The Foundation Of The Compound Microbial Fermentation On Oil Plants Straw And Primary Application

Cole is one important of oil crops especially in middle and lower reaches of Yangzi River.Rapeseed yield reach 11 million tons and produce 15 million cole straw.The crops straw is an important biological resource. But straw contains large quantities of lignocelluloses that the structural is stability and hardly degraded. At present most degradation used are physics and chemical methods cannot degrade effectively and brings the cost and the environment questions. The biological treatment of straw is deemed to be the best method, because this treatment has many advantages, such as low pollution, high efficiency and the used condition is temperate. Biological treatment has great potential in degenerating lignocelluloses. But microorganism's characteristic has also limited its application such as the natural degrading lignocelluloses'microorganism mostly degrades time too long and easily influenced by external environment. In the long-term experiments and production practice, people found that the straw degradation was accomplished by a series of enzymes produced in the microbial metabolism process. These enzymes need to have a synergistic effect on the degradation of straw. The single enzyme has low degradation ability; nevertheless the series of enzymes have strong capability. The different straw degradation strains have strong interaction to each other. The combined degradation ability of cellulose-decomposing microorganisms and lignin funguses is higher than that of single strain. So the degradation effect of mixed microorganisms is better in the practical processing.The biogas is the product from the organic matter fermented by the anaerobic digestion. Raw material was mainly the human and animal's excrement, the crops straw stalk, the industry and agriculture and the cities life organic waste. The development biogas has the good efficiency in energy, the society and the economy. There are over 100 countries developing the biogas. This paper selected strains from existing degrading lignocelluloses microorganism for insure that those microorganism whether can culture with each other. The influences of the different mixtures of five strains that can degrade lignocelluloses were studied using mixture design. Regression model on microorganism composition and degrading rate of lignocelluloses and content of reducing sugar was established.Last apply the processed straw to ferment biogas that verify the effect of compound microbial. Through the studies we get the conclusion as follows:1. We selected 6 strains from 11 existing degrading lignocelluloses microorganism through plate culture and enzymes activity. They are Bacillus Subtilis, Bacillus Licheniformis, Trichoderma koningii, Canadian krusei, Trametes versicolor and Phaerochaete chrysosporium.2. We insure that 5 strains contain Bacillus Subtilis, Bacillus Licheniformis, Canadian krusei, Trametes versicolor and Phaerochaete chrysosporium can culture with each other.3. Apply mixture design to 5 strains fermentation at 30℃, the 10-day fermentation of straw, through determination of lignin and cellulose degradation rates and based on these response values satisfied all expectation were optimized, and the most excellent combinations of Bacillus Subtilis, Bacillus Licheniformis, Canadian krusei, Trametes versicolor, Phaerochaete chrysosporium were 12.1%,10%, 27.2%, 10.6%, and 40%, respectively. Then the degradation rates of cellulose and lignin are 35.47% and 26.41%.4. Applies the compound microbial inoculants to biogas made by rapeseed straw found that the gas yield increase and gas production cycle reduce. Cumulative gas production increase 17.8%.Porcessed seasome and peanuts'straw, the gas yield increase 25.4% and 17.6%.