Biodesulfurization of naphthothiophene and benzothiophene through selective cleavage of carbon-sulfur bonds by Rhodococcus sp strain WU-K2R
Biodesulfurization of naphthothiophene and benzothiophene through selective cleavage of carbon-sulfur bonds by Rhodococcus sp strain WU-K2R
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DOI：
10.1128/aem.68.8.3867-3872.2002
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发表时间：
2002-08-01
影响因子：
4.4
通讯作者：
Usami, S
中科院分区：
文献类型：
--
作者：
Kirimura, K;Furuya, T;Usami, S
萘并[2，1-B]噻吩（NTH）是二苯并噻吩（DBT）的一种不对称结构异构体，除DBT衍生物外，加氢脱硫后的柴油中还含有NTH衍生物。红球菌属菌株WU-K2 R是从土壤中新分离的，因为其能够在以NTH作为唯一硫源的培养基中生长，并且生长的细胞在7天内降解0.27mM NTH。WUK 2 R也可以在以NTH砜、苯并噻吩（BTH）、3-甲基-BTH或5-甲基-BTH作为唯一硫源的培养基中生长，但不能利用DBT、DBT砜或4，6-二甲基-DBT。另一方面，WU-K2 R不利用NTH或BTH作为唯一的碳源。通过气相色谱-质谱分析，脱硫的NTH代谢产物被鉴定为NTH砜、2 '-羟基萘乙烯和萘并[2，1-B]呋喃。此外，由于脱硫的BTH代谢物被鉴定为BTH砜，苯并[c][1，2]氧硫杂环硫醚S-氧化物，苯并[c] [1，2]氧硫杂环硫醚S，S-二氧化物，o-羟基苯乙烯，2-（2 '-羟基苯基）乙烷-1-醛和苯并呋喃，因此可以得出结论，WU-K2 R通过硫特异性降解途径与碳-硫键的选择性断裂来脱硫NTH和BTH。因此，红球菌菌株WU-K2 R能通过硫特异性降解途径优先降解不对称杂环硫化合物如NTH和BTH，是一种独特的生物催化剂，表现出不同于DBT降解菌的特性。
Naphtho[2,1-b]thiophene (NTH) is an asymmetric structural isomer of dibenzothiophene (DBT), and in addition to DBT derivatives, NTH derivatives can also be detected in diesel oil following hydrodesulfurization treatment. Rhodococcus sp. strain WU-K2R was newly isolated from soil for its ability to grow in a medium with NTH as the sole source of sulfur, and growing cells of WU-K2R degraded 0.27 mM NTH within 7 days. WUK2R could also grow in the medium with NTH sulfone, benzothiophene (BTH), 3-methyl-BTH, or 5-methyl-BTH as the sole source of sulfur but could not utilize DBT, DBT sulfone, or 4,6-dimethyl-DBT. On the other hand, WU-K2R did not utilize NTH or BTH as the sole source of carbon. By gas chromatography-mass spectrometry analysis, desulfurized NTH metabolites were identified as NTH sulfone, 2'-hydroxynaphthylethene, and naphtho[2,1-b]furan. Moreover, since desulfurized BTH metabolites were identified as BTH sulfone, benzo[c] [1,2]oxathiin S-oxide, benzo[c] [1,2]oxathiin S,S-dioxide, o-hydroxystyrene, 2-(2'-hydroxyphenyl) ethan-1-al, and benzofuran, it was concluded that WU-K2R desulfurized NTH and BTH through the sulfur-specific degradation pathways with the selective cleavage of carbon-sulfur bonds. Therefore, Rhodococcus sp. strain WU-K2R, which could preferentially desulfurize asymmetric heterocyclic sulfur compounds such as NTH and BTH through the sulfur-specific degradation pathways, is a unique desulfurizing biocatalyst showing properties different from those of DBT-desulfurizing bacteria.