Inhibition by Acetic and Propionic Acids of the Growth of Propionibacterium shermanii

概要

論文の詳細を見る
First, optimum culture conditions for the growth of Propionibacterium shermanii on a glucose complex medium were studied in a turbidostat culture, maintaining the cell concentration at a very low level, 30 mg dry cell/l. Hence the inhibitory effects of the acetic and propionic acids produced upon the growth could be eliminated. The potimum cluture conditions for growth were at 30±2℃ and pH 6±1 with a small addition of Tweenn 80,0.1 g/l.Second, the inhibitory effects of acetic and propionic acids on growth were studied in the same turbidostat culture by feeding the same medium supplemented with acetic or propionic acid at various concentrations. Propionic but not acetic acid severly inhibited the growth, especially in acidic conditions. When the pH was maintained at 5.2,almost no growth was observed at 0.1 M propionate in the culture broth. It was suggested that a high concentration of undissociated propionic acid in acidic conditions might cause inhibition of the becterial growth.A mode of inhibition kinetics by both acids on growth could be categorized by a generalized non-competitive inhibition equation.[numerical formula]where P : concentration of acetic or propionic acid, K<P> : inhibition constant, 692 mM for acetate and 2 mM for undissociated propionate, n : exponent of inhibition, 2 for acetic acid and 1 for propionic acid, μ : specific growth rate, and μm : maximum of μ, 0.17h_<-1>.
社団法人日本生物工学会の論文
1983-12-25