Lactic Acid Production and Tolerance Property of Lactic Acid Bacteria from Broiler Intestine / 微生物学通报

ABSTRACT

Lactic acid production of twelve strains of LAB isolated from broiler intestine and tolerance property of three strains were investigated. The results of lactic acid production showed that among all strains K6 exhibited the most rapid production during the first twelve hours, the seconds were K9 and C1; D17 exhibited the highest production of lactic acid by twenty-four hours, C1 exhibited the highest production of lactic acid by forty-eight hours. The pH values in three strains of K9、D17 and C1 culture showed the fast decline during the first twelve hours, with the final values significantly lower than those of other strains cultures. The results of tolerance property showed that the survival counts of C1could be detected when pH value was at 2 after three hours, but the survival counts of D17 and K9 could not be detected after one hour. When pH value was at 2.5 after three hours ,the survival counts of C1 declined from 10~ 8.2 /mL to 10~ 4.8 /mL, K9 from 10~ 8.2 /mL to 10~ 4.6 /mL, the survival counts of D17 could not be detected. 0.08% bile had few effects on the survival counts of three strains; when incubated in the medium with 0.40% bile, the survival counts of C1 declined from 10~ 8.4 /mL to 10~ 6.5 /mL,D17 from 10~ 10.3 /mL to 10~ 7.5 /mL, and K9 from 10~ 9.8 /mL to 10~ 7.7 /mL. When the group treated with 37℃ for 20 minutes was served as the control, the survival counts of C1 and K9 was not detected when treated with 80℃, but the survival counts of D17 were 10~ 4.9 /mL, when treatment with 65℃ the survival counts of C1 and K9 decreased significantly .