TY - JOUR
T1 - Degradation of substituted indoles by an indole-degrading methanogenic consortium
AU - Gu, J. D.
AU - Berry, D. F.
PY - 1991
Y1 - 1991
N2 - Degradation of indole by an indole-degrading methanogenic consortium enriched from sewage sludge proceeded through a two-step hydroxylation pathway yielding oxindole and isatin. The ability of this consortium to hydroxylate and subsequently degrade substituted indoles was investigated. Of the substituted indoles tested, the consortium was able to transform or degrade 3-methylindole and 3-indolyl acetate. Oxindole, 3-methyloxindole, and indoxyl were identified as metabolites of indole, 3-methylindole, and 3-indolyl acetate degradation, respectively. Isatin (indole-2,3-dione) was produced as an intermediate when the consortium was amended with oxindole, providing evidence that degradation of indole proceeded through successive hydroxylation of the 2- and 3-positions prior to ring cleavage between the C-2 and C-3 atoms on the pyrrole ring of indole. The presence of a methyl group (-CH3) at either the 1- or 2-position of indole inhibited the initial hydroxylation reaction. The substituted indole, 3-methylindole, was hydroxylated in the 2-position but not in the 3-position and could not be further metabolized through the oxindole-isatin pathway. Indoxyl (indole-3-one), the deacetylated product of 3-indolyl acetate, was not hydroxylated in the 2-position and thus was not further metabolized by the consortium. When an H atom or electron-donating group (i.e., -CH3) was present at the 3-position, hydroxylation proceeded at the 2-position, but the presence of electron-withdrawing substituent groups (i.e., -OH or -COOH) at the 3-position inhibited hydroxylation.
AB - Degradation of indole by an indole-degrading methanogenic consortium enriched from sewage sludge proceeded through a two-step hydroxylation pathway yielding oxindole and isatin. The ability of this consortium to hydroxylate and subsequently degrade substituted indoles was investigated. Of the substituted indoles tested, the consortium was able to transform or degrade 3-methylindole and 3-indolyl acetate. Oxindole, 3-methyloxindole, and indoxyl were identified as metabolites of indole, 3-methylindole, and 3-indolyl acetate degradation, respectively. Isatin (indole-2,3-dione) was produced as an intermediate when the consortium was amended with oxindole, providing evidence that degradation of indole proceeded through successive hydroxylation of the 2- and 3-positions prior to ring cleavage between the C-2 and C-3 atoms on the pyrrole ring of indole. The presence of a methyl group (-CH3) at either the 1- or 2-position of indole inhibited the initial hydroxylation reaction. The substituted indole, 3-methylindole, was hydroxylated in the 2-position but not in the 3-position and could not be further metabolized through the oxindole-isatin pathway. Indoxyl (indole-3-one), the deacetylated product of 3-indolyl acetate, was not hydroxylated in the 2-position and thus was not further metabolized by the consortium. When an H atom or electron-donating group (i.e., -CH3) was present at the 3-position, hydroxylation proceeded at the 2-position, but the presence of electron-withdrawing substituent groups (i.e., -OH or -COOH) at the 3-position inhibited hydroxylation.
UR - http://www.scopus.com/inward/record.url?scp=0025809737&partnerID=8YFLogxK
U2 - 10.1128/aem.57.9.2622-2627.1991
DO - 10.1128/aem.57.9.2622-2627.1991
M3 - 文章
C2 - 1768136
AN - SCOPUS:0025809737
SN - 0099-2240
VL - 57
SP - 2622
EP - 2627
JO - Applied and Environmental Microbiology
JF - Applied and Environmental Microbiology
IS - 9
ER -