Effect of different growth parameters on endoglucanase enzyme activity by bacteria isolated from coir retting effluents of estuarine environment

Abstract

ABSTRACT:The cellulolytic enzyme-endoglucanase activity against coir fibre, a major biowaste by bacteria such as Cellulomonas, Bacillus and Micrococcus spp. isolated from coir retting effluents of estuarine environment was studied. The enzyme assay was carried out by using various concentrations (0.5 -2%) of substrate of coir powder as a carbohydrate in different pH (5 -9) and temperature (20 -50 °C). The enzyme activity was minimum in 0.5% substrate concentration at lower pH 5 (0.0087, 0.0143 and 0.0071 U/mL) and at 20 °C temperature (0.0151, 0.0154 and 0.0122 U/mL) by the bacterial strains such as Cellulomonas, Bacillus and Micrococcus spp respectively. Then this level was increased and reached maximum at the neutral pH (0.0172, 0.0165 and 0.0121 U/mL) and at 40 °C (0.0336, 0.0196 and 0.0152 U/mL) by the selected bacterial species. Further increase of pH and temperature, the enzyme activity reduced considerably to 0.0083, 0.0143 and 0.0037 U/mL at pH 9 and 0.0154, 0.0197 and 0.0121 U/mL at 50 °C by the tested bacterial strains.The same trend was also obtained in oth er substrate concentrations such as 1.0, 1.5 and 2.0 %. With in the four substrate concentrations, the endoglucanase enzyme activity was more in 1.5% concentration at the tested pH and temperatures. From the over all result, it was observed that, among the three bacterial strains, the enzyme activity was more in Cellulomonas sp, followed by Bacillus and Micrococcus spp. in varying pH and temperature.

Optimization of fermentation conditions for cellulase production by Bacillus subtilis CY5 and Bacillus circulans TP3 isolated from fish gut

“…Production started to decline after further increase in temperature. Immanuel et al (2006) also recorded maximum endoglucanase activity in Cellulomonas, Bacillus, and Micrococcus sp. at 40ºC at neutral pH.…”

“…In the present study, maximum cellulase activity was recorded between pH 7.0 and 7.5. Immanuel et al (2006) reported that the cellulolytic enzyme, endogluconase from Cellulomonas, Bacillus, and Micrococcus spp., isolated from estuarine coir netting effluents hydrolyzes substrate in the pH range of 4.0 to 9.0, with maximum activity at pH 7.0. The enzyme maintained its stability over a wide pH range (6.0 to 8.0), but had maximum activity at pH 7.0.…”

“…Cellulase yields appear to depend on a complex relationship involving a variety of factors like inoculum size (carbon source and cellulose quality), pH value, temperature, presence of inducers, medium additives, aeration, growth time, etc. (Immanuel et al 2006). Therefore, attention has been focused on studying the cellulolytic activity and cellulase enzyme production by several microorganisms in various products as well as in various environments.…”

“…An elaborate investigation is therefore, required to establish the optimum conditions to scale up enzyme production in an individual fermentation process. Although there are reports on the influence of various fermentation variables on cellulase production by different bacteria and fungi isolated from various natural environments (GarciaMartinez et al 1980, Stewart and Parry 1981, Coral et al 2002, Rajoka 2004, Immanuel et al 2006, information on the optimum fermentation conditions for cellulase production by fish gut bacteria is lacking. In the present investigation, the environmental and nutritional parameters for fermentation were optimized to enhance cellulase production by the bacterial strains B. subtilis CY5 and B. circulans TP3, isolated from the gut of common carp, Cyprinus carpio L., and Mozambique tilapia, Oreochromis mossambicus (Peters, 1852), respectively.…”

Biocatalysis of agro-processing waste by marine Streptomyces fungicidicus strain RPBS-A4 for cellulase production

“…This proves that the appropriate concentration is 0.6 g per 100 ml of fermentation medium. Similarly, Immanuel [11] was used coir fiber powder as the substrate for the generation of cellulase by bacteria. They found that maximum quantity of cellulase 0.081, 0.041, and 0.023 U/ml at 1.5% concentration of substrate.…”