|
Crop straw cellulose new energy through photosynthesis, C02 and H20 fixed in solar crop body, is an inexpensive and widely available a new type of biomass energy. Straw, wheat, corn three main straw, rice straw containing waxy due to plants with higher degrees of polymerization of the cellulose, and more difficult to degrade. 2 degrading rice straw cellulose better microbial strains bred from the natural decay of straw, optimized strains by protoplast fusion and its application of fermentation alcohol, has been following three main outcomes: (1) from Hunan Agricultural University experimental fields and Liuyang river rot screened 126 fungal strains isolated rice straw, and 10 degradation of rice straw better strains screened, Number as follows: A242, B321 , A211, A111, A321, B521, A251, A232, B711 and B311, A242, A251 No. strains which can be effective degradation of cellulose in rice straw; A321, B311 No. strain can be effective degradation of rice straw hemicellulose . A242, B311 strains of rice straw fermentation degradation reducing sugar content in the liquid can to reach 94.1044mg / g respectively 90.6274mg / g straw powder, more than the control strain 78.9692mg / g; degradation of the A321, B321 strains straw fermentation of xylose content in liquid respectively can be achieved 11.8210mg / g, 12.1219mg / g straw powder, the over control strains 11.1689mg / g. Preliminary identification of the A242 strain similar imperfect the Penicillium fungi Cong Terrier spore head Cong Terrier spore Division Aspergillus family several rounds of Penicillium; B321 strain similar to algae bacteria Gang Mucorales the Mucoraceae Mucor racemosus Mucor circinelloides; A321 similar of imperfect mushrooms Cong Terrier the spore head Plexus Terrier Aspergillus spores subjects the family Aspergillus smoked Aspergillus. (2) In order to improve the strains of straw degradation the protoplast fusion breeding superior strains of screening. A242 and A321 strain as the parent strain, after protoplast fusion breeding, the screened strain 1-2-3 degradation straw cellulose, hemicellulose, for reducing sugar capacity and xylose ability has improved significantly, the straw degradation solution reducing sugar, the xylose content reached 0.7712mg/mL 0.0902mg/mL. (3) degrading strains by protoplast fusion get excellent straw fermentation conditions were optimized. Straw powder directly as a fermentation substrate, optimization analysis of inorganic salts, inorganic nitrogen, the temperature and fermentation time, and eventually obtain the optimum fermentation conditions were as follows: 0.3% of cobalt chloride, 0.5% ammonium sulfate at 30 ℃ after fermentation 108h, straw degradation liquid reducing sugar content up to 2.2712mg/mL. Application of rice straw fermentation trials found that simultaneous vaccination of straw fiber degrading bacteria and xylose fermentation yeast rice straw fermentation the result is not satisfactory; the first vaccination fiber degrading bacteria for degradation, raise the temperature to 48 ℃ for enzyme enzymatic 10h after inoculation xylose fermentation yeast fermentation to ethanol production, can achieve good results, alcohol rate of 0.13g / g straw powder.
|