Department of Microbiology, St. Thomas College, Bhilai, Chhattisgarh, India
Background: Plant biomass and agricultural waste products disposal is a serious problem in agriculture based countries. These wastes, usually rich in xylan can be satisfactorily converted to industrially important and useful products by efficient biotechnological application of potent xylanase producing bacteria which generally have high temperature and pH optima.
Objective: The aim was to isolate and identify xylanolytic bacterial isolates from Bhilai-Durg region of Chhattisgarh, India which was otherwise unexplored for isolation of thermoalkalophilic xylanase producing bacteria. Partial scale up of process development was performed.
Materials and Methods: Xyalanse producing bacteria were isolated from probable samples following three stages of screening procedures. The potent isolates were identified and various parameters affecting xylanase production were optimized using the conventional one-factor-at-a-time approach.
Results: Two potent indigenous bacterial isolates belonged to genus Bacillus and designated as Bacillus sp. MCC2728 and Bacillus sp. MCC2727 were isolated from forest soils with the ability to degrade xylan. Significant differences were observed in their morphology and phenotypic characters amongst themselves and with its closest type strains implying the novelty of the two isolates. After optimization, maximum xylanase levels were obtained at pH 9.0, 55 °C for Bacillus sp. MCC2728 and 50 °C for Bacillus sp. MCC2727, 5% inoculum, agitation speed (150 rpm). Yeast extract and peptone are best nitrogen sources and wheat bran, the best carbon source. The GenBank/EMBL/DDBJ accession numbers of strains Bacillus sp. MCC2728 and Bacillus sp. MCC2727 are KP742971 and KT444621 respectively. Wheat bran, Yeast extract and peptone proved to be the best carbon and nitrogen sources respectively and xylose as an additive was found to be contributing to maximize the xylanase yields.
Conclusion: Two potent thermoalkalophilic novel bacterial isolates were successfully isolated with xylan degrading ability which may be used as promising xylanase producing candidates for various industrial purposes using agricultural based waste residues.