Isolation and Screening of Cellulolytic Microflora from Soil Polluted with Cotton

Author Name: Y.Koteswara rao,L.Srinivas naik, *K.Ravichandra
Author Email: ravichandrabio@gmail.com

Abstract

Cotton the white gold of our country has its high yield in the regions of AP. The Industrial wastes of these cotton industries are of high solid powder content and are rich in cellulose, which is often dumped as such into the soil. This soil containing cotton wastes is a good source for a variety of cellulolytic bacteria. The current study uses this cellulose containing soil as a source to isolate the cellulolytic bacteria. Initial isolation was performed using CMC congo red agar medium. Out of the 15 colonies observed one of the most prominent colonies was collected and purified by streak plate method to give single organism isolates. Degradation zones were identified on the CMC medium and were denoted as R-1. According to morphological and bio-chemical tests the organism is identified as Bacillus sps., which was grown on different cellulostic media viz., CMC, Cellulose powder and Cellobiose for different incubation times. Effect of incubation time for the above mentioned substrates on cellulolytic activity was studied by comparing diameters of lysis zones, which are considered as a measure of cellulolytic efficiency. Maximum cellulolytic activity was observed in cellobiose substrate at 0.2% conc., on 12th day of incubation.

Introduction

Cellulose is a major carbohydrate polymer that consists of a long unbranched chain of glucose units. Cellulose is the most abundant component of plant biomass is found in nature exclusively in plant cell walls, although it is produced by some animals (e.g. tunicates) and a few bacteria (Lynd et al., 2002). In the most cases, cellulose fibrils present in plant cell walls are embedded in a matrix of hemicelluloses and lignin. Cotton waste is a good source of cellulose and can be utilized for cellulosic ethanol production. “cotton waste” includes the droppings, strippings, fly and other waste products of a cotton mill or of a cotton ginning factory or cotton pressing factory but does not include yarn waste. The cellulolytic organisms whose major source of food is cellulose would invade on the cellulose and persist in the waste. Cellulolytic microorganisms are abundant in nature and play important role in the carbon cycle by recycling CO2 fixed by photosynthesis. It is likely that they are evolved with the appearance of cellulose in plants. Indeed, it is conceivable that some cellulose genes were actually borrowed from plants, in which they appear to play a role in morphogenesis and developmental processes (e.g., in the ripening of fruits such as avocado).
Cellulose degradation occurs in a variety of ecological niches where plant residues accumulate. Thus, cellulolytic microorganisms include a variety of aerobes and anaerobes, mesophiles, and thermophiles. As a general rule, cellulolytic microorganisms found in natural habitats constitute mixed populations, including several cellulolytic and non cellulolytic species, which interact synergistically. These interactions, lead to efficient cellulose degradation with formation of CO2 and H2O in aerobiosis or CO2, CH4, and H2O in aerobiosis. The current work involves the use of cotton industrial effluents as a major source for the isolation of those organisms that are capable of the cellulose degradation. Once the organisms are identified, they can be later employed for various commercial purposes.

Conclusion

Cotton industrial effluents soil is rich in cellulosic materials that favored the growth and diversity of cellulolytic micro flora as per properties of tested samples. In the present study cellulolytic bacteria was isolated from cotton industry effluent soil samples. Biochemical tests revealed that the isolated cellulolytic strains belong to Bacillus sps according to Bergy’s manual of systematic bacteriology. As per the colony size and hydrolytic zone diameters the isolates were primarily observed as efficient cellulolytic bacteria. Further study is needed to evaluate the cellulolytic potential by growing in various production media on large scale in addition to biochemical characterization of extracellular cellulase enzymes produced by the isolated bacterial strain.

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