Ontañon Ornella M, González Paola S, Agostini Elizabeth
Departamento de Biología Molecular, FCEFQyN, Universidad Nacional de Río Cuarto, Ruta 36 Km 601. CP 5800, Río Cuarto, Córdoba, Argentina,
Environ Sci Pollut Res Int. 2015 Sep;22(17):13014-23. doi: 10.1007/s11356-015-4571-y. Epub 2015 Apr 29.
Bioremediation has emerged as an environmental friendly strategy to deal with environmental pollution. Since the majority of polluted sites contain complex mixtures of inorganic and organic pollutants, it is important to find bacterial strains that can cope with multiple contaminants. In this work, a bacterial strain isolated from tannery sediments was identified as Acinetobacter guillouiae SFC 500-1A. This strain was able to simultaneously remove high phenol and Cr(VI) concentrations, and the mechanisms involved in such process were evaluated. The phenol biodegradation was catalized by a phenol-induced catechol 1,2-dioxygenase through an ortho-cleavage pathway. Also, NADH-dependent chromate reductase activity was measured in the cytosolic fraction. The ability of this strain to reduce Cr(VI) to Cr(III) was corroborated by detection of Cr(III) in cellular biomass after the removal process. While phenol did not affect significantly the chromate reductase activity, Cr(VI) was a major disruptor of catechol dioxygenase activity. Nevertheless, this activity was high even in presence of high Cr(VI) concentrations. Our results suggest the potential application of A. guillouiae SFC 500-1A for wastewaters treatment, and the obtained data provide the insights into the removal mechanisms, dynamics, and possible limitations of the bioremediation.
生物修复已成为一种处理环境污染的环保策略。由于大多数污染场地含有无机和有机污染物的复杂混合物，因此找到能够应对多种污染物的细菌菌株非常重要。在这项工作中，从制革厂沉积物中分离出的一株细菌被鉴定为吉氏不动杆菌SFC 500-1A。该菌株能够同时去除高浓度的苯酚和六价铬，并对该过程涉及的机制进行了评估。苯酚的生物降解由苯酚诱导的邻苯二酚1,2-双加氧酶通过邻位裂解途径催化。此外，在胞质部分中检测到了依赖NADH的铬酸盐还原酶活性。在去除过程后，通过检测细胞生物质中的三价铬，证实了该菌株将六价铬还原为三价铬的能力。虽然苯酚对铬酸盐还原酶活性没有显著影响，但六价铬是儿茶酚双加氧酶活性的主要干扰物。然而，即使在高浓度六价铬存在的情况下，该活性仍然很高。我们的结果表明吉氏不动杆菌SFC 500-1A在废水处理中的潜在应用，并且所获得的数据为生物修复的去除机制、动力学和可能的局限性提供了见解。
