Microbial metabolism of the pyridine ring. Metabolism of 2- and 3-hydroxypyridines by the maleamate pathway in Achromobacter sp

Abstract

1. Washed suspensions of two Achromobacter species (G2 and 2L), capable of growth upon 2- and 3-hydroxypyridine respectively as sources of C and N, rapidly oxidized their growth substrate pyridine-2,5-diol (2,5-dihydroxypyridine) and the putative ring-cleavage product maleamate without a lag. Suspensions derived from fumarate plus (NH(4))(2)SO(4) cultures were unable to do so. 2. Extracts of both bacteria oxidized pyridine-2,5-diol with the stoicheiometry of an oxygenase forming 1mol of NH(3)/mol of substrate. 3. Heat-treated extracts, however, formed maleamate and formate with little free NH(3). 4. The conversion of maleamate into maleate plus NH(3) by extracts of strain 2L, fractionated with (NH(4))(2)SO(4), and the metabolism of maleamate and maleate to fumarate by extracts of both strains demonstrated the existence of the enzymes catalysing each reaction of the maleamate pathway in these bacteria. 5. The pyridine-2,5-diol dioxygenase (mol.wt. approx. 340000) in extracts of these Achromobacter species required Fe(2+) (1.7mum) to restore full activity after dialysis or treatment with chelating agents; the enzyme from strain 2L also had a specific requirement for l-cysteine (6.7mm), which could not be replaced by GSH or dithiothreitol. 6. The oxygenase was strongly inhibited in a competitive manner by the isomeric pyridine-2,3- and -3,4-diols.

Microbial degradation of pyridine by Paracoccus sp. isolated from contaminated soil

“…Since 1910s, researchers have isolated some microbial organisms degrading pyridine and its derivatives including hydroxypyridine, alkylpyridine and carboxypyridine, and elucidated microbial metabolic pathway of these compounds [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16]. There were some examples as following.…”

“…There were some examples as following. A group leaded by Cain [1,2,5,[9][10][11][12] from U.K. obtained some pure cultures with the ability to utilize pyridine as sole source of carbon, nitrogen and energy, and its hydroxy derivatives as principal carbon source by elective culture either from sewage of an activated-sludge plant or a few crumbs of soil. Five pure strains were selected for detailed study.…”

A 2-Hydroxypyridine Catabolism Pathway in Rhodococcus rhodochrous Strain PY11

“…Rhodococcus strains were grown at 30°C with aeration, and E. coli strains were grown at 37°C with aeration. Rhodococcus rhodochrous PY11 was cultivated either in nu-trient broth (NB) medium (Oxoid) or in minimal medium (5 [wt/vol]). E. coli cells transformed with recombinant plasmids were cultivated in NB medium supplemented with appropriate antibiotics (50 g/ml ampicillin, 20 g/ml streptomycin, or 40 g/ml kanamycin).…”

“…strain G2 (5), and Nocardia sp. strain PNO (6) use 2-hydroxypyridine (2HP) as a sole carbon and energy source.…”

Oxyfunctionalization of pyridine derivatives using whole cells of Burkholderia sp. MAK1

“…Several bacteria belonging to the genera Arthrobacter, Achromobacter, Rhodococcus , and Nocardia are able to grow on pyridin-2-ol32333435. The first common steps in the microbial metabolism of pyridin-2-ol involve the hydroxylation of the ring yielding di- or trihydroxypyridine intermediates323536 that are promising synthons for the preparation of substituted pyridines.…”