Being rich in lignocellulosic content, these can be used in production of many value added products such as enzymes, paper, paperboard, etc.
with simultaneous reduction in the environmental load.
Cellulase production also requires the development of a suitable bioprocess and the medium for fermentation constituting a cheap substrate such as wheat bran which is a low-cost agro-industrial residue.
Since the enzyme production from microbial source is a multivariable controlled process, it becomes essential to optimize the key factors i.e.
In order to achieve high titer of cellulase, a central composite design (CCD) was constructed and performed for optimization of SSF with five process variables at five coded levels.
A 2 full factorial design was constructed leading to a set of 50 experiments that were performed in triplicates.Typical examples of such sites from where the samples were collected include sludge from biogas plant, cow dung, degraded litter, degrading lignocellulosic biomass, soil from agricultural fields, sludge from paper mill, deteriorating sugarcane in soil, kitchen garden soil, decaying wood etc.All the samples collected were divided in two parts and one part of each was heat treated by keeping at 60 The microorganisms producing cellulase were isolated by Enrichment technique using 1% CMC (Carboxy Methyl Cellulose) based on the hypothesis that if the microorganisms are provided with cellulose as a sole carbon source in the medium for their growth, then only those who can produce cellulase enzyme to utilize cellulose for their growth and the metabolic needs could survive.The key variables namely incubation time, temperature, wheat bran and tap water ratio, p H and inoculum size were evaluated.The optimization of the process variables resulted in 1.14 IU/ml of cellulase activity from Bacillus subtilis PJK6 under SSF using wheat bran as a sole organic substrate with tap water.The enriched broth was again inoculated into 100 ml of 1% CMC and incubated under same conditions.This process was repeated 3-4 times and finally the microorganisms from the enriched broth were isolated by spread plate technique.Hence, response surface methodology (RSM) was applied as it is a useful statistical technique for analyzing the effect of several independent variables.A central composite design (CCD) was constructed to evaluate the interactive and mutual impact of the key variables on cellulase production with an objective to obtain high yields of cellulase in a cost effective and eco-friendly bioprocess.The economic production of valuable and useful enzyme using agricultural residue was achieved at moderate conditions from a GRAS microbe that can benefit the industry as well as the environment.This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.