Microbial transformation of benzothiophenes, with carbazole as the auxiliary substrate, by Sphingomonas sp strain XLDN2-5
Microbial transformation of benzothiophenes, with carbazole as the auxiliary substrate, by Sphingomonas sp strain XLDN2-5
复制标题
鞘氨醇单胞菌以咔唑为辅助底物对苯并噻吩进行微生物转化。
DOI：
10.1099/mic.0.2008/023176-0
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发表时间：
2008-12-01
期刊：
影响因子：
2.8
通讯作者：
Xu, Ping
中科院分区：
文献类型：
--
作者：
Gai, Zhonghui;Yu, Bo;Xu, Ping
苯并噻吩是煤焦油杂酚油中一种有毒且相对挥发的馏分。我们研究了咔唑（CA）降解菌鞘氨醇单胞菌XLDN 2 -5对苯并噻吩（BT）及其衍生物的共代谢转化，该菌不能以苯并噻吩为唯一碳源生长。在检测的苯并噻吩中，BT、2-甲基苯并噻吩（2-MBT）和5-甲基苯并噻吩（5-MBT）发生共代谢转化。对于3-甲基苯并噻吩，CA上的生长有完全的抑制。BT、2-MBT和5-MBT的常见转化产物是相应的亚砜和砜。对于BT，几种高分子量含硫芳族化合物，包括苯并[B]萘并[1，2-d]噻吩、苯并[B]萘并[1，2-d]噻吩-7-氧化物、6a，11 b-二氢苯并[B]萘并[1，2-d]噻吩、6a，11 b-二氢苯并[B]萘并[1，2-d]噻吩-7-氧化物和新产物6，1,2-环硫苯并[B]萘并[1，2-d]噻吩，这些高分子量产物被认为是由Diels-Alder型反应产生的。气相色谱和火焰离子化检测相结合的研究表明，约17%的BT转化为苯并[B]萘并[1，2-d]噻吩。苯并噻吩的好氧转化为亚砜和砜可以降低其毒性，促进其生物降解。然而，在苯并噻吩的生物降解过程中，应考虑到高分子量产物的生成，如苯并[B]萘并[1，2-d]噻吩。
Benzothiophenes are a toxic and relatively recalcitrant fraction of coal-tar creosote. We investigated the co-metabolic transformation of benzothiophene (BT) and its derivatives by the carbazole (CA) degrader Sphingomonas sp. XLDN2-5, which is not able to grow on benzothiophenes as the sole carbon source. Among the benzothiophenes tested, BT, 2-methylbenzothiophene (2-MBT) and 5-methylbenzothiophene (5-MBT) were co-metabolically converted. For 3-methylbenzothiophene, there was complete inhibition of growth on CA. The common transformation products for BT, 2-MBT and 5-MBT are the corresponding sulfoxides and sulfones. For BT, several high-molecular-mass sulfur-containing aromatic compounds, including benzo[b]naphtho[1,2-d]thiophene, benzo[b]naphtho[1,2-d]thiophene-7-oxide, 6a,11b-dihydrobenzo[b]naphtho[1,2-d]thiophene, 6a,11b-dihydrobenzo[b]naphtho[1,2-d]thiophene-7-oxide, and a new product, 6,12-epithiobenzo[b]naphtho[1,2-d]thiophene, were detected by GC-MS. These high-molecular-mass products are thought to be generated from a Diels-Alder-type reaction. Investigations with a combination of GC and flame ionization detection showed that about 17 % of BT was transformed to benzo[b]naphtho[1,2-d]thiophene. Aerobic transformation of benzothiophenes to sulfoxides and sulfones can reduce their toxicity, and facilitate their biodegradation. However, the formation of the high-molecular-mass products, such as benzo[b]naphtho[1,2-d]thiophene, should be considered in the biodegradation of benzothiophenes.