Increased production of bacST4SA by Enterococcus mundtii in an industrial-based medium with pH-control
Date
2007-03
Journal Title
Journal ISSN
Volume Title
Publisher
Stellenbosch : University of Stellenbosch
Abstract
Lactic acid bacteria (LAB) are producers of bacteriocins, ribosomally synthesized
antimicrobial peptides. Bacteriocins are secreted into the surrounding environment where they
inhibit growth of other bacteria competing for the same nutrients in a particular environment,
usually closely related strains. Some of the bacteriocin-sensitive bacteria include food spoilers
and - pathogens, which makes bacteriocins potential natural food preservatives. The need for
more natural preservation techniques in the food industry is high: Consumers prefer ready-toeat,
minimally processed foods containing no chemical preservatives, but at the same time
food spoilage and food-related illnesses are areas of big concern. The antibacterial and
antiviral properties of some bacteriocins have also made them suitable for controlling
bacterial infections, e.g. as part of pharmaceutical ointments. The increasing rate of resistance
against antibiotics by micro-organisms has created a market for alternative treatments for
infections. Commercial bacteriocin manufacturing proceeds in controlled fermentations or by
extraction from plant material.
Enterococcus mundtii ST4SA produces a bacteriocin, bacST4SA, with properties giving it
potential for use as a food preservative or as part of a pharmaceutical product. In this study,
production of bacST4SA by fermentation of low-cost food-grade growth media, sugarcane
molasses, corn steep liquor (CSL) and cheese whey, was considered to increase the economic
viability of production for food application. Furthermore, individual de Man Rogosa and
Sharpe (MRS) medium components, pH and fed-batch fermentation were evaluated to
improve bacST4SA activity...
Description
Thesis (MScEng (Process Engineering))--University of Stellenbosch, 2007.
Keywords
Dissertations -- Process engineering, Theses -- Process engineering, Bacteriocins, Lactic acid bacteria