Ethyl tert-butyl ether (EtBE) degradation by an algal-bacterial culture. EtBE degradation by an algal-bacterial culture

EtBE is a fuel oxygenate, made out of (bio)ethanol replacing MtBE. Biodegradation of EtBE can reduce the risk after accidental release in the environment. The oxygen produced by Scenedesmus and Chlorella was used by microorganisms to degrade EtBE using a P450 monooxygenase cytochrome. Metabolites formed during the micro-oxic EtBE degradation were tert-butyl alcohol (TBA), ethanol and CO2 determined using 13C nuclear magnetic resonance spectroscopy (NMR) and gas chromatography. Stable isotope probing (SIP) of the 13C and 12C enriched EtBE fractions showed no significant difference between phylotypes, including Halomonadaceae, Shewanellaceae, Rhodocyclaceae, Oxalobacteraceae, Comamonadaceae, Sphingomonadaceae, Hyphomicrobiaceae, Candidatus Moranbacteria, Omnitrophica, Anaerolineaceae, Nocardiaceae, and Blastocatellaceae. This study is the first study describing micro-oxic degradation of EtBE by an algal-bacterial culture.

乙基叔丁醚（Ethyl tert-Butyl Ether，简称EtBE）是一类燃料含氧化合物，以（生物）乙醇为原料制备，用以替代甲基叔丁基醚（Methyl tert-Butyl Ether，简称MtBE）。EtBE意外释放进入环境后，其生物降解作用可降低相关环境风险。栅藻（Scenedesmus）与小球藻（Chlorella）产生的氧气，可被微生物借助P450单加氧酶细胞色素（cytochrome P450 monooxygenase）用于EtBE的降解。本研究通过13C核磁共振波谱法（13C nuclear magnetic resonance spectroscopy，简称NMR）与气相色谱法，鉴定出微好氧条件下EtBE降解过程中生成的代谢产物为叔丁醇（tert-butyl alcohol，简称TBA）、乙醇与二氧化碳（CO₂）。对富集了13C与12C的EtBE组分开展稳定同位素探针（Stable isotope probing，简称SIP）分析后发现，包括盐单胞菌科（Halomonadaceae）、希瓦氏菌科（Shewanellaceae）、红环菌科（Rhodocyclaceae）、草酸杆菌科（Oxalobacteraceae）、丛毛单胞菌科（Comamonadaceae）、鞘氨醇单胞菌科（Sphingomonadaceae）、生丝微菌科（Hyphomicrobiaceae）、候选Moranbacteria菌门（Candidatus Moranbacteria）、Omnitrophica菌门、厌氧绳菌科（Anaerolineaceae）、诺卡氏菌科（Nocardiaceae）以及芽囊杆菌科（Blastocatellaceae）在内的各类系统发育型之间无显著差异。本研究为首项报道藻菌共培养体系在微好氧条件下降解EtBE的学术研究。