Microcalorimetric investigation of effects of temperature on pH of petroleum bacterial optimum growth

The power-time curves for growth at different pH values of three strains of petroleum bacteria (B-1, B-2, B-3) at 40 and 50°C have been determined by using a 2277 Thermal Activity Monitor, and on the basis of the generalized logistic equation, a power–time curve equation, ln[αPK/P(t)−1]=ln[(αK−N0)/N0]−αkt, was proposed for calculating the growth and the death rate constants k, D, and nonlinear equations of k-pH, D-pH and (k−D)-pH were established for deciding the pH of optimum growth corresponding to the maximum values of k, (k−D) and the minimum value of D. The results indicated that the effect of temperature on pH of optimum growth was small.