielding strains and high cost of production. The current paper targets the cumulative optimisation of chitinase production from low cost substrate chitin using high yielding novel chitinase producing strain. Bacterial chitinase producers were isolated from the potential mangrove ecosystem of Valanthakad, Cochin, Kerala. Among the various isolates, the best chitinase producer MCB-7 identified as Bacillus pumilus exhibited an inherent high chitinase activity of 3.36 U/mL. Using Plackett–Burman design the factors such as chitin concentration, peptone and pH were found to be significant. Further optimisation with a multivariate statistical approach using Box–Behnken design resulted in a 6.9 fold increase of chitinase activity to a final yield of 23.19 U/mL. The use of cheap and consistent nature of the chitin as carbon source along with a high chitinase yielding isolate would be beneficial in providing consistent yields of the enzyme. To the best of our knowledge, this is the first report on high chitinase yielding B. pumilus strains from mangroves. The current isolate of B. pumilus MCB-7 is also unique in its halotolerance, pH tolerance and thermostability – which could widen its spectrum of applications.