Identification And Studying On Biological Characteristics Of Lactic Acid Bacteria Of Silage

With the development of animal husbandry, the applied research of silage has been attached extraordinarily in the resent years. The usage of silage and its newly scientific methods is more and more popular in animal husbandry, especially in developed country. The main function of Lactic acid bacteria is decreasing pH, depressing or killing the harmful microbiology through its fermentation. Therefore, improving fermentation qualities of silage and its nutritional value were the purpose of this research. Enhancing disease resistance of animal by using silage was also employed in present study.Lactic acid bacteria primarily obtained from silage. The optimum growing condition was defined as MRS cultural medium, 37℃, and anaerobic culture. Fourteen Lactic acid bacteria were selected at the first step. Nine lactobacilli were identified as homo-fermentative lactobacilli by lactate paper chromatography. The identified results by two experiment biochemical tests and esterase electrophoresis showed that X1, M16, N3 strains were L. brevis; S9, S7, LM1 and LM3 strains were L.. plantarum; N5,C15 were L. fermentus; while Y17 strain was not identified.Some fermentation qualities of nine bacteria were studied. Lactic acid bacteria were inoculated in MRS cultural medium, using bacteria suspension (3×106CFU/ml). The curve of growth of lactic acid bacteria, pH change of culture and the acid production were determined every two hours. The results showed the logarithm growth period and invariable period of lactic acid bacteria were 8~18h and after 24h respectively. The acid production was highly during 14~36h. The results suggested that LM3, S9 and N3 strains were superior in fermentation character by the comprehensive analysis, which could be used in fermented industry as zymophyte.The method of detecting lactobacilli by Oxford cup was developed in inhibiting bacteria test. Culture of nine bacteria centrifuged in 10,000 rpm/min. The supernatant were terminated by heating at 95℃for 5 min. Inhibiting bacteria test in vitro showed Staphylococcus, Escherichia coli, Salmonella, Aeromonas and Bacillus cereus were all inhibited by the nine lactic acid bacteria. X1,C15,LM3 had the most intensity function among the total. The supernatant of X1 and C15 strains were selected to extract sketchily, and the crude preparation were determined the existence of bacteriocin by SDS-PAGE. LM3 strain was selected in the fermentation test by its biological characteristics. 3% and 6% inoculating quantity of LM3 inoculated in the fresh corn cladophore and the empty. control sample was founded at the same time. The number of active bacteria in fermentation were examined every twenty days. The result showed that the active bacteria quantity in inoculated bacteria sample increased significantly compared with control sample , especially in 6% inoculating quantity group.