Isolation,Identification And Degradation Characteristics Of Cellulose Degrading Bacteria From Sika Deer(Cervus Nippon) Rumen

In order to explore the cellulose degrading bacteria in the rumen of sika deer,CMC-Na medium was used to obtain fourteen bacterial strains from Sika Deer rumen.Congo red staining method was used to screened strains for cellulase production,cellulases activity were futher determined.The two strains with the highest cellulose degrading ability were screened finally.The enzymatic properties of two strains were studied.The changes of NDF and ADF were determined about soybean meal,wheat bran and corn stover fermentation to study the degradation.The aim of this study is to screen out the effective cellulose degrading bacteria strains to improve feed utilization and treat agricultural waste.Strains capable of discoloring the carboxymethyl cellulose-congo red medium to produce transparent circles from Sika Deer rumen was screened out.The strain was isolated and purified,cellulases activity were determined using the DNS method to rescreening.Cellulose degrading bacteria N-11 and Bs was screen out according to transparent circles and cellulases activity.Combined with morphological observation,physiological properties and molecular biological analysis of strains N-11 and Bs,N-11 was identified as Bacillus cereus,Bs was identified as Bacillus subtilis.Study on enzyme production conditions and enzymatic properties of strains N-11 and Bs,The results show that when their pH was 6.0⁷.0,and their fermentation temperature was 40?,they had the highest enzyme activity.N-11 took 36h to reach the peak of FPA and CMCA production,FPA and CMCA reached to12.413,12.563 U/mL,?-glucosidase reached to 10.08 U/mL at 48 h.Bs took 48h to reach the peak of cellulase production,CMCA of Bs reached to 18.378 U/mL,FPA to 14.563 U/mL and?-glucosidase reached to 16.267 U/mL.The enzyme activity of N-11 were the highest when inoculum concentration was 5%,The enzyme activity of Bs reached the maximum when the inoculation amount was 2%.When pH was 6.0⁷.0,temperature was20⁵0?,the crude enzyme solution has a high stability,enzyme activity remains above 80%.The addition of Na⁺,K⁺and Mg²⁺in the medium can promote cellulase production of N-11 and Bs;Zn²⁺,Fe³⁺and Cu²⁺play an inhibitory role;Ca²⁺and Mn²⁺have no obvious effect;Co²⁺has a promoting effect on N-11,Co²⁺can cause the inhibition of Bs,but no obvious inhibition was observed.The change of the content of NDF,ADF in the feed is used as an important indicator to test whether the cellulose degrading bacteria play a role in the fermentation process.Feeds containing no strain were used as the control group and feed with strain was used as the experimental group.Changes of pH,dry matter,and NDF,ADF in the feed were measured and analyzed.The results showed that pH and dry matter had no significant change in the fermentation process and the content of NDF,ADF was reduced significantly.N-11 and Bs promote the fermentation of corn stover powder.Compared with strain B_S,N-11 have a tendency to degrade cellulose in the course of soybean meal fermentation.During the fermentation of wheat bran,N-11,Bs had no obvious effect on the degradation of NDF,ADF.N-11,Bs promoted the degradation of NDF,ADF significantly in the process of corn straw powder fermentation.In the experiment group of N-11,the NDF and ADF of the experimental group were reduced by 9.56%and 5.04%respectively than those in the control group,and the content of NDF and ADF in the experimental group decreased by 21.5%and 7.09%respectively than those in the control group.