Metabolic characterisation of a novel vanillylmandelate-degrading bacterium
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- 作者：Janet E. Turner ; N. Allison and Charles A. Fewson
- 关键词：Key words Brevundimonas sp. ; Demethylation ; Dioxygenase ; Mandelic acid ; NAD ; dependent ; dehydrogenase ; Vanillylmandelic acid
- 刊名：Archives of Microbiology
- 出版年：1996
- 出版时间：October 1996
- 年：1996
- 卷：166
- 期：4
- 页码：252-259
- 全文大小：79 KB
文摘
A newly isolated gram-negative bacterium, possibly Brevundimonas diminuta, utilised d,l-vanillylmandelate (d,l-VMA) as a sole carbon and energy source. The organism converted d,l-VMA to vanillylglyoxylate using a soluble NAD-dependent dehydrogenase specific for d-VMA and a dye-linked, membrane-associated l-VMA dehydrogenase. Vanillylglyoxylate was further metabolised by decarboxylation, dehydrogenation and demethylation to protocatechuate. A 4,5-dioxygenase cleaved protocatechuate to 2-hydroxy-4-carboxymuconic semialdehyde. Partially purified d-VMA dehydrogenase exhibited optimal activity at 30¡ã C and pH 9.5 and had an apparent K m for d-VMA of 470 μM. Although induced by several substituted mandelates, the enzyme had a narrow substrate specificity range with virtually no activity towards d-mandelate. Such properties render the enzyme of potential use in both diagnostic and biosynthetic applications.