Abstract

This study is screened for naphthalene degrading strains from a heavily polluted area with high naphthalene concentration in the rainwater for the effective removal of naphthalene from rainwater. Recently, naphthalene biodegradation has been achieved in water. However, the influences of organics and inorganics in the rainwater on the biodegradation of naphthalene remains unclear. The naphthalene degrading strain Klebsiella sp. (WJ-1) was identified from sewage sludge. The effects of temperature, pH, inoculum size, and rotation speed on the degradation ability of WJ-1 were studied. The results showed that the naphthalene degradation rates of WJ-1 in rainwater were higher than those in aqueous solution at different experimental conditions. The optimal conditions were 30 °C, 10% inoculum size, pH 7.0, and a rotation speed of 150 rpm. The substances in rainwater might be important co-metabolites of naphthalene degradation. Based on intermediate metabolites detected by gas chromatography–mass spectrometer (GC-MS), the naphthalene biodegradation pathway was identified, as being similar to the phthalic acid pathway. These results suggest WJ-1 as a good candidate for the efficient bioremediation of naphthalene from rainwater in heavily polluted areas.

摘要

本研究从雨水中萘浓度高的重度污染地区筛选萘降解菌株，以有效去除雨水中的萘。最近，已经在水中实现了萘的生物降解。但是，雨水中有机物和无机物对萘生物降解的影响尚不清楚。萘降解菌克雷伯氏菌sp。（WJ-1）是从污水污泥中鉴定出来的。研究了温度，pH，接种量和转速对WJ-1降解能力的影响。结果表明，在不同的实验条件下，雨水中WJ-1的萘降解率高于水溶液中的萘降解率。最佳条件是30°C，接种量为10％，pH 7.0，旋转速度为150 rpm。雨水中的物质可能是萘降解的重要共代谢物。根据气相色谱-质谱仪（GC-MS）检测到的中间代谢物，可以确定萘的生物降解途径，与邻苯二甲酸途径相似。这些结果表明，WJ-1是高污染地区雨水中萘高效生物修复的良好候选者。