Lactic acid bacteria

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.

Lactic acid bacteria are a group of gram positive, non-sporing, cocci or bacilli, which produce lactic acid as the major end product in carbohydrate fermentations. Lactic acid bacteria were isolated from different diary sources . Disease causing pathogenic bacteria from clinical specimen were collected. Antimicrobial activity of the above pathogens were tested with a set of conventional antibiotics by the disk diffusion method. Antibacterial effects of the lactic acid bacteria against the above bacterial pathogens were done by agar well diffusion method. 10 pathogenic bacteria, resistant to minimum of three antibiotics  were selected for the study. Results of antibacterial activity of the lactic acid bacteria in the study revealed, a varying type of  inhibition, which was later used for comparison. The study was performed to check whether Lactic acid bacteria could be used in patients with antibiotic resistance.