The Biological Characteristics Of Lactic Acid Bacteria Isolated From Kobresia Littledalei And Its Effects On The Fermentation Quality Of Alfalfa

In the present study, it was investigated that physiological and biochemical characteristics of epiphytic lactic acid bacteria from Kobresia littledalei. Leuconostoc mesenteroides subsp. Strains, Weissella confusa strains and Weissella cibaria strains were isolated from Kobresia littledalei. After the investigation of the growth at different temperature and pH conditions, salt tolerance, and sugar fermentation patterns on these isolated strains, and then measured the acid production rate and the growth ability of these strains. Using these3strains and their comparisons as additives, the alfalfa silage as raw material for silage fermentation, after storing for60days at the room temperature, we analyzed these samples. Identifying through the senses and laboratory determination, we did a comparative study to see the improvement effect of the silage fermentation of these3strains and the standard strain of alfalfa. Results show that:1) Compared with the same strain isolated from conventional conditions, these lactic acid bacteria isolated from Kobresia littledalei have better temperature and salt tolerance, and they could also more widely fermentation sugars.After fermenting at the temperature of37°C for24h in MRS liquid medium, it examined the acid production rate and growth capacity of these3strains, the results indicate that Leuconostoc mesenteroides subsp. Strains, Weissella confusa strains and Weissella cibaria strains did all have strong growth and acid production capacity, and the most of which is the Leuconostoc mesenteroides subsp.2)In laboratory conditions, in bags evacuated way, the quality of the fermentation alfalfa was as follows:Compared with the blank control group, adding the two Weissella cibaria and two Weissella confusa could not significantly lower the pH and AN/TN values, and not they promote the production of lactic acid, so they could not effectively improve silage quality. Adding Leuconostoc mesenteroides subsp. Strains could significantly reduce the pH and AN/TN, promote the production of lactic acid, and improve the fermentation quality of alfalfa. While the effect of L.mesentlroides Subsp.mesenteroides control strain on silage quality is not obvious.