Biokinetic parameters and behavior of Aeromonas hydrophila during anaerobic growth

The biokinetics of glucose metabolism were evaluated in Aeromonas hydrophila during growth in an anaerobic biosystem. After approx 34 h growth, A. hydrophila metabolized 5,000 mg glucose l(-1) into the end-products ethanol, acetate, succinate and formate. The maximum growth rate, mu(m), half saturation coefficients, K(s), microbial yield coefficient, Y, cell mass decay rate coefficient, k(d), and substrate inhibition coefficient, K(si) were 0.25 +/- 0.03 h(-1), 118 +/- 31 mg glucose l(-1), 0.12 microg DNA mg glucose(-1), 0.01 h(-1), and 3,108 +/- 1,152 mg glucose l(-1), respectively. These data were used to predict the performance of a continuous growth system with an influent glucose concentration of 5,000 mg l(-1). Results of the analysis suggest that A. hydrophila will metabolize glucose at greater than 95% efficiency when hydraulic retention times (HRTs) exceed 7 h, whereas the culture is at risk of washing out at an HRT of 6.7 h.