季节性低温胁迫下陇东黄土高原油污土壤环境因子对耐冷混合菌场地生态修复的响应

为了揭示季节性低温胁迫下陇东黄土高原油污土壤环境因子对耐冷混合菌场地生态修复的响应机制，利用自主筛选构建的耐冷石油降解混合菌在甘肃省庆阳市庆城县马岭镇长庆油田陇东油泥处理站开展了为期7个月的场地修复实验，采用常规方法测定了不同季节土壤理化特性、酶活性和微生物群落特性等环境指标。结果表明：（1）在季节性低温胁迫下（9-11月）M2组（耐冷混合菌处理组）月平均降解率明显增加（P<0.01），JZJ+M1组（金盏菊联合常温混合菌处理组）和M2组累计TPH降解率分别为15.37%±3.51%和28.64%±4.12%。（2）M2组土壤脱氢酶和多酚氧化酶在低温季节（LT）活性最高，且温度和处理存在显著交互作用（P<0.01）。在土壤营养元素方面，无论何种处理方式（JZJ+M1和M2）二者含量均为RT（常温季节）高于LT（P<0.05），同时明显高于CK组（P<0.05）。（3）M2组土壤微生物群落Shannon-Wiener指数和均匀度指数在LT高于RT（P<0.05）。（4）NMDS和Pearson相关性分析结果显示，M2组在低温季节具有较高TPH降解率主要与土壤多酚氧化酶、脱氢酶、单月TPH降解率（μ2）和Shannon-Wiener指数有关，且均呈极显著正相关关系。通过分析环境因子的季节响应，优化场地修复在低温环境的降解条件、加速低温期石油烃降解速率，以期为陇东地区低温耐冷混合菌场地生态修复技术的推广应用提供参考和基础数据资料。

Responses of the environmental factors to ecological remediation of crude-oil contaminated soil by using cold-tolerance oil degradation bacteria under seasonal low temperature stress in Longdong Loess Plateau

In order to further understand the environmental factor response mechanisms of crude-oil contaminated soil ecological remediation by using cold-tolerance degrading microbial agent under low temperature stress in eastern Gansu, an experiment based on the cold-tolerance degrading bacteria agent had been selected to do the ecological remediation of crude-oil contaminated soil for 7 months at Longdong oil sludge treatment station of Changqing Oilfield Company in Qingyang Prefecture of Gansu Province, and the changes and seasonal response of environmental factors to the ecological remediation in soil physicochemical properties, enzyme activity and microbial community properties were investigated using the conventional methods. The results showed that:(1) Cold-tolerance degrading microbial agent group (M2, cold-tolerance degrading microbial agent) demonstrated a higher crude oil degradation rate (28.64%±4.12%) than that of the group of room temperature degrading microbial agent combined Calendula officinalis (JZJ+M1) (15.37%±3.51%) from September to November (P<0.01). (2) The activity of soil dehydrogenase and polyphenol oxidase of M2 was the highest in the low temperature season (LT), with an obvious interaction between treatment and temperature (P<0.01). In terms of soil nutrient elements, the content of both methods (JZJ+M1 and M2) were both higher than that of LT (P<0.05) and significantly higher than that in CK group (P<0.05). (3) Index of soil microbial community Shannon-Wiener and evenness index in Group M2 also demonstrated a higher level in the cold temperature season than that in room temperature season (P<0.05). (4) Nonmetric multidimensional scaling (NMDS) analysis suggested that Group M2 in cold temperature season demonstrated a higher crude oil degradation rate, which were strongly affected by activity of soil dehydrogenase and polyphenol oxidase, Shannon-Wiener index of soil microbial community, as well as showing a positive correlation with monthly TPH degradation rate (μ2). This work was aimed to optimize and accelerate soil TPH degradation rate for ecological remediation under low temperature stress via analyzing environmental factors responses to ecological remediation of crude-oil contaminated soil, as well as to offer the basic data to application of cold-tolerance degrading microbial agent in Longdong Loess Plateau.