Sharma, A.KHeena Prakash2018-07-302018-07-302017-07http://krishikosh.egranth.ac.in/handle/1/5810062489Use of cheap lignocellulosic biomass, such as banana peels, for bioethanol production, can simultaneously provide a solution to the major key global issues of the energy crisis and environmental pollution. In present study, the possibility of using waste banana peels for the production of ethanol has been investigated. To minimize the cost of ethanol production using enzymatic hydrolysis, the hydrolytic enzymes that are necessary for cellulose and hemicelluloses hydrolysis were produced in-house using a bacterial strain, Geobacillus stearothermophilus HPA19, isolated from an alkaline soil sample. The bacterium was able to produce cocktail of the thermo-alkali-stable xylano-cellulo-pectino enzymes using wheat bran (an agro-residue) as carbon source within 24 h peroid. These enzymes showed excellent stability at high temperature (80 ºC) and pH (10.0). The optimal temperature and pH for xylanase, FPase, pectinase are 80, 70, 80 ºC and 9.0, 8.0, 9.0, respectively. The metal ions Ni+2, Zn+2 promoted the relative activities of xylanase and FPase whereas Na+, Ca+2 and K+ promoted pectinase activity in the enzymes cocktail. After that application of this cocktail was assessed in the saccharification of banana peel. Reducing sugar obtained (37.06 mg/ml) after OVAT method is greatly influenced by enzyme dose [ratio 1:1:2], substrate concentration (10.0%), hydrolysis time (1 h) and hydrolysis temperature (70 ºC). Further Response Surface Methodology (CCD) was used to optimize saccharification. This led to a 2 fold increase in reducing sugar (54.14 mg/ml) giving a high saccharification efficiency of 54.14%. Under the optimum conditions of saccharification, ethanol was produced using yeast which gives highest ethanol production of 21.10 g/l and fermentation efficiency of 76.50% within 30 h. Thus, the study presented proved to be a comprehensive study, where in-house enzymes cocktail by a thermophilic bacteria G. stearothermophilus HPA19 was produced for bioconversion of banana peels into second generation bioethanol.ennullThesis