Screening Of Low-temperature,cellulose-degrading Bacteria And Their Effect On Cattle Manure Composting

Aerobic composting is one of the effective ways to realize the resource utilization of livestock and poultry manure.Low ambient winter temperatures in the northeast of China,It is difficult for the pile to warm up quickly with aerobic fermentation,and the compost product cannot meet the requirements,so in order to effectively solve the problem that the pile cannot start warming up quickly in low temperature environment.In this study,low temperature strains and cellulose degrading strains were screened from tundra and cow dung,optimization of enzyme production conditions resulted in the preparation of low-temperature composite bacterial agent and cellulose degrading composite bacterial agent,Inoculated into cow manure for low temperature composting,and compare with natural fermented cow manure,to study the effect of compound bacterial agents on the fermentation of cattle manure compost under low temperature environment.1.Three strains of cold-tolerant bacteria and five strains of cellulose-degrading bacteria were screened by temperature suitability assay and Congo red staining method,identification by 16S rDNA sequencing,the three cold-tolerant bacterial strains(D-3,D-7,D-16)were Pseudomonas frederiksbergensis 、 Acinetobacter calcoaceticus 、Pseudomonas synxantha;The five cellulose degrading bacteria strains(X-1,X-5,X-9,X-11,X-18)were Bacillus cereus、Bacillus subtilis、Bacillus amyloliquefaciens、Bacillus pumilus、Bacillus safensis。2.The antagonism test of the strain revealed that not antagonism between 3 strains of cold-tolerant bacteria,X-5 is antagonistic to four other bacterial strains,so remove X-5,the remaining strains were used to construct low-temperature complexes with cellulose degrading complexes.Optimization of four cellulose-degrading bacterial strains with different carbon sources,nitrogen sources,temperature and pH using a single-factor method,the optimum carbon sources for X-1,X-9,X-11,and X-18 are glucose,starch,dextrose,and sucrose,respectively;The optimum nitrogen sources were yeast powder,peptone,yeast powder,and yeast flour,respectively;Optimum enzyme-producing fermentation temperatures of 35 ℃,30 ℃,35 ℃ and 30 ℃,respectively;Optimum pH values of 8.0,6.0,8.0 and 8.0,respectively;The cellulase activity increased to 20.89 U/m L,23.45 U/m L,23.93 U/m L and 24.53 U/m L,respectively.3.The optimized obtained low-temperature composite bacterial agent and cellulose degrading composite bacterial agent were applied to cattle manure,divided into experimental group(low temperature compound bacterial agent + cellulose degrading compound bacterial agent),control group(natural fermentation).Conducting lowtemperature composting fermentation tests,determination of temperature,water content,pH,organic carbon,total nitrogen,C/N,seed germination index and other physicochemical properties of compost samples in different periods,The results showed that the experimental group entered the high temperature period at the 12 th d,The high temperature period was maintained for 10 d,The control group did not enter the high temperature period,the test group was highly significantly higher than the control group(P<0.01);The water content of the test group decreased by 31.65%,the water content of the control group decreased by 19.41%,the test group was highly significantly higher than the control group(P<0.01);The pH values of the test group varied widely,the final pH value is 7.61,no significant change in pH in the control group,with a final pH of 7.42;The organic carbon content of the test group finally reached 28.5%,the organic carbon content of the control group eventually reached38.5%,the test group was highly significantly higher than the control group(P<0.01);The final total nitrogen content of the test group reached 1.98%,The control group ended up with 1.69% of total nitrogen,the test group was highly significantly higher than the control group(P<0.01);The C/N of the test group finally reached 14.61,the control group C/N ended up at 22.78,the test group was highly significantly higher than the control group(P<0.01);The final seed germination index of the test group was91.5%,the final seed germination index of the control group was 42.6%,the test group was highly significantly higher than the control group(P<0.01).From the above study it is concluded that the addition of low temperature compound bacterial agent and cellulose compound bacterial agent in cow manure can start warming up quickly below 0℃,maintain high temperature period for a longer period,accelerate the composting process,reach the composting decomposition standards.