Screening, Isolation and Characterization of Cellulolytic Bacteria from Agro-industrial Soils of Bangladesh and Their Optimization for Cellulase Enzyme Production
2021
Arrafy Rahman (Lecturer, Department of Microbiology, International Institute of Applied Science and Technology, Rangpur-5400, Bangladesh) | Md. Ahasun Habib (Lecturer, Department of Microbiology,International Institute of Applied Science and Technology, Rangpur-5400, Bangladesh and former MS student, Department of Biotechnology, Bangladesh Agricultural University, Mymensingh) | Sabina Yasmin (Professor, Department of Biotechnology, Bangladesh Agricultural University, Mymensingh 2202, Bangladesh) | Fahmida Khatun (Professor, Department of Biotechnology, Bangladesh Agricultural University, Mymensingh 2202, Bangladesh)
Cellulases are enzymes capable of degrading cellulose containing industrial pollutants. Nowadays, cellulase enzymes have a broad range of applications in different industries including textile, detergent, food and fermentation industries. In the present study, soil samples were collected from different agro-industrial regions of Bangladesh. Eighteen cellulolytic bacteria were isolated from the diluted soil samples.These bacterial isolates were preliminarily screened on Bushnell Haas medium (BHM) agar plate with the help of 0.3% congo red for the qualitative determination of cellulase activity where six isolates made the highest clearing zone around the bacterial colony. The highest clear zone forming bacterial isolate represented the highest cellulase activity. Different morphological (gram staining) and biochemical tests (catalase, indole, urease, oxidase, methyl red, Voges-Proskauer, gelatin hydrolysis, hydrogen sulfide, antibiotic sensitivity and carbohydrate including glucose, sucrose, lactose, xylose, sorbitol, mannitol and myo-inositol utilization tests) were performed to identify cellulolytic bacteria. Isolate 4, 6, 13 and 17 were identified as Streptococcus sp., Xanthomonas sp., Brucella sp. and Bacillus sp., respectively while isolate 1 and 9 were identified as Staphylococcus sp. In the present study, order (the highest to the lowest) of cellulase activity (U/mL) of bacterial isolate 13, 17, 6, 4 9, 1 was (1.85?0.05) > (1.56?0.07) > (1.26?0.06), (0.84?0.05) > (0.56?0.04) > (0.52?0.03) at their respective optimum temperature and pH. The findings of this study will help to identify other cellulolytic bacteria that can degrade cellulose containing soil pollutants. [J Bangladesh Agril Univ 2021; 19(2.000): 198-205]
显示更多 [+] 显示较少 [-]