Commonwealth Scientific and Industrial Research Organisation Division of Food Processing, P.O. Box 52, North Ryde, New South Wales 2113, Australia.
Appl Environ Microbiol. 1989 Nov;55(11):2995-9. doi: 10.1128/aem.55.11.2995-2999.1989.
The rate of uptake of propanoic acid and the cell dimensions were measured for 23 yeasts differing in their resistance to weak-acid-type preservatives. Relationships between reciprocal uptake rate, reciprocal permeability, cell volume, cell area, volume/area, and the MICs of benzoic acid and propanoic acid for the yeasts were tested by correlation analysis on pairs of parameters. The MIC of methylparaben, which is not a weak-acid-type preservative, was included. The most significant relationships found were between both reciprocal uptake rate and reciprocal permeability and the MICs of propanoic and benzoic acids Cell volume, area, and volume/area were each individually correlated with propanoic and benzoic acid MICs, but less strongly. In multiple regression analyses, inclusion of terms for volume, area, or volume/area did not markedly increase the significance. The MIC of methylparaben was unrelated to the uptake and permeability parameters, but did show a correlation with cell volume/area. Schizosaccharomyces pombe was anomalous in having very low permeability. Exclusion of these outlying data revealed particularly strong relationships (P < 0.001) between both reciprocal uptake rate and reciprocal permeability and the benzoic acid MIC. MICs for Zygosaccharomyces bailii isolates were substantially higher than for the other species, and therefore Z. baillii isolates had a large influence on the regressions. However, the relationships observed remained significant even after removal of the Z. bailii data. In showing a correlation between the rate at which propanoic acid enters yeast cells and the ability of the cells to tolerate this and other weak-acid-type preservatives, but not methylparaben, the results suggest that the resistance mechanism, in which preservative is continuously removed from the cell, is a common and major determinant of the preservative tolerance of yeast species.
对 23 种在耐弱酸性防腐剂方面存在差异的酵母进行丙酸吸收速率和细胞尺寸的测定。通过对参数对的相关分析，检验了反向吸收速率、反向渗透性、细胞体积、细胞面积、体积/面积与苯甲酸和丙酸 MIC 值之间的关系。还包括了非弱酸性防腐剂对羟基苯甲酸甲酯的 MIC 值。发现的最显著关系是反向吸收速率和反向渗透性与丙酸和苯甲酸 MIC 值之间的关系。细胞体积、面积和体积/面积分别与丙酸和苯甲酸 MIC 值呈单独相关，但相关性较弱。在多元回归分析中，包含体积、面积或体积/面积项并没有显著增加其显著性。对羟基苯甲酸甲酯的 MIC 值与吸收和渗透性参数无关，但与细胞体积/面积呈相关关系。裂殖酵母的渗透性非常低，属于异常情况。排除这些异常数据后，发现反向吸收速率和反向渗透性与苯甲酸 MIC 值之间存在特别强的关系（P < 0.001）。酿酒酵母分离株的 MIC 值明显高于其他种，因此酿酒酵母分离株对回归有很大影响。然而，即使去除了酿酒酵母的数据，观察到的关系仍然具有显著性。由于丙酸进入酵母细胞的速率与细胞耐受这种和其他弱酸性防腐剂的能力之间存在相关性，而与对羟基苯甲酸甲酯无关，这表明防腐剂不断从细胞中被去除的抗性机制是酵母物种对防腐剂耐受性的一个常见且主要决定因素。
