Screening Of Lactic Acid Bacterial Community At Low Temperature And Its Application In Mixed Fermentation Fodder With Cornstalks And Potato Residues

With the rapid development of animal husbandry in our country,people and livestock for food has been increasingly serious.Cornstalk’s Waste pollution of the environment problem increasingly prominent,The cornstalk keep in storage after harvest as a feed can solve the pollution problem.In addition,the potato industry of Heilongjiang Province has developed rapidly,the by-products from potato has become one of the bottleneck of industrial development.Cornstalks and potato residues mixed fermentation to develop raw feed is a important way to solve the problem of feed shortage and realize the efficient utilization of biomass resources.This study aimed at the northeast autumn after straw and potato harvest,the environment temperature is low,the test on the basis of the natural bacteria in silage,through continuous restrictive training method,under the condition of 10℃ stationary training,with pH value as the index,to get a composite microbial system used for fermenting mixing stalks of corn and potato residue to produce feeds at low temperature,using high-through sequencing technologies to the low-temperature composite microbial system in the species composition diversity analysis;With sensory evaluation,pH value,dry matter,ADF and NDF as evaluation indexes of mixed fermentation fodder.Determine the best raw material ratio and the best nitrogen source choice.In moisture,temperature and inoculated quantity of single factor are studied on the mixed fermentation system pH value and the influence of dry matter.Determine the best fermentation parameter.Using high-throughput sequencing method analyzed the mixed feed fermentation’s beginning and the end microbial community composition.The specific test results were as follows:1.By the method of limited cultivation method and stable cultivating get a composite microbial system.The results of high-throughput sequencing showed that mainly microbial in the genus classification levels was lactobacillus、Candidatus Solibacter、Acidothermus、Bacillus,in the species classification levels was Lactobacillus paracasei 、 Enterococcus faecium 、Alcanivorax dieselolei.And Lactic acid bacteria accounted for 72.8%.The feed quality of mixed fermentation with corn stalk and potato residues can be improved by inoculation of the bacteria community.2.Through without raw material proportion optimization and the best nitrogen source selection,according to the corn stalk and potato residue blending ratio is 3:1,can significantlyincrease the content of crude protein and reduce the ADF and NDF.Selection of urea and corn flour as a nitrogen source,can not only meet the requirements of fermentation required also more practical economy.3.The study of single factor method was used to study the different moisture,temperature and quantity of the effect of pH and dry matter of fermentation system,Get the best fermentation parameter is moisture content 70%,temperature is 10℃,1% inoculated.4.Through analyzing microbial diversity in the fermentation system,the initial phase in the fermentation,harmful microbes sort is more,the Yersinia,Leuconostoc,Enterococcus the amount of the most,in the late fermentation,contrast of harmful microorganism is relatively more,and inoculation of low-temperature lactic acid bacteria harmful microbes was few,Lactobacillus accounted for 92.5%,therefore the lactic acid bacteria can grow in the colonization in the fermentation system at low temperature,inhibit harmful miscellaneous bacterium,produce lactic acid in order to improve the feed quality.