Department of Civil and Environmental Engineering, FAMU-FSU College of Engineering, Florida State University, Tallahassee, FL, 32310, USA.
Department of Earth, Ocean and Atmospheric Science, Florida State University, Tallahassee, FL, 32306, USA.
Biodegradation. 2020 Jun;31(3):171-182. doi: 10.1007/s10532-020-09901-2. Epub 2020 May 2.
Cometabolic biodegradation of 1,4-dioxane (dioxane) in the presence of primary substrates is a promising strategy for treating dioxane at environmentally relevant concentrations. Seven aqueous amendments (i.e., tetrahydrofuran (THF), butanone, acetone, 1-butanol, 2-butanol, phenol and acetate) and five gaseous amendments (i.e., C-C alkanes and ethylene) were evaluated as the primary substrates for dioxane degradation by mixed microbial consortia. The aqueous amendments were tested in microcosm bottles and the gaseous amendments were tested in a continuous-flow membrane biofilm reactor with hollow fibers pressurized by the gaseous amendments. Ethane was found to be the most effective gaseous substrate and THF was the only aqueous substrate that promoted dioxane degradation. A diverse microbial community consisting of several putative dioxane degraders-Mycobacterium, Flavobacterium and Bradyrhizobiaceae-were enriched in the presence of ethane. This is the first study showing that ethane was the most effective substrate among the short-chain alkanes and it promoted dioxane degradation by enriching dioxane-degraders that did not harbor the well-known dioxane/tetrahydrofuran monooxygenase.
共代谢生物降解法是在存在主要基质的情况下将 1,4-二恶烷（二恶烷）生物降解的一种很有前途的策略，可用于在环境相关浓度下处理二恶烷。本研究评价了 7 种水相添加剂（即四氢呋喃（THF）、丁酮、丙酮、1-丁醇、2-丁醇、苯酚和乙酸盐）和 5 种气相添加剂（即 C-C 烷烃和乙烯）作为混合微生物群落中二恶烷降解的主要基质。水相添加剂在微宇宙瓶中进行了测试，气相添加剂在连续流动膜生物膜反应器中用气相添加剂加压的中空纤维进行了测试。发现乙烷是最有效的气态基质，THF 是唯一促进二恶烷降解的水相基质。在乙烷存在的情况下，富集了由几种假定的二恶烷降解菌（分枝杆菌、黄杆菌和慢生根瘤菌）组成的多样化微生物群落。这是首次表明乙烷是短链烷烃中最有效的基质，它通过富集不含有众所周知的二恶烷/四氢呋喃单加氧酶的二恶烷降解菌来促进二恶烷降解。
