Production of Cellulase and bioethanol by ethanol-tolerant coculture of Bacillus cereus and Fusarium solani

Abstract

Cellulase is an enzyme produced by fungi and bacteria that hydrolyzes cellulose by breaking down the glycosidic bond, β-1,4 that binds sugar glucose units. Bioethanol and cellulase enzyme were produced by ethanol-tolerant of Bacillus cereus co-culture. So the production of filamentous solani were using the wastes of Cynodon dactylon L. The highest activity of enzyme was at 96 hour/30°C of incubation. The optimal pH value was 7.5, while the carbon concentration was 3%. On the other hand, the best inoculum ratio was 0.5/100 mL (52 × 108 cell/mL bacterial cells and 105 conidia/mL of the fungus). In order to test the efficiency of ethanol production by the co-culture by using different concentrations of pure ethanol was measured in the solid medium. Both Bacillus sp. and F. solani tolerated incubation with 5% ethanol. The best treatment when using 0.5% sulfuric acid which gave the best concentration of reduced sugars and the results showed a difference in the concentration of sugars produced by the fermentation process, it was 3.9 mg/mL in the first day, whereas it was 2.51 mg/mL after 120 hours of fermentation, the concentration of bioethanol produced after fermentation was 195 g/L. In conclusion Cynodon dactylon L. wastes were treated by sulfuric acid, cellulase digestion, and autoclave treatment to be a good source of reducing sugars.