Biodegradation and bioconversion of cellulose containing waste using bacterial and fungal consortium

Abstract

In this paper, the results of study of the cellulose biodegradation using cellulolytic microorganisms are given. Aspergillus awamori VUDT-2, Bacillus subtilis 82 and consortium consisted of named strains were used in the enzymatic hydrolysis. Morphological features of these microorganisms were described using optical microscopy and by inoculation of suspensions on meat peptone agar. Initially, cellulose-degrading activity of microorganisms was tested in the medium containing reagent grade cellulose. The cultivation was carried out on a shaker-incubator in 750 mL Erlenmeyer flasks at a temperature of 30 °C and a stirring speed of 200 rpm for 6 days. As a result, the consortium showed better cellulolytic activity and 49.2 % of total cellulose was degraded in the end of the experiment. Then, the growth conditions of the consortium were optimized in terms of temperature, stirring speed and the initial pH of the medium. For further experiments, the dried distillers grains with solubles (DDGS) after alcohol production was used as a source of cellulose-containing waste. The content of the cellulose in the DDGS is 20.78 %. Under the conditions of temperature 30 °C and the stirring speed at 200 rpm the biodegradation level of cellulose using consortium of cellulolytic microorganisms was 70.24 % after 6 days.