Nwanekwu Kenneth Emeka

The inhibitory activity of bacteriocins produced by Lactic acid bacteria isolated from raw cattle and goat milk and other processed milk products against Mycobacterium bovis and Mycobacterium tuberculosis in milk was studied using spectrophotometry. Six bacteriocin positive strains of LAB were isolated and identified as Lactobacillus acidophilus, Lactobacillus casei, Lactobacillus fermentum, Lactobacillus brevis, Lactococcus lactis and Streptococcus thermophilus. The antimycobacterial activity of the bacteriocins in milk showed that the bacteriocins from Lactobacillus inhibited the growth of the mycobacterium over a period of 15 days while bacteriocin from Streptococcus did not inhibit the Mycobacteria in milk.  However, the activity of the bacteriocin were lost after the 15th day as shown by increase in absorbance on day 18. The bacteriocin mix from all six bacteriocins against Mycobacteria was the most efficient when compared to that of individual bacteriocins, recording a significant decline in absorbance at from 0.79 to 0.026 even on day 18.