The Effects Of Corn Straw Hydrolysis Saccharification By Bacteria Mixture

Energy,resources and environment problems have become the major obstacle to the sustainable socioeconomic development.It has become the world's urgent task about the development of new alternative energy and sustainable resource.Using lignocellulose to produce fuel alcohol for its clean,security and other advantages is become people study's hot spots.It included the saccharification process and the ethanol fermentation process by us ing lignocellulose to produce fuel ethanol,in which the pretreatment of lignocellulosic saccharification process is the most important part of the fuel ethanol production pro-cess.Firstly the effects of four different pretreatment methods on the degradation and saccharification of corn stalks were studied in this study.The four pretreatment meth-ods were as follows:extrusion method combined with Trichoderma viride pretreatment method,sulfuric acid combined with Trichoderma viride pretreatment method,Variega ted Coriolus versicolor/Pleurotus ostreatus combined with Trichoderma viride pretre-atment method and only Trichoderma viride pretreatment method.Based on the analys-is of the results of corn straw pretreatment,Separated raw sugar yield is given priorit y to,the suitable maize straw pretreatment method is determined.Secondly,the effects of mixed ratio of different volume of Variegated Coriolus versicolor and Pleurotus o-streatus on the degradation of maize straw were studied.At the same time,the chang e of enzyme activity with time was found in the best mixing ratio of Coriolus versic-olor/Pleurotus ostreatus.Finally,used decomposition temperature,adding amount of mixed bacteria,initial pH value and particle size of corn st-raw as experimental factor s,the degradation rate,cellulose degradation rate,hemicellulose degradation rate and lignin degradation rate of maize straw were studied under different process conditions.The main conclusions of this paper were as follows:(1)The Variegated Coriolus versicolor/Pleurotus ostreatus combined with Trichoderma viride pretreatment method,the yield of reducing sugar in the process of degrading corn stalks was best than that of extrusion method combined with Trichoderma viride pretreatment method,sulfuric acid combined with Trichoderma viride pretreatment method and only Trichoderma viride pretreatment method.(2)The ratio of reducing sugar in the process of degrading corn stalks under mixed ratio of 1:1 by volume was slightly higher than that of other mixed ratio on Variegated Coriolus versicolor and Pleurotus ostreatus.(3)Under the mixed ratio of 1:1 on Variegated Coriolus versicolor and Pleurotus ostreatus,and culture time was ten days,the activity of Laccase(Lac)was the highest.The maximum of Lac was 215 U/L.With the same mixed ratio,when culture time was nineteen days,the activity of Lipase(Lip)was the highest.The maximum of Lip was2102 U/L.(4)By the orthogonal rotation test,it was clear that the yield of sugar was the best when the temperature was 28.9? the pH value was 5.3,the mixed bacteria content was 31.9mL/L and the straw diameter was 75 mesh.And the maximum of reduced sugar was 31.8 percents.This study not only provided an effective way to recycle the residues in the production of Pleurotus ostreatus,but also could support some reference for the corn hydrolysis of ethanol by straw corn straw hydrolysis and saccharification to product fuel ethanol.