Study On Microorganism Degradation Of Corn Straw To Produce Single Cell Protein

Biological degradation of corn straw to produce Single Cell Protein wasstudied in this paper. The purpose of the research is to broaden feedstuff source and raiseits quality by biologically transforming and utilizing recycled resources. The ultimateobjects of this work are to solve the problem of shortage of grain and environmentalpollution based on ecological balance and to promote agriculture developmentcontinuously as a kind of clean industry. Method of pretreatment, cellulase fermentationconditions and selection of strain to produce Single Cell Protein are discussed. Method ofco-fermentation on the production of Single Cell Protein is studied. Technical process toproduce Single Cell Protein by biologically degradation of corn straw is proposed. Themain conclusions are following points: Effect of pretreatment methods including milling process, dilute acid process, dilutealkaline process and ammonia process on the physical and chemical characteristics of cornstraw were studied. The reduction of crystallization degree and degradation ofhemicellulose and ligin were studied. The results showed ammonia process fits corn strawpretreatment. It was in 15% concentration and 72 hours. Its transforming percent was57.63%. The factors including media,water content,nitrogen sources, cultural temperature andcultural time were studied for producing cellulase by the mutant stain of Trichodermauirde. The results showed that the optium condition of solid fermentation was corn straw10g,wheat bran 5g, water 30ml, (NH4)2SO40.2g,at 30℃ for 84h. Under thiscondition, the enzyme activities towards CMC,FPA reached 372IU/g and 69IU/g. Geotrichum candidum Link,Candida utilis,Candida tropicalis and Saccharomycescerevisiae were studied. After culturing on the shaker, the number of live cell,cell dryweight,gross protein concentration were respectively determined. The strain with higherprotein concentration grows faster is used to produce SCP. The result indicated thatCandida utilis grew the fastest, and its gross protein concentration and biomassconcentration were the highest. It is the best stain to produce SCP. The optimum conditions of simultaneous solid-state fermentation were investigatedby using orthogonal test. We got 7.40% gross protein form corn straw(dry) in the condition6 Study on Microorganism Degradation of Corn Straw to Produce Single Cell Proteinof 46IU/g(FPA)cellulase substrate,1:2～1:3 water,10% Candida utilis 30℃ fermentation48 hours.