Effect Of Selenomonas Ruminantium And Its Gene Transpositional Engineering Bacteria On Fermentation Of Sheep Rumen

Ten strains of the strictly anaerobic bacterium which were capable of producing propionic acid were isolated from ruminal fulid and the biochemical characteristics were analyzed for one strain of them, named strain K6.The 16S rRNA gene of K6 was amplified by polymerase chain reaction(PCR)and sequenced.The sequence obtained was 98% identical to it of Selenomonas ruminantium in GenBank.K6 was identified through morphology and biochemical characteristics and 16S rRNA gene sequence was confirmed as Selenomonas ruminantium.Twelve sheep were randomly allocated into two groups and each group was inoculated with 100 mL K6 and TnK6 via the rumen cannula,respectively.Ruminal fluid was sampled to analysis pH and VFA from 0h to 144h. The results showed as follows:The pH, the acetate concentration and the ratio of acetate to propionate(C2/C3) in TnK6 group were significantly lower than that of K6 group(p<0.05,p<0.01).The concentration of lactate,propionate and butyrate were no significant difference in two groups(p>0.05).It is considered that the lactic acid in rumen could be utilized by the K6 and TnK6 to produce acetic acid,propiontic acid and butyric acid and degrade the pH and the ratio of acetic acid to propionic. The study on the effect of K6 and TnK6 on the concentration of lactate,the concentration of VFA and C2/C3 could establish the foundement for developing the microecosystem preparation of Selenomonas ruminantium and open up a new path to prevente disorders of energy metabolism in periparturient dairy cows.