Metabolism of pyrimidine bases and nucleosides in the coryneform bacteria Brevibacterium ammoniagenes and Micrococcus luteus

The metabolism of exogenous pyrimidine bases and nucleosides was investigated in Brevibacterium ammoniagenes and Micrococcus luteus with fluorinated analogs and radioactive precursors. Salvage of thymine and thymidine was found in M. luteus, but not in B. ammoniagenes. Exogenous uracil or uracil nucleosides, but not cytosine or cytosine nucleosides, were nucleic acid precursors for both bacteria. By examining the possible nucleoside-metabolizing enzymes, it can be suggested that the pyrimidine salvage pathways in the coryneform bacteria are different from those of members of the family Enterobacteriaceae.</jats:p

Evaluation of different approaches for identification of xenobiotic- degrading pseudomonads

Different approaches were evaluated to identify aerobic, gram-negative, biodegradative isolates assumed to be pseudomonads. Quinone and polyamine analysis allowed rapid identification to the genus level, i.e., allocation of those isolates belonging to the Pseudomonas fluorescens complex which represents the phylogenetically defined core of the heterogeneous genus Pseudomonas. Subsequent studies concentrated only on these true pseudomonads. The multiple-test system API 20NE, determination of the moles percent G+C content, and polyacrylamide gel electrophoresis of soluble proteins aided in identification on the species level. Polyacrylamide gel electrophoresis of both soluble proteins and whole-cell lipopolysaccharides allowed recognition of identical strains and double isolates, which were confirmed by DNA-DNA hybridization.</jats:p