Quantification of Factors Which Influence Nisin's Inhibition of CIostridium botulinum 56A in a Model Food System

Abstract

We modeled nisin's anticlostridial activity and assessed the antagonistic or potentiating influences of food ingredients. The model systems contained yeast extract, proteose peptone, and ,glucose; were supplemented with protein (0.075, 0.75, 7.5% w/v), phospholipid (0.075, 0.75, 7.5% w/v), or soluble starch (5, 17.5, 30% w/v); and were adjusted to pH 5.5, 6.0, or 6.5. Samples inoculated with 104/mL spores were incubated at 15, 25, or 35°C. Statistical analysis developed an equation (r* = 0.76) that modeled the response and identified temperature as the most significant (a s 0.001) variable. Nisin lost effectiveness with increasing temperature. Nisin concentration had significant positive and phospholipid negative, linear effects. Many interactive effects were significant (a < 0.20). Nisin inhibited C. botulinurn until its residual level dropped below a threshold, which decreased from 154 IU/mL at 35°C to 12 IU/mL at 15°C.

Antibacterial efficacy of Nisin, Pediocin 34 and Enterocin FH99 against Listeria monocytogenes and cross resistance of its bacteriocin resistant variants to common food preservatives

“…Several studies focused in the application of potential synergists of nisin’s activity. These included the use of nitrites, low pH, pasteurization, controlled atmosphere, and food ingredients (Rayman et al , 1981; Somers and Taylor, 1981; Taylor et al , 1981; Taylor et al , 1985; Motlagh et al , 1992; Rogers and Montville, 1994; Scott and Taylor, 1998a, 1998b) but these reports lacked the data regarding the possible emergence of nisin resistant strains. There are only few reports on the development of intrinsic resistance to other preservation factors.…”

Nisin‐resistant (Nisr) Listeria monocytogenes and Nisr Clostridium botulinum Are Not Resistant to Common Food Preservatives

“…Several studies focused in the application of potential synergists of nisin's activity. These included the use of nitrites, low pH, pasteurization, controlled atmosphere, and food ingredients (Scott and Taylor 1981a,b;Somers and Taylor 1981;others 1985 and1990;Rayman and others 1981;Rogers and Montville 1994). These reports did not consider the possible emergence of nisin resistant strains.…”

Analysis of the Influence of Environmental Parameters on Clostridium botulinum Time-to-Toxicity by Using Three Modeling Approaches

“…The methods and techniques used to obtain the data used in our analysis are summarized below and were fully detailed by Rogers and Montville (29) and Rogers (28). C. botulinum 56A spores were cultured in a basal medium consisting of 1.0% (wt/vol) glucose (Sigma Chemical), 0.5% (wt/vol) peptone (Difco), 0.5% (wt/vol) yeast extract (Difco), and 0.01% (wt/vol) resazurin (Sigma).…”