ABSTRACT
In bioremediation of polluted soils it is pollutant-mediated bacterial growth which determines efficiency of soil clean up. Growth means the production of biomass and to produce biomass, i.e. living matter, the bacteria use the organic carbon that is furnished by the organic pollutant. To manipulate the factors that may minimize the yield on hydrocarbons (gram of bacterial cells per gram of hydrocarbon used) or maximize the mineralization rate, requires an insight into various growth-associated phenomena. If large amounts of petroleum are spilled on the soil, soil bacteria could in principle grow under conditions of excess substrate. However, because of solubility of hydrocarbons which ranges from poor to practically insoluble, growth on hydrocarbons as a result of diffusion limitation may be linear and not logarithmic. Because hydrocarbons are unusual substrates for bacteria, bacterial growth on these peculiar organics deserve special attention. One aspect concerns the unusually large requirement for oxygen and the other aspect is related to the solubility of organics.
