TY - JOUR
T1 - Relationship between structures of substituted indolic compounds and their degradation by marine anaerobic microorganisms
AU - Gu, Ji Dong
AU - Fan, Yanzhen
AU - Shi, Hanchang
N1 - Funding Information:
This research was supported by the Visiting Scholar Foundation of Key Laboratory at Tsinghua University to Gu. Additional support was by the Chinese Academy of Sciences and the CRCG grant of The University of Hong Kong.
PY - 2002/9
Y1 - 2002/9
N2 - Degradation of selected indolic compounds including indole, 1-methylindole, 2-methylindole, and 3-methylindole was assessed under methanogenic and sulfate-reducing conditions using the serum-bottle anaerobic technique and marine sediment from Victoria Harbour, Hong Kong as an inoculum. Our results showed that indole degradation was achieved in 28 days by a methanogenic consortium and 35 days by a sulfate-reducing consortium. During degradation under both conditions, two intermediates were isolated, purified and identified as oxindole and isatin (indole-2,3-dione) suggesting that both methanogenic and sulfate-reducing bacteria use an identical degradation pathway. Degradation processes followed two steps of oxidation accomplished by hydroxylation and then dehydrogenation at 2- and then 3-position sequentially prior to the cleavage of the pyrrole ring between 2- and 3-positions. However, none of 1-methylindole or 2-methylindole was degraded under any conditions. 3-Methylindole (3-methyl-1H-indole, skatole) was transformed under methanogenic conditions and mineralized only under sulfate-reducing conditions. It is clear that methyl substitution on 1- or 2-position inhibits the initial attack by hydroxylation enzymes making them more persistent in the environment and posing longer toxic impact.
AB - Degradation of selected indolic compounds including indole, 1-methylindole, 2-methylindole, and 3-methylindole was assessed under methanogenic and sulfate-reducing conditions using the serum-bottle anaerobic technique and marine sediment from Victoria Harbour, Hong Kong as an inoculum. Our results showed that indole degradation was achieved in 28 days by a methanogenic consortium and 35 days by a sulfate-reducing consortium. During degradation under both conditions, two intermediates were isolated, purified and identified as oxindole and isatin (indole-2,3-dione) suggesting that both methanogenic and sulfate-reducing bacteria use an identical degradation pathway. Degradation processes followed two steps of oxidation accomplished by hydroxylation and then dehydrogenation at 2- and then 3-position sequentially prior to the cleavage of the pyrrole ring between 2- and 3-positions. However, none of 1-methylindole or 2-methylindole was degraded under any conditions. 3-Methylindole (3-methyl-1H-indole, skatole) was transformed under methanogenic conditions and mineralized only under sulfate-reducing conditions. It is clear that methyl substitution on 1- or 2-position inhibits the initial attack by hydroxylation enzymes making them more persistent in the environment and posing longer toxic impact.
KW - Anaerobic degradation
KW - Indole
KW - Metabolic pathway
KW - Methanogenic condition
KW - Substitution
KW - Sulfate-reducing condition
UR - http://www.scopus.com/inward/record.url?scp=0036741558&partnerID=8YFLogxK
U2 - 10.1016/S0025-326X(02)00091-7
DO - 10.1016/S0025-326X(02)00091-7
M3 - 文章
C2 - 12398409
AN - SCOPUS:0036741558
SN - 0025-326X
VL - 45
SP - 379
EP - 384
JO - Marine Pollution Bulletin
JF - Marine Pollution Bulletin
IS - 1-12
ER -