Physical Pretreatment Of Straw And Study Of Fermentation Technology With Bacteria Flora

This paper is mainly study at different physical pretreatment of straw, and fermentation technology with two pairs of bacterial flora 5 and 6 ,which can filtered out of the cellulolytic strong and stable.And structure of straw by physical and physical-biologic treatment was observed by SEM.In this study, four physical pretreatment methods can be used. These treatment are ultrasonic wave treatment ,frozen treatment,high temperature and pressure treatment and Temperature heating treatment. Each method of different factors and conditions designed to determination cellulose, hemicelluloses and lignin, and the combination with electron microscopy observation of the structure of the straw, we can find four treatments have certain role for higher cellulose and lower lignin. The optimum conditions of ultrasonic wave treatment is 490W,30min.In that way, cellulose content is reach to 38.53%.For frozen treatment, cellulose content is reach to 38.46% and lignin is down to 12.09% when condition is 4oC,120h.Cellulose content is reach to 38.82% when condition is 0.15MPa,127oC,2h by high temperature and pressure treatment. A best pretreatment method is temperature heating. In that way, cellulose content is reach to 40.68% and lignin is down to 11.6%,which cellulose highest and lignin lowest.Bacterial fermentation of the straw optimize medium, ratio of carbon and nitrogen source, the ratio of dipotassium hydrogen phosphate and magnesium sulfate, calcium and trace elements as a single factor involved. The optimal combination of single factor into a new medium,the medium compared with the original , continuous measurement sugar content for 7 days.Reducing sugar reached to 7.83% in 6 days for No.5,by raise 7.1% than 7.31% using old mediun. Reducing sugar reached to 7.9% in 5 days for No.6,by raise 28% than 6.16% using old mediun.After determination treatments of reducing sugar and the optimized medium,and important factors though Plackett-Burman design,which the selected temperature,pH,run speed, liquid volume, straw particle size as factors,reducing sugar content as response. It find pH and temperature as the main factors,Then determine sugar by design 33 factorial experiment, using three different straw material by three better physical pretreatment, and changing in temperature and pH level. It find the size of affect is temperature>pH>material. Optimal conditions of fermentation production sugar for For bacterial flora No.6 is 37oC, pH=8.5,which produce reducing sugar 8.58% at average...