Identification and screening of antimicrobial activity of lactic acid bacteria isolated from dairy products

This study was conducted to screen for the antimicrobial activity of isolated LAB from dairy product and to identify the genera of the LAB. Four isolates of unknown bacteria were obtained from Mycology Laboratory at Biotech 2 with the permission from the supervisor. All the unknown bacteria were isolated from 4 diferrent resources of dairy product. Among four isolates, only one showed the clear zone in the screening of antimicrobial activity against Escherichia coli and Listeria monocytogenes. The isolate was labelled as sample 1, it showed rod shape under the microscope and was revealed as the gram positive bacteria due its appearace in purple colour on gram staining test. Presumption test was done on sample 1 with a few series of biochemical test and it was identified as Lactobacillus sp. The LAB was tested using critical dilution method to determine the quantitatively amount of the antimicrobial activity on E. coli and L. monocytogenes. Regarding to this finding, it can be further commercialized on fighting the food disease associated by food borne pathogen and and may involve in the food preservative method