Screening Of Functional Microorganisms

In ruminants,the extensive using of antibiotics has led to an enhanced resistance to pathogens in animals,which increases the difficulty of treating animal disease and has an adverse effect on the development of animal husbandry.There are resourceful microbes in the rumen that are beneficial of the digestion and absorption to body of animal and the promotion of immune function.To reduce the using of antibiotics in the fodder,adding the functional microorganisms to the feed has a vital importance for animal husbandry.In this study,the rumen was taken from sheep,and the strains were screened through cell enrichment and purification.The enzyme was identified and the enzyme activity was determined to screen the microorganisms with the ability to produce enzyme.In order to screen out the microbes with antibacterial activity,the inhibitory ability of the indicator bacteria,such as Vibrio parahaemolyticus,Aerogenes,Escherichia coli and Sarcina lutea,was identified by the use of strains.Four strains were identified by Gram stain and morphological characterization,and the oxygen resistance,acid resistance and bile resistance of the strain were tested.From the sheep rumen,31 strains of bacteria and 12 fungi were screened.By enzymatic identification of the celllase,amylase,protease and lipase,and the determination of enzyme activity,23 strains producing cellulase show more cellulase enzyme activity,especially the enzyme activity of strain C22 reached to 3.84 U/mL.12 strains producing amylase show more amylase enzyme activity,especially the enzyme activity of strain C10 reached to 23.13 U/mL,and the enzyme activity of strain C21 reached to 21.88 U/mL.13 strains producing protease show more protease enzyme activity,especially the enzyme activity of strain C10 reached to 47.20 U/mL,and the activity of lipase in strain was the weaker.The inhibitory ability of strain C18 to Vibrio parahaemolyticus was the strongest,and strain C7 had the strongest inhibitory effect on Aerogenes.Strain C21 and strain C22 had the strongest inhibitory effect on Escherichia coli,and strain C8 and strain C10 had the strongest inhibitory effect on the Sarcina lutea.The strains CIO,C18,C21,C22 of excellent performance were further identified.The results showed that Four strains were facultative anaerobic bacillus,strain C18 and strain C21 were Bacillus.Strains C18,C21 and C22 were Gram-positive bacteria,strain CIO was Gram-negative bacteria.The survival rate of the four strains was above 90%at the pH of 5,and the survival rate in the 0.1%porcine salt solution was above 80%.