Efficient Cellulose Strain Selection And Construction Of Flora

In order to improve the degradation efficiency of straw,the coordinate combination of microorganisim which increased the bacterial diversity accompanied with the research of screening out the cellulose degradation bacterial and their flora degradation effect are all developed 。 Based on the optimal composition,the most efficient degradation of blended bacterial to cellulose was obtained to resolve weather they are adequated used。This experiment uses the screening method of Congo red transparent circle, screening from the rot of cotton stalk, sheep rumen liquor, forestry wood sample. Preliminary screening out 10 strains which able to degrade cellulose strains.Then the test of CMC enzyme activity with better degradation strains by 3, 5-2 nitro salicylic acid colorimetric on sugar method(DNS) strains, getting the efficient cellulolytic strains N05, N13 and N21, to build composite flora; By optimizing the culture conditions of bacteria to maximize the microbes degradation ability; By weight-loss method and scanning electron microscope study bacteria degradation ability; F inally, research the N05, N13 and N21’s morphology and molecular identif ication of them.Through the above experiment getting the results as follows:(1) Cellulose Congo red medium on the collection of samples are used to screen the result based on transparent circle diameter/diameter ratio of colony(D/d), and getting 10 bacterial strains more capable to break down the cellulose. Then inoculat the bacterial strains to the Enzyme production liquid culture medium to resieve enzyme activity by testing the CMC, eventually selected 3 high efficiency strains N05, N13, N21 of cellulose degradation strains. These three strains are combined to find out a best combination which turn out to be SDP(N05 + N13 + N21) by enzyme assay comparison.(2) In the condition of liquid enzyme production cultivation, the temperature, time, initial p H and nitrogen source effects on flora SDP on cellulose enzyme activity were researched. Results showed that optimization straw degradation of bacteria fermentation conditions is 14(A3, B1 C5, D3), temperature 30 ℃, time period of 5 d, nitrogen source for NH4NO3, initial pH values of 6.0.(3) The SDP flora of maize straw degradation ability is stronger, before being degraded containing 36.58% cellulose, hemicellulose by 25.60%、and lignin 16.35%. By the end of the 8 d cultivating cellulose was reduced by 25.37%, hemicellulose was reduced by 27.32%, lignin was reduced by 15.29%. By comparing the maize straw before and afterl scanning figure of the microbia degradation under electron microscopy, through microbial degradation, the structure of lignocellulose is destroyed, become loose, low crystallinity. Degradation of mixed corn straw effect is better than single one.(4) As to observation of strain N05, N13 and N21 morphological and 16 s r DNA and 18 s r DNA sequencing and sequence analysis, N05, N13 and N21 fungus were indentified as Aspergillus(Aspergillus tubingensis), huge Bacillus(Bacillus megaterium) and Bacillus subtilis( Bacillus sp.LX-102) respectively.In the domestic and foreign existing research report, cellulose degrading bacteria mainly concentrated in the fiber(Cellu- lomonas), bacterium Pseudomonas(Pseudomonas), Clostridium(Clostridium) and Bacillus(Bacillus), and about the study on the degradation of cellulose by tower bin aspergillus, and almost did not see report.Mixed bacteria cellulose degradation effect is higher than that of single strain, this test for microbial mixed culture degradation of cellulose provides a theoretical basis.