Watanabe Kimiko, Noda Ken-ichi, Konishi Jin, Maruhashi Kenji
Bio-Refining Process Laboratory, Technical Cooperation Department, Japan Cooperation Center, Petroleum, 58F Sun-shine 60, 3-1-1 Ikebukuro, Toshima-ku, Tokyo 170-6058, Japan.
Biotechnol Lett. 2003 Sep;25(17):1451-6. doi: 10.1023/a:1025020003953.
Recombinant Mycobacterium sp. strain MR65 harboring dszABCD genes was used to desulfurize alkyl dibenzothiophenes (Cx-DBTs) in n-hexadecane. The specific desulfurization activity for 2,4,6,8-tetraethyl DBT (C8-DBT) by DszC enzyme was about twice that for 4,6-dipropyl DBT (C6-DBT). However, the degradation rate of 2,4,6,8-tetraethyl DBT in n-hexadecane by resting cells of strain MR65 was only about 40% of that of 4,6-dipropyl DBT. These results indicated that the desulfurization ability for Cx-DBTs by resting cells depends on carbon number substituted at positions 4 and 6 and that the rate-limiting step in the desulfurization reaction of highly alkylated Cx-DBTs is the transfer process from the oil phase into the cell.
携带dszABCD基因的重组分枝杆菌菌株MR65被用于对正十六烷中的烷基二苯并噻吩（Cx-DBTs）进行脱硫。DszC酶对2,4,6,8-四乙基二苯并噻吩（C8-DBT）的比脱硫活性约为对4,6-二丙基二苯并噻吩（C6-DBT）的两倍。然而，菌株MR65的静息细胞对正十六烷中2,4,6,8-四乙基二苯并噻吩的降解率仅约为4,6-二丙基二苯并噻吩的40%。这些结果表明，静息细胞对Cx-DBTs的脱硫能力取决于4位和6位取代的碳原子数，并且高度烷基化的Cx-DBTs脱硫反应中的限速步骤是从油相到细胞的转移过程。
