Exploitation And Utilization Of Corn Stalks Silage Agents In The Eastern Part Of Inner Mongolia Autonomous Region

With the increasing of the material and the energy needs of human beings and the increasing pollution to the environment,how to use straw resources scientifically and rationally has become a major problem that plagues national governments.The Inner Mongolia Autonomous Region is a major province for corn cultivation and can produce about 10% of the China's corn production.Corn stalks is rich in cellulose,which is the world's most abundant renewable resource,has attracted the attention of a large number of scholars.Therefore,this study selects corn straw as raw material according to local conditions,selected strains that can efficiently degrade corn straw,and lays a foundation for the utilization of corn straw.In order to make the screened strains suitable for the low-temperature climate in eastern Inner Mongolia,this study isolated and purified the strains from the samples collected from the city of Tongliao and Chifeng,identified the enzyme activity,and determined the ability to degrade corn stalks and the sugar produce ability.For strains with high sugar production capacity and strains of yeast and lactic acid bacteria to make the agents,and test their effects on corn stalks.The results of this study are as follows:(1)130 strains of cellulose-degrading bacteria were screened out from 13 samples taken from the eastern part of the Inner Mongolia Autonomous Region.Among them,52 strains had carboxymethylcellulose enzyme activity(CMCase)and there are 16 strains had high CMCase activity.The best comprehensive ability of strain Bacillus methylotrophicus 2-4 was obtained through antagonistic experiment,straw degradation experiment and sugar production experiment,which is the ideal strain source of corn straw micro-storage.(2)Lactic acid bacteria plays a very important role in the process of straw microstorage because of their ability to improve feed palatability.In this study,Lactobacillus plantarum S1 was preserved in a low temperature in our lab and it has a high-quality of making silage.Since the simultaneous use of 2-4 and S1 may not achieve the best effect,2-4 and S1 are made into different bacterial agents respectively,and the difference in time between release to the fermentation system avoids strains of mutual influence.(3)Optimize the conditions of freeze-drying Bacillus methylotrophicus 2-4 through response surface experiments.The results showed that the centrifugal conditions were: when the centrifugation time was 10 min,the temperature was 3.7 °C,and the rotation speed was 5200 r/min,the yield was 89.21%.Screened from five kinds of lyoprotectants: when the concentration of skim milk was 10%,peptone concentration was 10.2%,and glucose concentration was 5.2%,the yield of bacteria was 88.33%.(4)Lactobacillus plantarum S1 was immobilized by an embedding method.The results showed that the best spheronization effect was achieved when 6% polyvinyl alcohol(PVA)+ 0.4% sodium alginate(SA)+ 0.3% carboxymethylcellulose sodium(CMC-Na)was used for embedding-crosslinking.When using 1.2%SA+0.5%CMCNa for direct embedding,the balling effect is best.By comparing five kinds of immobilization techniques,1.2% SA+0.5% CMC-Na and adsorbed corn flour were combined to form an immobilized carrier mixture.The mixture was dropped into 4% calcium chloride and embedded directly for 24 hours to obtain a small immobilization balls,the mechanical strength and embedding rate are superior to other processes.(5)After the lyophilized powder is rehydrated at 37°C,it is placed in a fermentation bag with the immobilized pellets,the bag containing corn stalks which have already cut into 1-3cm long.We optimized the moisture content,inoculation amount,fermentation time,and the inoculum proportion of two kinds of microbial agents.The crude fiber(CF)degradation rate and crude protein(CP)increase rate of corn stover were used as indicators.The results showed that: CP increased by 14.002%,CF degraded by 14.887%,and the quality of the silage was effectively improved.Traditional microbiological immobilization methods are often used to treat liquid sewage.The mechanical strength of the carrier must be very high to ensure the integrity of the ball.This study innovatively uses the characteristics of sustained release of immobilized pellets,and aims to release the strain by breaking the carrier.The lyophilized strain 2-4 can pretreat the corn stover,destroy the structure of the cellulose,and produce sufficient soluble monosaccharides for use by the S1.At the same time,2-4 can also degrade the immobilized bead,which is mainly composed of CMC-Na,and accelerates the release of S1 into the micro-reservoir system.The strains we selected in this study were all screened locally in the eastern part of the Inner Mongolia Autonomous Region.This ensures that the agent can be well adapted to the local environment.In the small-scale experiment,the bacterial agents used had better processing capability for corn stalks and had higher potential for application.This study provides a theoretical basis for the utilization of corn stalks in the eastern part of the Inner Mongolia Autonomous Region.