Screening Of Compound Bacteria Strains For Rape Straw Composting In Alpine Regions

Qinghai Province is a major province for rapeseed planting in my country,and rapeseed is the largest economic oil crop in Qinghai Province.Composting straw is one of the effective measures for crop resource utilization.Straw contains cellulose,which is more difficult to degrade during composting.When rape straw is composted,adding a cellulose-degrading bacterial agent to it and using microorganisms to degrade cellulose is one of the effective measures to solve this problem.In order to screen out strains suitable for cellulose degradation of rape straw in Qinghai,this paper screened out cellulose-degrading bacteria from different habitats in Qinghai Province.A compound bacterial strain suitable for rape straw composting in Qinghai area was obtained.The main experimental research results are as follows:(1)A total of 97 strains were isolated and purified by screening,including76 strains of bacterial,12 strains of fungi and 9 strains of actinomycetes.After the initial screening experiment of Congo red and the re-screening experiment of enzyme activity determination,6 strains with strong cellulose ability were screened out.(2)A single-strain compost test was established to determine the physical and chemical indicators of compost.Among them,the principal component analysis values of T1,T2,and T3 treatments were higher.The high temperature durations of T1,T2,and T3 piles were 29 days,25 days,and 17 days,respectively;the p H was within the standard range of the organic fertilizer industry 96%,144%;at the end of composting,the C/N of T1(17.15),T2(14.90),and T3(16.42)treatments were lower than those of the control group(20.02),indicating that the composting effect was better;thus,T1 and T2 were screened out.The strains K1,H36-7-4 and AH-5-1 in the T3 treatment were used for the construction of compound strains.(3)The antagonistic test showed that the three strains had no antagonistic effect.The weight loss rate of straw combined with ABC treatment showed the best performance of 35.07%;On the 30th day of the straw fermentation indoor test,the cellulose degradation rate was 34.66%,and the hemicellulose degradation rate was16.31%.(4)By adding compound bacterial agent ABC to the fermentation of pig manure and rape straw compost,compared with the control group CK,the temperature of the ABC treatment was 1 day longer than that of the CK treatment in the high temperature period,and it entered the cooling period 11 days earlier,and the maximum temperature of the compost was 1.4℃ higher than that of the control group;the p H and electrical conductivity(EC)values of ABC treatment were 8.04 and 1.32 m S/cm,respectively,which were 0.14 and 0.8 m S/cm lower than those of the control group;the seed germination index of the compound inoculant ABC treatment group reached the decomposing standard on the 16 th day of composting At the end of composting,the seed germination index of ABC treatment was 129.47%,while that of CK treatment was 88.53%;the organic matter degradation rate of ABC treatment was40.28%,and the contents of total nitrogen,total phosphorus and total potassium were2.06%,3.19%,1.63%,respectively at the end of composting,the cellulose degradation rate of the ABC treatment with the three strains was 14.45%,and the hemicellulose degradation rate was 39.28%.(5)Through morphology and molecular biology identification,K1 and H36-7-4 are Bacillus hatolerans;cellulose degrading bacteria AH-5-1 is Brevibacterium frigoritolerans.