Statistical media optimization and cellulase production from marine Bacillus VITRKHB.

Kunal Singh,Gaurav Kumar,Loganathan Karthik,Kumari Richa,Kokati Venkata Bhaskara Rao,Himadri Bose

doi:10.1007/s13205-013-0173-x

Abstract

Marine Bacillus species are potent producers of novel enzymes. Marine Bacillus VITRKHB was observed to be efficient for cellulolytic activity. It was employed for the production of extracellular cellulase. Cellulase was partially purified to 1.6-fold in a stepwise manner by ammonium sulfate precipitation, dialysis, and DEAE ion exchange chromatography. The molecular weight of purified protein was found to be about 33 kDa by SDS-PAGE. Its specific activity was recorded as 1.92 IU/mg. The effect of various carbon and nitrogen sources on cellulase production was investigated. The maximum enzyme activity was recorded in the fermentation media containing xylose as carbon source and beef extract as nitrogen source. The combined interactive effect of different variables on cellulase production was studied by response surface methodology. The optimized combination of variables for maximum enzyme activity was determined as; xylose 5.0 %, beef extract 6.9 %, pH 7.83, NaCl 1.17, and temperature 25.84 °C, after 24 h of incubation.

Highlights

Cellulases are a class of enzymes primarily responsible for hydrolysis of cellulose into b-glucose
The combined interactive effect of different variables on cellulase production was studied by response surface methodology
The Bacillus VITRKHB was screened for cellulolytic activity by growing it on a carboxy methyl cellulose (CMC) agar plate for 24 h at 37 °C

Summary

Introduction

Cellulases are a class of enzymes primarily responsible for hydrolysis of cellulose into b-glucose. (Mukhopadhyay et al 2008) This is a time-consuming process and does not explain the combined interactive effect of parameters involved with the fermentation process. To overcome these limitations, different initiatives have been undertaken. Optimization of the process parameters affecting fermentation by statistically designed experimental strategies is an easy and rapid process One such method is response surface methodology (RSM).

Materials and methods

Results and discussion

Conclusion