紫茉莉修复石油污染盐碱土壤过程中的微生物群落响应

以石油污染盐碱土壤为研究对象,利用磷脂脂肪酸(PLFAs)活性微生物标记法,分析紫茉莉(Mirabilis jalapa Linn.)根际土壤微生物群落结构的动态变化,探讨紫茉莉生长对根际土壤微生物与石油烃（TPH）降解的影响。结果表明,供试土壤中,先后出现了24种微生物PLFAs,包括标识细菌的饱和脂肪酸（ SAT）、标识革兰氏阳性菌（G+）的末端支链型饱和脂肪酸（TBSAT）、标识革兰氏阴性菌（G-）的单不饱和脂肪酸（MONO）和环丙脂肪酸（CYCLO）、标识真菌的多不饱和脂肪酸(PUFA)和标识放线菌的中间型支链型饱和脂肪酸（MBSAT）等六大类型。与未种紫茉莉土壤（CK）相比,根际土壤微生物 PLFAs种类变异率在春、夏、秋季分别为71.4%、69.2%和33.3%;TPH降解率在春、夏、秋季分别提高了47.6%、28.3%、18.9%。相关性分析表明,石油烃的降解在 CK土壤中与77.8%的 PLFAs具有正相关关系(r＞0),55.6%的种类具有高度正相关性(r≥0.8),其中,与 SAT和MONO类群的相对含量正相关,相关系数分别为0.92、0.60;根际土壤中仅与42.1%的 PLFAs正相关,21.1%的种类高度正相关,与 TBSAT、MONO和 CYCLO类群的相对含量正相关,相关系数分别为0.56、0.50、0.07。说明紫茉莉生长对根际土壤微生物群落结构及 TPH降解速率均具有较大影响,且随生长季节的不同而有很大差异。

Effect of Mirabilis jalapa (Linn.) Growth on Microbial Community in Bioremediation of Petroleum-contaminated Saline-alkali Soil

Microbial biomass and species in the rhizosphere soil of Mirabilis jalapa (Linn.) (the saline-alkali soil contaminated by total petroleum hydrocarbon (TPH)) were studied with the technology of phospholipid fatty acids (PLFAs) analysis, to ex-plore the effects of Mirabilis jalapa (Linn.) growth on the structure characteristics of microbial communities and degradation of TPH in the petroleum-contaminated saline-alkali soil. The result showed that compared with the CK soil without Mirabilis jalapa (Linn.), the kind change rates of PLFAs were 71.4%, 69.2% and 33.3% in spring, summer and autumn, respectively, and the degradation of TPH increased by 47.6%, 28.3%, and 18.9% in the rhizosphere soil in spring, summer and autumn, respec-tively. Correlation analysis was used to determine the correlation between the degradation of TPH and the soil microbial communities: 77.8% of the microbial PLFAs showed positive correlation (the correlation coefficient r﹥0) with the degra-dation of TPH, and 55.6% of the PLFAs had high positive correlation with the degradation of TPH with a correlation coefficient r≥0.8. In addition, the relative contents of SAT and MONO had high correlation with the degradation of TPH in the CK soil, and the correlation coefficients were 0.92 and 0.60, respectively; but in the rhizosphere soil, 42.1% of the PLFAs had positive correlation with it, and only 21.1% had high positive correlation with the degradation of TPH, the relative con-tents of TBSAT, MONO and CYCLO had moderate or low positive correlation with the degradation of TPH, and the correlation coefficients were 0.56, 0.50 and 0.07 respectively. It was shown that the growth of mirabilis jalapa (Linn.) highly affected the microbial community structure and TPH degradation speed in the rhizosphere soil, providing a theoretical basis for the research on phytoremediation of petroleum-contaminated saline-alkali soil.