MEMBRANE-COMPONENTS AND CELL FORM OF ACET OBACTOR POLYOXOGENES (VINEGAR PRODUCING STRAIN) UNDER HIGH ACIDIC CONDITIONS

Membrane components and cell form of A. polyoxogenes (vinegar producin g strain) under high acidic conditions were studied. A. polyoxogenes w as inoculated in the medium containing 6% of acetic acid, and the cult ure was continued until the acetic acid concentration in the medium re ached to 8, 12 and 19%. Composition of phospholipid component in the m icrobe membrane varied with an increase in the acetic acid concentrati on in the medium. The ratio of phosphatidylcholine increased and that of phosphatidylglycerol decreased as the acetic acid concentration inc reased. The ratio of phosphatidylethanolamine was little affected. Car dio-lipin was not detected during the fermentation period. Ratio of un saturated fatty acid in the total lipid was very high, and 86% of the total lipid was cis-vaccenate and its ratio was almost identical throu gh the fermentation. Proteins of A. polyoxogenes cell collected from t he broth at several fermentation stages were analyzed by electrophores is. Some differences were observed among proteins from soluble fractio ns but not among proteins from membrane fractions containing the enzym es of acetic acid fermentation. SEM of cells of A. polyoxogenes harves ted at each acidity showed that the cell obtained at 8 and 12% acetic acid concentration looked much shrinking and the cell obtained at 19% acetic acid concentration looked a normal form. These observations sug gest that cell wall also changed with acetic acid concentration. In co nclusion, membrane component ratio and cell wall structure of A. polyo xogenes changed according to change of acetic acid concentration in th e broth.