Degradation by and toxicity to bacteria of chlorinated phenols and benzenes, and hexachlorocyclohexane isomers
Degradation by and toxicity to bacteria of chlorinated phenols and benzenes, and hexachlorocyclohexane isomers
复制标题
氯化苯酚和苯以及六氯环己烷异构体的细菌降解和毒性
DOI：
10.1007/bf00170247
复制
发表时间：
1994
影响因子：
3.6
通讯作者：
H. Viedt
中科院分区：
文献类型：
--
作者：
Elke Lang;H. Viedt
混合培养物降解氯化苯、氯化酚或六氯环己烷（HCH）作为碳和能量的唯一来源，通过富集污染土壤样品获得。代谢3-氯酚（3-CP）、2,3-二氯酚（2,3- dcp）或2,6-二氯酚（2,6- dcp）的培养物能够利用几种其他氯化化合物作为底物，而富含1,2,4,5-四氯苯（1,2,4,5- tecb）、α-HCH或γ-HCH的培养物不能代谢大多数其他氯化同属物。在30 ~ 250 μmol l−1的初始底物浓度范围内，随着底物浓度的增加，四种氯代酚类化合物的氯化物释放和生长速率均降低。在7周内氯化物的最大释放量为3.8 mg l−1，对应于35 μmol l−1三氯苯酚。相反，非酚类化合物1,2,4,5- tecb， α-HCH或γ-HCH的代谢率随着底物浓度的增加而增加。初始浓度为750 μmol l的−1α- hch或1,2,4,5- tecb在2周内完全脱氯。由于氯酚类化合物的水溶性和生物利用度远高于非酚类化合物，这表明氯酚类化合物的高生物利用度是这些底物对降解培养物具有高毒性的原因。相比之下，氯化苯和hch -异构体的低水溶性导致培养基中的浓度一直很低，高到足以诱导降解，但太低而不会损害细菌细胞。
Mixed cultures degrading chlorinated benzenes, chlorinated phenols, or hexachlorocyclohexane (HCH) as the sole source of carbon and energy were obtained by enrichment from contaminated soil samples. Cultures which metabolized 3-chlorophenol (3-CP), 2,3-dichlorophenol (2,3-DCP), or 2,6-dichlorophenol (2,6-DCP) were able to utilize several other chlorinated compounds as substrates, whereas cultures enriched with 1,2,4,5-tetrachlorobenzene (1,2,4,5-TeCB), α-HCH, or γ-HCH did not metabolize most of the other chlorinated congeners tested. Chloride release and growth rates with all four chlorinated phenols decreased with increasing initial substrate concentrations within the range of 30–250 μmol liter−1. Maximum chloride release was 3.8 mg liter−1corresponding to 35 μmol liter−1trichlorophenol within 7 weeks. In contrast, the rate of metabolism of the nonphenolic compounds 1,2,4,5-TeCB, α-HCH, or γ-HCH increased with increasing substrate concentrations. Initial concentrations of 750 μmol liter−1α-HCH or 1,2,4,5-TeCB were completely dechlorinated within 2 weeks. Because aqueous solubility and bioavailability of the chlorophenolic compounds is much higher than that of the nonphenolic compounds, it is suggested that the high bioavailability of the chlorophenolic compounds is the reason for the high toxicity of these substrates to the degrading cultures. In contrast, the low aqueous solubilities of the chlorinated benzenes and HCH-isomers caused consistently low concentrations in the medium, which were high enough to induce degradation but too low to damage the bacterial cells.