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Study Of Some Characteristics Of Bacteriocins Produced From Locally Isolated Lactic Acid Bacteria | ||
| Journal of Tikrit University For Agriculture Sciences | ||
| Article 1, Volume 13, Issue 0, 2013, Pages 73-80 | ||
| Abstract | ||
| Some characteristics of bacteriocins produced from locally isolated Lactobacillus plantarum (LBP) (from pickles) and L. acidophilus (LBA) (from breast-fed baby feces) were studied. The inhibitory activity of the bacteriocins were evaluated on MRS agar against the tested bacteria using the well diffusion method. Results indicated that both bacteriocins were stable at a pH range of 4.0–6.0 for 168 hrs and the highest stability occurred at pH 5.0, however, they lost most of their activities at pH values less than 2 and more than 8. The LBP bacteriocin was also stable at 100C for 15 min and it lost 60% of its activity after 30 min exposure, while at temperatures of 50-60 C it was fairly stable at the same exposure time. On the other hand, LBA bacteriocin retained 76% of its activity when exposed for 30 min at a 70C and it lost all its activity at temperatures higher than 80C. Treatment of bacteriocins with low concentrations of sodium chloride or sodium lactate caused a slight loss of their activity while treatment with potassium chloride, magnesium sulfate or sodium carbonate caused a higher loss of bacteriocin activity even at low concentrations. However, treatment of bacteriocins with these salts at a concentration of 5% caused a complete loss of their activity. The two bacteriocins had lost their inhibitory activity upon treatment with the proteolytic enzyme trypsin, while they partially lost their activities when treated with pepsin. Other enzymes such as catalase, amylase or lipase did not affect the inhibitory activity of either bacteriocins. Key words: Lactic acid bacteria, bacteriocins, Lactobacillus plantarum, L. acidophilus. | ||
| Keywords | ||
| Characteristics; lactic acis; Lactobacillus plantarum; acidophilus | ||
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