TITLE:
Antibacterial Activity of Lactic Acid Bacteria and Extraction of Bacteriocin Protein
AUTHORS:
Rabiul Islam, Md. Nur Hossain, Md. Khasrul Alam, Md. Ekhlas Uddin, Mehadi Hasan Rony, Md. Abu Sayeed Imran, Md. Firoz Alam
KEYWORDS:
Lactobacillus spp., Bacteriocin, Antimicrobial Activity, SDS PAGE, Biopreservative
JOURNAL NAME:
Advances in Bioscience and Biotechnology,
Vol.11 No.2,
February
26,
2020
ABSTRACT: Biopreservation systems
in foods are of increasing interest for industry and consumers. Bacteriocin producing Lactobacillus spp. is considered Generally Recognize as Safe
(GRAS), useful to control the fast development of pathogens and spoiling
microbes in food and feed. Lactobacillus spp. was isolated from traditional winter fermented vegetable cucumber & carrot
by the use of selective media. Especially De Man, Rogosa and Sharpe (MRS) Agar
media were used to isolate the Lactobacillus species. Morphologically identified by gram staining & colony morphology. Biochemically recognized by catalase, oxidase, MRVP & carbohydrate fermentation test. Antimicrobial activity of Lactobacillus
spp. was confirmed by Well Diffusion Method. Molecular characterization of bacteriocin protein and molecular weight
determined by SDS PAGE method. The isolate was found to be facultative anaerobic, Gram positive, and catalase negative. The result of antimicrobial activity measured by the Arbitrary Unit (AU/ml) of zone of the inhibition. Six isolates found from the sample but
most activities exhibited isolate 4 against Bacillus megaterium (55 mm) zone of diameter. The molecular weight
of the washed bacteriocin was calculated to be about 40 kDa (Isolate 1) and 15
kDa & 30 kDa (Isolate 5). Bacteriocin protein reduces chemical preservatives and uses in future as biopreservative in food industry.