The study of bacteria cellulases isolated from the soil and possibilities of using different media for the formation of cellulases

Abstract

Enzymes cellulases are important because of their ability to decompose cellulose, which is a part of lignocellulosic biomass. It is possible to produce bioproducts and biofuels that are environmentally friendly using these enzymes. It is relevant to investigate cellulases produced by bacteria, which are found in air or soil. The aim of this work is to investigate the activity of cellulases produced by bacteria isolated from the soil and to determine the influence of fermentation conditions and different nutrient media on the growth of bacteria and the activity of cellulases produced by them. In the present work, we investigated bacteria, which were isolated from natural environmental sources. 43 bacteria isolates were isolated from the soil. It was found that six isolates showed cellulolytic activity. In addition, five different Bacillus sp. bacteria, which were isolated from the environment earlier, were tested. The highest cellulolytic activity was produced by B. subtilis 88. The influence of cultivation time, temperature and medium was studied. The highest cellulases activities were obtained in Nutrient broth with glucose (5 g l–1) at 30°C after 24 h of fermentation. In addition, molasses is a by-product of the sugar industry, which can be applied to cultivate bacteria belonging to Bacillus genus and produce bioproducts. In this work, cellulases activities of B. subtilis 88 after cultivation in the molasses medium were obtained similar or even higher compared with those of MRS and Nutrient broths.