The Screening And Identification Of Cellulase Bacterial Strain From Intestines Of Hermetia Illucens L. Maggots

The coarse fiber of swine manure and shard was significantly low after digesting by Hermetia illucens L. maggots and during the process microbe in intestines of maggots may play an important role. Considering the environmental protection and utilization new strains, it was necessary to screen and identify strains with enzyme activity of cellulose. Seven strains with the activity of cellulose had been screened and identified from the 4th larvae when they had the best digestion to swine manure. Through the determination of CMCase activity and FPA activity, obtain a strain named X4 with high cellulose activity. Extract the crude fiber from swine manure and residue that had been digested by Hermetia illucens L. maggots and degrade with X4. Design orthogonal test to optimize the conditions of fermentation. The results were as follow.Seven strains had been screened. There were named X1, X2, X3, X4, X5, X6 and X7. Determine the seven strains by the methods of morphological characteristics and 16s rDNA. The antibiotic spectra of the seven showed X4 could inhibit Escherichia coli and Sclerotinia sclerotiorum, X5 could inhibit Staphylococcus aureus and Sclerotinia sclerotiorum, X6 and X7 could inhibit Sclerotinia sclerotiorum. Determine enzyme activity of the seven strains with the methods of DNS and FPA. X4 had the highest enzyme activity (7 IU).Determine the X4-growth curve with beef cream-peptone culture medium. The result showed that the logarithmic growth phase of X4 was 5-7h. Culture them for 48h and calculate the degradation rate. The results were that the degradation rate of swine manure was 12.64% and the degradation rate of residue was 10%.Make the fermentation medium with corn and soybean. The optimal condition of producing cellulose was studied by three factors and three levels orthogonal experiment and the results were the best initial pH 9.0, incubating temperature 45℃and incubating time 36h. The enzyme activity was 117.131U and increased nearly 17 times than before. Introduced reliable technical parameters are suitable for commercial production...