ENERGETIC AND NUCLEIC ANALYSES OF A CHEMOSTATIC CULTURE OF AZOTOBACTER VINELANDII

Abstract

With a chemostatic culture of Azotobacter vinelandii, the values of yield factor for glucose were measured; the measurement was repeated after steady state in each value of dilution rate could be realized. In parallel with the measurement of yield factor, the bacterial cells sampled in each run of steady state were processed properly to determine the nucleic materials such as DNA, RNA and specific substances, the latter of which could be dissolved in a cold perchloric acid solution.The glucose (limiting substrate) consumption by the cells was assumed to be a sum of that primarily due to cellular growth and that principally due to cellular maintenance. This assumption was justified experimentally. The efficiency of glucose utilization for cellular growth, YG, and the specific rate of glucose consumption for cellular maintenance, m, were 0.172 and 3.90 (hr-1), respectively.Although the contents of DNA and the acid-soluble substances remained fairly unchanged without regard to the values of dilution rate, a logarithmic relationship was confirmed between the RNA content, NR, and the value of dilution rate, D, or the specific growth-rate, μX, of the bacterium.