Determination of the carbon content of biomass. A prerequisite to estimate the complete biodegradation of polymers
Bestimmung des Biomassekohlenstoffes. Eine Voraussetzung zur Abschätzung der vollständigen biologischen Abbaubarkeit von Polymeren
This article presents a method to determine the carbon content of biomass, which is formed when degrading biodegradable polymers in an aerobic aqueous test-system. Existing methods for determining the carbon content of biomass (e.g. fumigazation, protein assays, dry solids) have several disadvantages when applied for polymer degradation tests. In this work a protein assay based on the Lowry method (1) was used. It was shown that thr ratio between protein and carbon content is not constant but depends on the composition of the microbial population, the growth phase, and on the substrate supply. This effect was used for the method presented in this article. For determining the carbon content of biomass the absorbance obtained by the Lowry test is correlated directly with the carbon content of biomass in dependence of the duration of the degradation test. The calibration curves are obtained by a mixed population of microorganisms during the course of a degradation test.