Study On The Production Of Ethanol From Jerusalem Artichoke

The study mainly investigated the effects of the mutagenesis, conditions of nutrition and culture on inulinase production by Aspergillus niger. Ethanol fermentation from Jersulem artichoke using Aspergillus niger SL-09 and Saccharomyces cerevisiae Z-06 was also studied.Aspergillus niger SL-08 was treated by ultraviolet (UV) and nitrosoguanidine (NTG). The results showed that they got different effects on strain SL-08. Aspergillus niger SL-08 can dramatically improve the character of Saccharomyces cerevisiae.Z-06 with respect to the activity of fermentation and the ethanol tolerance.Subjected by UV and NTG mutagenesis, Aspergillus niger SL-09 was isolated, and the enzyme activities were enhanced 2 times higher than the original strain. Flask liquid-state fermentation experiments were carried out. The results showed that the carbon source, nitrogen source, surfactants and the medium pH affected the production of inulinase significantly, and the optimum condition for enzyme production obtained was: Jerusalem artichoke flour 50g/L, soybean flour 40g/L, sucrose ester 6g/L and pH6.0. It was also interesting to find that inulinase is an inducible enzyme, meanwhile, the sucrose ester, acts as an effective accelerant, enhanced the enzyme activities in the medium using glucose as carbon source to150IU/mL and 300IU/mL for exoinulinase and endoinulinase respectively.As a result, 19.6% (V/V) of ethanol was produced from Jerusalem artichoke flour within 60h of fermentation by simultaneous saccharification and fermentation using Aspergillus niger SL-09 and Saccharomyces cerevisiae. Z-06 at 30℃, and the conversion efficiency of the Jerusalem artichoke to ethanol was 90% of the theoretical ethanol yield.