Abstract:
Acidimicrobium sp. strain A6 is a recently discovered autotrophic bacterium that is capable of oxidizing ammonium while reducing ferric iron and is relatively common in acidic iron-rich soils. The genome of Acidimicrobium sp. strain A6 contains sequences for several reductive dehalogenases, including a gene for a previously unreported reductive dehalogenase, rdhA. Incubations of Acidimicrobium sp. strain A6 in the presence of perfluorinated substances, such as PFOA (perfluorooctanoic acid, C8HF15O2) or PFOS (perfluorooctane sulfonic acid, C8HF17O3S), have shown that fluoride, as well as shorter carbon chain PFAAs (perfluoroalkyl acids), are being produced, and the rdhA gene is expressed during these incubations. Results from initial gene knockout experiments indicate that the enzyme associated with the rdhA gene plays a key role in the PFAS defluorination by Acidimicrobium sp. strain A6. Experiments focusing on the defluorination kinetics by Acidimicrobium sp. strain A6 show that the defluorination kinetics are proportional to the amount of ammonium oxidized. To explore potential applications for PFAS bioremediation, PFAS-contaminated biosolids were augmented with Fe(III) and Acidimicrobium sp. strain A6, resulting in PFAS degradation. Since the high demand of Fe(III) makes growing Acidimicrobium sp. strain A6 in conventional rectors challenging, and since Acidimicrobium sp. strain A6 was shown to be electrogenic, it was grown in the absence of Fe(III) in microbial electrolysis cells, where it did oxidize ammonium and degraded PFAS.
摘要:
酸性微生物。菌株A6是最近发现的自养细菌,能够氧化铵同时还原三价铁,在酸性富铁土壤中相对常见。酸性微生物的基因组。菌株A6包含几种还原性脱卤酶的序列,包括以前未报道的还原性脱卤酶的基因,rdha.酸性微生物的孵育。菌株A6在全氟化合物存在下,例如PFOA(全氟辛酸,C8HF15O2)或PFOS(全氟辛烷磺酸,C8HF17O3S),已经证明了氟化物,以及碳链较短的PFAA(全氟烷基酸),正在生产,rdhA基因在这些培养过程中表达。最初的基因敲除实验结果表明,与rdhA基因相关的酶在酸性微生物的PFAS脱氟中起关键作用。菌株A6。重点研究酸性微生物除氟动力学的实验。菌株A6表明脱氟动力学与氧化的铵的量成正比。探索PFAS生物修复的潜在应用,用Fe(III)和酸性微生物SP增强了受PFAS污染的生物固体。菌株A6,导致PFAS降解。由于对Fe(III)的高需求使酸性微生物sp。常规直肠中的A6菌株具有挑战性,并且由于酸性微生物sp。菌株A6被证明是产电的,它是在没有Fe(III)的微生物电解槽中生长的,它确实氧化了铵并降解了PFAS。