Enzymatic Hydrolysis Of Industrial Fiber Waste Residue For Ethanol Production Technology

It is economic and environmental to produce ethanol from cellulose, which is the most abundant regenerated resources in the world. Cellulosic saccharification and ethanol fermentation are two important research parts in the bioconversion of cellulose to ethanol currently. This research was about the breeding ofβ-glucosidase-producing strains, the optimum condition of SSF for enhancing hydrolytic efficiency and ethanol yield and the mix-cultured of Penicillium decumbens JU-A10 with Aspergillus aculeatus L22.1) NIP35,theβ-glucosidase high-yield strain, was obtained through N⁺ implanting into Aspergillus aculeatus L22. The yield increased 1 fold than that of the original. The culturing conditions such as carbon source, nitrogen source, and surfactant effect on fermentation of NIP35 were studied. Under the optimum condition, 3% corn cob residue, 3% wheat bran, 0.5% (NH₄)₂SO₄, 0.3% CaCO₃, 0.5% KH₂PO₄ , 0.05%MgSO₄, 0.2% Tween-80, incubated under 30℃, 200rpm,for 5 days, the yield ofβ-glucosidase increased to 16. 24 IU/ml, nearly 2 folds of the original strain.2) We optimized the SSF condition of JU-A10 and NIP35 via gradual tests of temperature, yeast inoculation, the ratio of substrate to fluid , enzyme concentration and the effect of surfactant. The best condition is SSF with 20 IU/g enzyme concentration, the ratio of substrate to fluid is 1:10, 0.2% Tween-80,using 0.2% yeast inoculation in 37℃. We also researched on the co-fermentation of corn cob residue and cornstarch. The optimization provide important value for bioethanol industry progress.3) In order to simplify the technics,we also optimized the condition of JU-A10 mix-cultured with L22. For the difference of two genus, the growth ratio and composition of medium are also different.The result shows it is hard to culture the two strains together,we did not get a satisfactory result.