Ibarrolaza Agustín, Coppotelli Bibiana M, Del Panno María T, Donati Edgardo R, Morelli Irma S
Centro de Investigación y Desarrollo en Fermentaciones Industriales, CINDEFI (UNLP, CCT-La Plata, CONICET), La Plata, Buenos Aires, Argentina.
Biodegradation. 2009 Feb;20(1):95-107. doi: 10.1007/s10532-008-9203-5. Epub 2008 Jul 5.
The combined effect of phenanthrene and Cr(VI) on soil microbial activity, community composition and on the efficiency of bioremediation processes has been studied. Biometer flask systems and soil microcosm systems contaminated with 2,000 mg of phenanthrene per kg of dry soil and different Cr(VI) concentrations were investigated. Temperature, soil moisture and oxygen availability were controlled to support bioremediation. Cr(VI) inhibited the phenanthrene mineralization (CO(2) production) and cultivable PAH degrading bacteria at levels of 500-2,600 mg kg(-1). In the bioremediation experiments in soil microcosms the degradation of phenanthrene, the dehydrogenase activity and the increase in PAH degrading bacteria counts were retarded by the presence of Cr(VI) at all studied concentrations (25, 50 and 100 mg kg(-1)). These negative effects did not show a correlation with Cr(VI) concentration. Whereas the presence of Cr(VI) had a negative effect on the phenanthrene elimination rate, co-contamination with phenanthrene reduced the residual Cr(VI) concentration in the water exchangeable Cr(VI) fraction (WEF) in comparison with the soil microcosm contaminated only with Cr(VI). Clear differences were found between the denaturing gradient gel electrophoresis (DGGE) patterns of each soil microcosm, showing that the presence of different Cr(VI) concentrations did modulate the community response to phenanthrene and caused perdurable changes in the structure of the microbial soil community.
研究了菲和六价铬对土壤微生物活性、群落组成以及生物修复过程效率的联合影响。对每千克干土中含有2000毫克菲和不同六价铬浓度的生物测定瓶系统和土壤微观系统进行了研究。控制温度、土壤湿度和氧气供应以支持生物修复。六价铬在500 - 2600毫克/千克的水平下抑制了菲的矿化（二氧化碳产生）和可培养的多环芳烃降解细菌。在土壤微观系统的生物修复实验中，在所有研究浓度（25、50和100毫克/千克）下，六价铬的存在均延缓了菲的降解、脱氢酶活性以及多环芳烃降解细菌数量的增加。这些负面影响与六价铬浓度没有相关性。虽然六价铬的存在对菲的去除率有负面影响，但与仅受六价铬污染的土壤微观系统相比，菲的共同污染降低了水可交换六价铬部分（WEF）中的残留六价铬浓度。在每个土壤微观系统的变性梯度凝胶电泳（DGGE）图谱之间发现了明显差异，表示不同六价铬浓度的存在确实调节了群落对菲的反应，并导致微生物土壤群落结构发生持久变化。
