Characterization And Identification Of Lactic Acid Bacteria Isolated From Kobresia Littledalei In Tibet

Silage is one of the effective measures to solve problem of seasonal forage supply imbalance in Tibet region. Because of the extreme environment in Tibet, there is little suitable commercialization lactic acid bacteria silage additives can be used in the area to produce good quality silage. Therefore, to seek and explore native LAB germplasm resources for the production of silage in the region may be a feasible approach to solve the problem.In this study, the raw materials is the Kobresia littledalei that distribute in a wide range of area especially in northern Tibetan alpine areas,which also has high forage feeding value. So to separate, identify, and research biological characteristics of lactic acid bacteria adhere on materials, will provide a scientific basis to find out good lactic acid bacteria germplasm resources for producing silage forage. Total of19lactic acid bacterias isolate from the Kobresia littledalei from different sites,which also were identified by16S rRNA gene sequences analysis and phylogenetic tree based on16SrRNA sequence analyses were also performed respectively. The results showed that6isolates could be Weissella confuse,11isolates are Weissella. Cibaria and2isolates belongs to Leuconostoc mesenteroides subsp.In the further experiment of the physiological and biochemical characteristics research, both Weissella and Leuconostoc show a stronger tolerance to adapt the regional harsh environment. Most of the isolates can grow in4℃-40℃temperature conditions, some strains, such as the Glcan also grow in temperature of50℃, while optimum growth temperature of Weissella and Leuconostoc is30℃-40℃. In the acid test the bacteria is also exhibit similar characteristics, most of the strains can survive in the range of pH9.5and pH3.5, Some strains even can grow under pH3and pH9.5conditions. About capacity of using the carbon sources, Weissella and Leuconostoc are also shows special characteristics Weissella can ferment arabinose, do not ferment galactose, xylose, esculin and Weissella. Cibaria do not ferment arabinose, melibiose, mannitol, and amygdalin. However, the vast majority of the lactic acid bacteria in the study can take advantage of these carbon sources, Leuconostoc can use carbon sources in large carbon range which also significantly stronger than the same species in other environments isolated from plants.By testing growth rate of lactic acid bacteria and speed of the pH, the experiment found good lactic acid bacterias. N1(Weissella cibarid) and N6(Leuconostoc mesentlroides subsp.mesenteroides)in Naqu; G1(Weissella confuse) and G4(Leuconostoc mesenteroides subsp. Mesenteroides) in Gulu; D4(Weissella confuse) in Deqing.\...