Growth of the purple bacterium Rhodobacter capsulatus on the aromatic compound hippurate

The purple nonsulfur bacterium Rhodobacter capsulatus strain B10 grew photo trophically on the aromatic compound hippurate (N-benzoyl-L-glycine) and re lated benzoyl amino acids. Absorption spectra, extraction, and GC/MS analys is of culture supernatants showed that hippurate was stoichiometrically con verted to benzoate and glycine, with the latter used as a carbon or nitroge n source for growth. This conclusion was supported by detection of the enzy me hippuricase in permeabilized intact cells. Chemotrophic growth on hippur ate by Rba. capsulatus, either at full or reduced oxygen tensions, was not observed. The type strain of Rhodobacter sphaeroides as well as four strain s of Rhodopseudomonas palustris also grew phototrophically on hippurate, wh ile several other aromatic-degrading species of purple bacteria did not.