Investigation of the biodegradation process of a sythetic lubricant base stock

The biodegradation of the synthetic lubricant base stock Priolube 3999 was examined using several methods. The mineralization rate, the degradation determined by IR-spectroscopy (disappearance of CHsub3-CHsub2-groups), the formation of polar metabolites by DOC and the increase of the microbial biomass indicated by the DNA-content were measured. Differences of 33 40 percent were found in the determinations of the degradation by mineralization and IR-spectroscopy. These differences can be explained by the formation of polar metabolites and of microbial biomass. The suitability of several standardized test methods dependent on the substance is discussed.