Untersuchungen zum Stoffwechsel des anaeroben Alkanabbaus

Abstract

Strain HxN1, an Azoarcus-like denitrifying bacterium, degrades the saturated hydrocarbon n-hexane under anoxic conditions. Former studies on metabolites formed during the anaerobic degradation of n-alkanes suggested an activation mechanism analogous to that in the anaerobic degradation of toluene. The postulated enzyme (Mas, methylpentylsuccinate-synthase) is expected to belong to the class of glycyl radical enzymes. It was biochemically characterized by an enzymatic study using cell-free extract of strain HxN1. Furthermore, the enzyme was successfully purified under strictly anoxic conditions proofing the predicted function of the enzyme. A fourth by then unknown subunit of the enzyme was identified. Homologues of this subunit could be found in other n-alkane degrading organisms as well. Another part focused on the relationship of different mas-genes. In three strains tentative n-alkane activating genes could be identified strongly related to methylpentylsuccinate-synthase.