Optimization and strain improvement by mutation for enhanced cellulase production by Bacillus sp. (MTCC10046) isolated from cow dung

Abstract

The goal was to investigate the cellulase enzyme production ability of bacterial strain C1 isolated from cow dung and identified as Bacillus sp. on the basis of 16 S rDNA sequence homology. The effects of different carbon sources like Carboxymethyl cellulose (CMC), avicel, starch, maltose, sucrose, glucose, fructose, galactose and lactose on cellulase production at varying environmental parameters of incubation period (2-10 days), temperature (35-55°C), and pH (6.0-8.5) were examined. The CMC was the best carbon source for cellulase production followed by lactose in this bacterial strain. The maximum enzyme production was achieved at a temperature of 50°C by Bacillus sp. with pH of 7.0 on the 8th day of growth. The nitrogen source NH 4 NO 3 at 0.175% was optimum for cellulase production by this bacterium. A putative mutant (C1M 26 ) was screened from wild C1 strain after mutagenesis with N-methyl-N 0 -nitro-N-nitrosoguanidine (NTG) as a mutagenic agent. The mutant C1M 26 produced a larger amount of cellulase in comparison to wild type C1 strain. ª 2014 Production and hosting by Elsevier B.V. on behalf of King Saud University.

Enhanced Cellulase Production by a Novel Thermophilic Bacillus licheniformis 2D55: Characterization and Application in Lignocellulosic Saccharification

“…This result could be due to alterations in the physical properties of the cell membrane or the repression of some proteins in the metabolic pathways (Sethi et al 2013). Sadhu et al (2014) reported that Bacillus sp. produced high amounts of cellulase at an optimum temperature of 50 °C.…”

“…A substrate concentration of 8% is optimal for cellulase production by Bacillus sp. at 50 °C (Sadhu et al 2014). A low substrate concentration increased the yield and reaction rate of hydrolysis; however, high substrate concentrations caused substrate inhibition and resulted in low enzyme formation (Liu and Yang 2007).…”

Screening Cellulolytic Bacteria from the Digestive Tract Snail (Achatina fulica) and Test the Ability of Cellulase Activity

“…In Here is a growth curve isolate bacteria KE-B6 based on the time of incubation (Figure 4 The growth curve above showed that the treatment time of 0-8 hours incubation showed an increase in the growth and classified into the logarithmic phase (log phase). This phase is formed because the bacteria undergo rapid cell Sadhu et al (2014), cellulase production of Bacillus sp best at age 8 hours (incubation period of 2-10 days). But, acccording to Yang et al (2014) examination of its growth characteristics Bacillus subtilis BY-2 showed that its growth curve entered the logarithmic phase after 8-12 h and the stable growth phase being between 20 and 40 h. This difference is caused by different types of bacteria used, as well as environmental conditions.…”

“…But, acccording to Yang et al (2014) examination of its growth characteristics Bacillus subtilis BY-2 showed that its growth curve entered the logarithmic phase after 8-12 h and the stable growth phase being between 20 and 40 h. This difference is caused by different types of bacteria used, as well as environmental conditions. In this phase of cellulase enzyme formed and are classified as primary metabolites (Madigan et al, 2009;Sadhu et al, 2014). In this phase, cell growth will happen very quickly and the production of enzymes increased (Johnsen and Kirsten, 2014).…”

“…Stationary phase occurs in the incubation time of 8-16 hours, where the absorbance values are stable or decreasing until the death phase. Sadhu et al (2014) stated that in the stationary phase number of cell willl be reduced because of depletion nutrients in the medium. Nutrients are compounds that play a role in the process of energy metabolism and physiology.…”