Analysis Of Microflora Of Differentoat Mixed Broadcast Grassland In Sanjiangyuan Experimental Area And Screening And Utilization Of Low Temperature Lactic Acid Bacteria

In this study,oat(Avena sativa L.)+ common vetches(Vicia sativa L.),oat+ common vetches + Heisimai(Secale cereal L.),oat+ broad bean(Vicia faba L.)and oatunicast 4 kinds of oatmeal in the Sanjiangyuan experimental area we planted forage was used as main material.To explored the foliar microflora of four research materials,analyzed the difference of microbial community and quantity in different oat combination leaves,and screen for excellent silage low-temperature lactic acid bacteria from it as Silage additive.Used to evaluate the silage effect of Low temperature lactic acid bacteria in four localoatcombinations.In order to provide a scientific basis for the development and utilization of forage microorganisms in the Sanjiangyuan test area,determine the silage method suitable for low temperature areas.The results are as follows:High-throughput sequencing of the bacterial genome in the material was carried out by using metagenomic sequencing.The results showed that there were differences in the number of unique bacterial communities in the leaves of different oat combination.The number of unique bacterial communities was the biggest in oat+ common vetch combination.The species richness of the four oat combination species was different,and the oat + broad bean combination species diversity was the highest.The dominant bacteria in the four oat combination foliar bacteria in the Sanjiangyuan test area are Enterobacteriaceae,Pantoea,Pseudomonadaceae and Erwinia.Twelve strains of lactic acid bacteria were isolated by the dilution coating method.After low temperature culture,acid production capacity,growth rate and physiological and biochemical characteristics were determined and screened,and finally three excellent silage lactic acid bacteria GN3,GN11 and GN12 were obtained.Among them,GN3 strain has the best characteristics.Using 16 S rDNA molecular identification technology,it was determined that three excellent silage lactic acid bacteria were Enterococcus faecium.Application second-generation sequencing technology to carry out the whole genome sequencing of E.faecium GN3.The total gene length of E.faecium GN3 strain was 5005143 bp,and 18 scaffolds were assembled.Functional gene annotation abtained the genes related to biosynthesis,energy metabolism,environmental adaptation,and carbohydrate metabolism of metabolism and secondary metabolites.The evaluation results of silage effect of different inoculums of lactic acid bacteria to 4 oat combinations with showed that: Compared with the CK control group,the Enterococcus faecium as a lactic acid bacteria additive can significantly improve the Silage forage quality of four oat combinations in the Sanjiangyuan test area.Application the in vitro gas production test to evaluated the digestibility of forage silage dry matter.The results show that when the inoculation amount of low-temperature lactic acid bacteria was 3%,the silage dry matter digestibility of oat+ common vetches + Heisimai combination was the highest,and the silage nutrition quality of this treatment group was the best.In another words,this oat combination has the highest content of DM and CP,and the content of ADF and NDF is low,the quality of silage is the best.That is,the pH and AN/TN ratio are the lowest.