Isolation and identification of bacteria with cellulose-degrading potential from soil and optimization of cellulase production

Abstract

Soil is one of the most promising sources for the presence of a variety of microorganisms which produce different hydrolytic enzymes. Such microorganisms include bacteria, fungi, etc. The ability to produce hydrolytic enzymes makes them potential candidates for hydrolysis of complex polymeric substrates. The present study aims at screening, isolating, and characterizing cellulolytic bacteria isolated from soil samples. Nine different soil samples were collected from different locations near Raigad district, Maharashtra, India. Carboxymethylcellulose (CMC) was used as a sole source of carbon for screening of cellulase-producing isolates. Forty-five different cellulase-producing bacteria were isolated based on their ability to decolorize Congo red and iodine. The morphological and molecular characterization of seven best isolates was carried out for their identification. All seven isolates were identified to be Bacillus species using 16s rRNA gene-based sequencing. The optimization of cellulase enzyme production of these seven isolates was carried out by using different parameters such as pH, temperature, and carbon sources. Majority of the cellulase producers identified in the present research work were found to be mesophiles. pH ranging from 6 to 8 was found to be most suitable to produce cellulase enzyme by the isolates. The data suggest that polymeric substances such as starch and CMC act as inducers for cellulase production.