Department of Molecular and Chemical Life Sciences, Graduate School of Life Sciences, Tohoku University, Sendai, Japan.
Department of Materials Science and Bioengineering, Nagaoka University of Technology, Nagaoka, Niigata, Japan.
Biosci Biotechnol Biochem. 2023 Dec 19;88(1):123-130. doi: 10.1093/bbb/zbad141.
1,1,1-Trichloro-2,2-bis(4-chlorophenyl)-ethane (DDT) is the first synthetic insecticide and one of the most widely used pesticides. The use of DDT has been banned, but it remains one of the most notorious environmental pollutants around the world. In this study, we found that γ-hexachlorocyclohexane (γ-HCH) dehydrochlorinase LinA from a γ-HCH-degrading bacterium, Sphingobium japonicum UT26, converts DDT to 1,1-dichloro-2,2-bis(4-chlorophenyl)-ethylene (DDE). Because of the weak DDT degradation activity of LinA, we could not detect such activity in UT26 cells expressing LinA constitutively. However, the linA-deletion mutant of UT26 harboring a plasmid for the expression of LinA, in which LinA was expressed at a higher level than UT26, showed the DDT degradation activity. This outcome highlights the potential for constructing DDT-degrading sphingomonad cells through elevated LinA expression.
1,1,1-三氯-2,2-双(4-氯苯基)乙烷(滴滴涕)是第一种合成杀虫剂，也是使用最广泛的农药之一。滴滴涕的使用已被禁止，但它仍然是世界上最臭名昭著的环境污染物之一。在这项研究中，我们发现来自γ-六氯环己烷(γ-HCH)降解菌苏云金芽孢杆菌 UT26 的γ-六氯环己烷脱氯化氢酶 LinA 将滴滴涕转化为 1,1-二氯-2,2-双(4-氯苯基)乙烯(DDE)。由于 LinA 对滴滴涕的降解活性较弱，我们无法在持续表达 LinA 的 UT26 细胞中检测到这种活性。然而，携带表达 LinA 的质粒的缺失突变体 UT26，其 LinA 的表达水平高于 UT26，表现出滴滴涕的降解活性。这一结果突出了通过提高 LinA 表达来构建滴滴涕降解鞘氨醇单胞菌细胞的潜力。
