Isolation and characterization of bacteria degrading chlorinated organophosphate esters, persistent organophosphorus compounds

降解氯化有机磷酸酯、持久性有机磷化合物的细菌的分离和表征

• 批准号: 16310054
• 负责人: KERA Yoshio
• 金额: $ 10.15万
• 依托单位: Nagaoka University of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2004
• 资助国家: 日本
• 起止时间: 2004 至 2007
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-16310054/
• 关键词: persistent organic compounds; chlorinated compounds; organophosphate esters; tris(1,3-dichloro-2-propyl)phosphate; tris(2-chloroethyl) phosphate; biodegradation; Tris (1,3-dichloro-2-propy1)phosphate; Tris (2-chloroethy1)phosphate; 分解微生物; 難分解性

Organophosphate esters(OPEs) constitute the predominant group of phosphorus-containing flame-retardants and plasticizers, as well as of agricultural pesticides and herbicides. These OPE flame-retardants and plasticizers are widely used worldwide in diverse materials, such as plastics, polymeric foams, rubbers, textiles and building materials. Among them, chlorinated organophosphate esters, such as tris(2-chloroethyl) phosphate (TCEP) or tris(1,3-dichloro-2-propyl) phosphate (TDCPP) have several toxic effects including carcinogenic and immunotoxic activities. However, microorganisms or enrichment culture capable of readily degrading the chlorinated OPEs have not been reported.In this study, for the first time, we succeed in obtaining two mixed bacterial cultures capable of rapidly degrading both TCEP and TDCPP by enrichment using each compound as the sole phosphorus source, and analyzed their degradation ability and generated metabolites. Then we isolate two bacteria from the mixed bacterial cultures, and identified and designated them as Sphingomonas sp. strain TDK1 and Sphingobium sp. strainTCM1. Both strains can degrade TDCPP and TCEP.In the degradation of TCEP and TDCPP, we detected 2-chloroethanol (2-CE) and 1,3-dichloro-2-propanol (1,3-DCP) as a metabolite by a gas chromatography-mass spectroscopy (GC-MS) analysis, respectively. This is the first report that the chloroalcohols were produced as a metabolite of the chlorinated OPEs by microbial degradation and indicated the cleavage of phosphoester bond in their degradation pathways.The phosphoesterase, the enzyme catalyzing the first step of the degradation of TDCPP and TCEP, were localized the soluble fraction of the bacterial cell. We purified the enzyme 68-fold from cell-free extracts of Sphingobium sp. strainTCM1, to near homogeneity. The enzyme is a monomer and molecular mass was 62.7 kDa.

有机磷酸酯（OPEs）构成含磷阻燃剂和增塑剂以及农业杀虫剂和除草剂的主要组。这些OPE阻燃剂和增塑剂在全球范围内广泛用于各种材料，如塑料、聚合物泡沫、橡胶、纺织品和建筑材料。其中，氯化有机磷酸酯，如三（2-氯乙基）磷酸酯（TCEP）或三（1，3-二氯-2-丙基）磷酸酯（TDCPP）具有多种毒性作用，包括致癌和免疫毒性活性。本研究首次以TCEP和TDCPP为唯一磷源，通过富集获得了两株能够快速降解TCEP和TDCPP的混合菌，并分析了它们的降解能力和产生的代谢产物。从混合菌群中分离到两株细菌，经鉴定分别命名为鞘氨醇单胞菌TDK 1株和鞘氨醇杆菌TCM 1株。两株菌均能降解TDCPP和TCEP，通过气相色谱-质谱（GC-MS）联用分析，分别检测到2-氯乙醇（2-CE）和1，3-二氯-2-丙醇（1，3-DCP）作为代谢产物。这是首次报道氯代OPEs在微生物降解过程中产生氯代醇类化合物，并指出其降解途径中存在磷酸酯键的断裂，而催化TDCPP和TCEP降解的第一步酶磷酸酯酶定位于细菌细胞的可溶性组分中。我们从鞘氨醇菌属菌株TCM 1的无细胞提取物中纯化了68倍的酶，使其接近均一。该酶为单体，分子量为62.7 kDa。