Accelerated biodegradation of n-alkanes in aqueous solution by the addition of fermented whey

The effect of fermented whey on the aerobic degradation of n-alkanes by a microbial consortium was investigated in an aqueous system. Microbial degradation of 100 mg n-alkanes l−1 (C12, C14, C16 and C18) in mineral nutrient medium was assessed by measuring the decrease in n-alkanes, production of CO2 and increase in biomass. The addition of fermented whey at a concentration of 5 mg dry weight l−1 to a nutrient medium receiving a small-sized inoculum (103.4 CFU ml−1) shortened the lag phase from 8 to 3 days, but the degradation rate during the degradation phase was not enhanced. The shortened lag phase at low initial concentration of microorganisms indicates that the fermented whey stimulates growth in the initial phase, without reducing the consortium's capacity for n-alkane degradation.