División de Ciencias Ambientales, Instituto Potosino de Investigación Científica y Tecnológica (IPICyT), Camino a la Presa San José 2055, Col. Lomas 4ª. Sección, San Luis Potosí, SLP, 78216 Mexico.
J Hazard Mater. 2011 Nov 15;195:201-7. doi: 10.1016/j.jhazmat.2011.08.028. Epub 2011 Aug 16.
The anaerobic degradation of benzene coupled to the reduction of humic acids (HA) was demonstrated in two enriched consortia. Both inocula were able to oxidize benzene under strict anaerobic conditions when the humic model compound, anthraquinone-2,6-disulfonate (AQDS), was supplied as terminal electron acceptor. An enrichment culture originated from a contaminated soil was also able to oxidize benzene linked to the reduction of highly purified soil humic acids (HPSHA). In HPSHA-amended cultures, 9.3 μM of benzene were degraded, which corresponds to 279 ± 27 micro-electron equivalents (μEq)L(-1), linked to the reduction of 619 ± 81 μEq L(-1) of HPSHA. Neither anaerobic benzene oxidation nor reduction of HPSHA occurred in sterilized controls. Anaerobic benzene oxidation did not occur in soil incubations lacking HPSHA. Furthermore, negligible reduction of HPSHA occurred in the absence of benzene. The enrichment culture derived from this soil was dominated by two γ-Proteobacteria phylotypes. A benzene-degrading AQDS-reducing enrichment originated from a sediment sample showed the prevalence of different species from classes β-, δ- and γ-Proteobacteria. The present study provides clear quantitative demonstration of anaerobic degradation of benzene coupled to the reduction of HA.
在两个富集培养物中证明了与腐殖酸（HA）还原偶联的苯的厌氧降解。当提供作为末端电子受体的腐殖质模型化合物蒽醌-2,6-二磺酸盐（AQDS）时，两个接种物都能够在严格的厌氧条件下氧化苯。源自污染土壤的富集培养物也能够氧化与高度纯化的土壤腐殖酸（HPSHA）还原偶联的苯。在添加 HPSHA 的培养物中，降解了 9.3 μM 的苯，这相当于 279 ± 27 微电子当量（μEq）L（-1），与 619 ± 81 μEq L（-1）的 HPSHA 还原相关联。在灭菌对照中既没有发生厌氧苯氧化也没有发生 HPSHA 的还原。在缺乏 HPSHA 的土壤孵育中没有发生厌氧苯氧化。此外，在没有苯的情况下，HPSHA 的还原可忽略不计。源自该土壤的富集培养物主要由两个γ-变形菌的生物型组成。来自沉积物样本的具有降解苯的 AQDS 还原功能的富集培养物显示出β-、δ-和γ-变形菌纲的不同种的优势。本研究提供了明确的定量证据，证明了与 HA 还原偶联的苯的厌氧降解。
