Statistics for The fermentation reaction producing biosurfactant using Pseudomonas aeruginosa CFTR?6 was studied. The progress of the bioreaction was monitored in terms of biomass production, product formation and substrate consumption in shake flask experiments using different initial sugar concentrations. A logistic model for biomass growth was found to be satisfactory. Average estimates of the specific growth rate, biomass yield coefficient and maintenance coefficients were obtained. Copyright © 1991 Society of Chemical Industry