Influence of complex nutrients, temperature and pH on bacteriocin production by Lactobacillus sakei CCUG 42687

Abstract

The effects of process conditions and growth kinetics on the production of the bacteriocin sakacin P by Lactobacillus sakei CCUG 42687 have been studied in pH-controlled fermentations. The fermentations could be divided into phases based on the growth kinetics, phase one being a short period of exponential growth, and three subsequent ones being phases of with decreasing specific growth rate. Sakacin P production was maximal at 20 degrees C. At higher temperatures (25-30 degrees C) the production ceased at lower cell masses, when less glucose was consumed, resulting in much lower sakacin P concentrations. With similar media and pH, the maximum sakacin P concentration at 20 degrees C was seven times higher than that at 30 degrees C. The growth rate increased with increasing concentrations of yeast extract, and the maximum concentration and specific production rate of sakacin P increased concomitantly. Increasing tryptone concentrations also had a positive influence upon sakacin P production, though the effect was significantly lower than that of yeast extract. The maximum sakacin P concentration obtained in this study was 20.5 mg l(-1). On the basis of the growth and production kinetics, possible metabolic regulation of bacteriocin synthesis is discussed, e.g. the effects of availability of essential amino acids, other nutrients, and energy.

Production, stability, gene sequencing and in situ anti-Listeria activity of mundticin KS expressed by three Enterococcus mundtii strains

“…Furthermore, bacteriocin production can be influenced by the culture conditions . It is reported that bacteriocin activities do not always correlate with cell concentration or growth rate of the producer (Kim, Hall, & Dunn, 1997), as well as that higher levels of bacteriocin production may be obtained in sub-optimal conditions (Aasen, Moretro, Katla, Axelsson, & Storro, 2000;Todorov & Dicks, 2004). On the contrary, found that stressing conditions and lack or low concentrations of nutritional factors determined a reduction in bacteriocin production by several E. mundtii strains.…”

“…Type and concentration of carbon and nitrogen sources are relevant for bacteriocin production (Delgado et al, 2007). Several authors reported that higher bacteriocin activities are observed with increased nitrogen concentrations (Aasen et al, 2000;Kim et al, 1997).…”

Lactic acid bacteria protect human intestinal epithelial cells from Staphylococcus aureus and Pseudomonas aeruginosa infections

“…Lactic acid bacteria comprise a group of Gram-positive, non-sporulating rods or cocci, which produce lactic acid as the major end-product of carbohydrate fermentation (Aasen et al, 2000;Suskovic et al, 2001). These bacteria produce a variety of antimicrobial compounds (Bongaerts and Severijnen, 2001;Servin, 2004) such as organic acids, diacetyl compounds, and hydrogen peroxide during lactic fermentation (Lindgren and Dobrogosz, 1990).…”

Medium Optimization for Bacteriocin Production and Bacterial Cell Growth of Geobacillus sp. 15 Strain

“…Bacteriocin production is usually growth associated, i.e. the level at which the peptide is produced is linked to the biomass formed [19,[24][25][26][27]. Some studies have indicated that bacteriocin production and activity levels do not always correlate with cell mass or growth rate of the producer strain [26,28].…”

“…The effects of medium composition for bacteriocin production have been studied for pediocin AcH [14], pediocin PD-1 [15], enterocin P [16], nisin [17], plantaricin 423 [18], and sakP [19]. Bacteriocin production may be strongly influenced by carbon sources, nitrogen sources, inorganic salts, temperature and pH [20][21][22][23].…”