Screening,identification And Application Of High Quality Lactic Acid Bacteria In Silages In Kunming

In order to screen out lactic acid bacteria suitable for silage in Kunming area and promote the development of grass husbandry in Yunnan province,three kinds of whole corn(Zea mays),alfalfa(Medicago sativa)and Dactylis glomerata silage fermented for 60 days were selected as test materials.The research on the screening and identification of high-quality lactic acid bacteria in the silage in Kunming area was carried out,through which the high-quality lactic acid bacteria strains suitable for the climatic conditions in Kunming were screened out,and the selected strains were further processed into bacterial liquid,and different types of lactic acid bacteria were filled into the whole corn and alfalfa silage alone or in a 1:1 ratio.And whole corn and alfalfa(fresh weight ratio =3:1)mixed silage to test the effect of improving the fermentation quality of silage.The research conclusions are as follows:1.A total of 83 strains of Lactobacillus were isolated from 3 kinds of high quality silage.Physiological and biochemical characteristics and 16 r RNA amplification sequencing showed that Lactobacillus plantarum was the most common lactobacillus in silage in Kunming area,accounting for 50.6%;This was followed by pediococcus pentosus and Lactobacillus brevis with 21.7% each.According to the growth activity and acid-producing ability of lactic acid bacteria,three strains of high quality lactic acid bacteria B10,B16 and C23 were further screened,which were Lactobacillus brevis,Lactobacillus plantarum and laminococcus pentosus,respectively.The order of acid production rate and growth rate was B16 > C23 > B10.2.Compared with natural fermentation,Lactobacillus plantarum B16 and Tablets pentosus C23 added alone or 1:1 with Lactobacillus brevis B10 could significantly increase the number of Lactobacillus in whole corn silage(P < 0.05).The addition of B10 alone or 1:1 combined with B16 and C23 significantly increased the acetic acid content and aerobic stability of whole corn silage,and decreased the NH3-N content and the number of aerobic bacteria(P < 0.05).And commercial complex lactic acid bacteria(Lactobacillus plantarum: Lactobacillus brucei=1: 9)Compared with the addition of high quality local lactobacillus single or complex bacteria solution,DM and CP contents of whole corn silage could be better preserved.However,due to the lower proportion of Lactobacillus brevis in high quality local lactobacillus complex bacteria solution,the improvement effect of high quality local lactobacillus complex bacteria on the aerobic stability of whole corn silage was not as good as that of commercial complex lactobacillus.3.Compared with natural fermentation,the addition of high quality local lactic acid bacteria can significantly increase the number of lactic acid bacteria in alfalfa silage samples,reduce the number of aerobic bacteria and mold,increase the contents of lactic acid and acetic acid in silage samples(P < 0.05),inhibit the decomposition of protein and amino acid in feed materials by harmful bacteria,and effectively preserve the nutrients in the silage.Compared with sucrose molasses,the addition of high quality local lactic acid bacteria had a lower effect on the quality improvement of alfalfa silage than molasses,indicating that molasses was more suitable for the preparation of alfalfa silage than lactic acid bacteria.4.Compared with natural fermentation,the silage quality of corn + alfalfa mixed samples was significantly improved by adding local high quality lactic acid bacteria.The p H value and NH3-N content of mixed silage samples reached the standard of high quality silage.The content of lactic acid in silage prepared with local premium pentococcus C23 was significantly higher than that in other treatments(P<0.05).The protein content of silage supplemented with local high quality Lactobacillus plantarum B16 was significantly higher than that of other treatments(P<0.05).Compared with commercial complex lactic acid bacteria(Lactobacillus plantarum:Lactobacillus brucei = 1:9),the addition effect of single or complex liquid of high-quality local lactic acid bacteria was better overall.5.The comprehensive evaluation results of fuzzy mathematical membership function showed that high quality native lactic acid bacteria could play a better effect on whole corn and corn + alfalfa mixed silage,but its effect on alfalfa alone silage was not as good as molasses.For whole corn silage,Lactobacillus plantarum B16 and Lactobacillus brevis is the best addition,but it is recommended to use Lactobacillus brevis B10 as the main and Lactobacillus plantarum B16 as a supplement,in order to better play its effect of improving aerobic stability.For corn and alfalfa mixed silage,adding high-quality local pentococcus C23 or Lactobacillus brevis B10 alone has the best effect,which is recommended as the most suitable bacteria for corn and alfalfa mixed silage.In conclusion,Lactobacillus brevity B10,Lactobacillus plantarum B16 and Lamella pentose C23 screened in this study are high-quality local lactobacillus strains suitable for silage mixing in Kunming area.The application effect of lactobacillus brevity on whole corn and corn + alfalfa mixed silage is better than that of commercial lactobacillus preparations.The results of this study can provide theoretical support for the research and development of high quality local lactic acid bacteria preparation for silage in Kunming area.