Effect of environmental factors in aerobiosis and anaerobiosis on the growth and activity of propionic acid bacteria evaluated by pressure measurement.

摘要

Propionibacterium shermanii CIP 10 30 27 was grown at pH 6.5 and 30degC with no added NaCl (designated optimal conditions) and under simulated cheese ripening conditions, e.g. pH 5.3 and 20degC, in the presence of NaCl at 2.1%, and the effects on of the atmosphere on growth were determined. Atmospheres tested comprised air, CO2 or N2. Results show that slowest growth occurred with a CO2 atmosphere, a decrease in the max. rate of pressure variation (Vmax,P) from 2.5 to 0.4 kPa/h and an increase in the lag phase from 3 to 80 h. In comparison to fermentation under the optimal conditions, during simulated cheese ripening production of propionate was increased, and the propionate to acetate ratio was higher.