Purifications and properties of L-mandelate- 4-hydroxylase from Pseudomonas convexa

Microbial metabolism of mandelate: a microcosm of diversity

This review highlights the diversity of prokaryotic and eukaryotic microorganisms that can metabolise mandelate and it describes how a wide range of compounds related to mandelate is formed in many environments. The chief aspects that are summarised include the various pathways whereby mandelate and its structural analogues are converted into catechol or protocatechuate, the properties of the enzymes that are involved in the pathways, and the regulation and genetics of the pathways. The review incorporates the idea that the study of peripheral metabolic pathways is particularly useful for illuminating evolutionary speculations and it concludes with a list of questions that need to be answered.

Properties of a membrane-associated benzoate-4-hydroxylase from Rhodotorula graminis

Membrane fractions of benzoate-induced Rhodotorula graminis hydroxylated benzoate in the para position as demonstrated by high-performance liquid chromatography and isotopic thin-layer chromatography. Benzoate-4-hydroxylase activity was linear as a function of enzyme concentration (washed membranes) and time, and exhibited a pH optimum of 7.6. The enzyme utilized NADPH as a source of reducing equivalents, and was stimulated by FAD. The Km's for benzoate and NADPH were calculated as approximately 2.9 X 10(-5) M and approximately -1.9 X 10(-5) M, respectively. The particulate nature of benzoate-4-hydroxylase together with the fact that the enzyme was pteridine-independent indicates that it is distinct from the isofunctional enzyme previously described in filamentous fungi.