Production and Characterization of Antimicrobial agents by Lactic Acid Bacteria Isolated from Fermented Foods
A Rebecca, B Mobolaji, O Janet
antagonistic activity, antimicrobials, fermented foods, growth media, lactic acid bacteria
A Rebecca, B Mobolaji, O Janet. Production and Characterization of Antimicrobial agents by Lactic Acid Bacteria Isolated from Fermented Foods. The Internet Journal of Microbiology. 2007 Volume 4 Number 2.
Twenty-six lactic acid bacteria isolated from fermented foods and beverages consumed in Southwestern Nigeria were screened for antimicrobial agents production. Twenty-one isolates produced bacteriocin while 5 did not; hence the non-bacteriocin producing strains were used for antimicrobial assay. Hydrogen peroxide produced by
Lactic acid bacteria (LAB) are the most prominent non-pathogenic bacteria that play a vital role in our everyday life, from fermentation, preservation, and production of wholesome foods, and vitamins to prevention of certain diseases and cancer due to their antimicrobial action. Lactic acid fermentation is generally inexpensive often requiring little or no heat in the process, making them fuel-efficient as well (Keith, 1991). These microorganisms are one of the prominent bacteria inhabiting the gastrointestinal tract, and the importance of these non-pathogenic bacteria has recently been more noticed (Englund, 1992). A lot of Lactobacilli have been noted to have nutritional benefits, improved lactose utilization, have anti cholesterol, anti carcinogenic activities, and protection against other diseases (Englund, 1992; Reddy et al., 1984; Abdel-Bar et al., 1987).
Apart from the above-mentioned medicinal importance of Lactobacilli, it also helps in the control of intestinal pathogens. For instance
However, studies relating to the antibacterial properties of these organisms have been limited and not fully exploited for use. Two of the most important aspects in the study of antimicrobials are their production and characterization. Therefore, this paper reports the production and characteristics of antimicrobials produced by lactic acid bacteria isolated from fermented foods.
Materials and Methods
Results and Discussion
Davidson et al., (1983) stated that H2O2 production is common in microorganism that do not produce catalase but possess flavoprotein oxidases that react with dioxide. Hydrogen peroxide could in some cases be a precursor for the production of other potent antimicrobial species such as super oxide (O2-) and hydroxyl (OH-) radicals (Condon, 1987, Thomas and Pera, 1983).
The question of production cost is an important issue to be taken into account when large-scale production of antimicrobials for use as a food preservative is considered. Our results showed that antimicrobials could be produced in a relatively inexpensive and readily available medium.
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