The metabolism of tartaric acid by Penicillium charlesii

Abstract

It was found that Penicillium charlesii metabolized 60–80% of all carbon atoms in dl-tartaric acid to carbon dioxide by 19 days after inoculation into a growth medium containing 32 m m l-tartaric acid, 278 m m d-glucose, and a mineral salts solution. A large fraction (80–90%) of the 14C-labeled substances derived from tartrate, present in the mycelia after a 19-day growth period, was extracted into trichloracetic acid. Less than 1% of the labeled tartaric acid taken up by the organism was incorporated into protein. It was concluded that tartaric acid was not metabolized via a tartaric acid dehydratase-catalyzed reaction because aspartic acid derived from dl-tartrate-2,3- 14C had slightly more than twice the specific activity of aspartic acid derived from dl-tartrate-1,4- 14C. No tartrate dehydratase could be detected in any of the enzyme extracts. However, the organism contained enzymes capable of converting l-tartrate to glyceric acid, while an NAD-specific l-tartrate oxidoreductase and an NADPH-specific hydroxypyruvate oxidoreductase activity were demonstrated.