石油污染土壤生物修复对土壤酶活性的影响

Effect of Soil Enzyme Activities During Bioremediation of Crude Oil-Contaminated Soil

土壤酶活性是土壤微生物生物化学过程的综合反映。为了探究石油污染土壤生物修复过程中土壤酶活性变化规律研究,采用筛选和分离的3株对石油烃有良好降解效果的降解菌构建了混合菌体系,开展了石油污染土壤模拟生物修复实验,考察了不同修复时期土壤石油烃残留量、石油烃表观降解率以及四种土壤酶(脲酶、过氧化氢酶、脱氢酶、脂肪酶)活性的变化。结果表明,石油污染土壤经40d生物修复后,石油烃表观降解率达到64.4%。在石油污染土壤的生物修复过程中,脲酶活性在0～24d上升较快,24d后趋于稳定;过氧化氢酶和脱氢酶活性的变化规律相似,均在前期上升随后略有下降;脂肪酶活性有一个快速上升阶段(0～16d),而后又出现明显的下降。进一步统计分析表明,脲酶与石油烃残留量呈显著负相关性(r=-0.916,P<0.05);过氧化氢酶和脱氢酶活性与石油烃残留量呈极显著负相关性,相关系数分别为-0.974(P<0.01)和-0.969(P<0.01);而脂肪酶活性与石油烃残留量的相关性不显著(P>0.05)。

Soil enzyme activity comprehensively reflects the soil microorganism biochemical process. In order to explore the changes of soil enzyme activities during bioremediation of crude oil-contaminated soil,constructed crude oil degrading bacterial consortium were built withthree strains isolated from oil-contaminated soil, bioremediation experiments of crude oil-contaminated soil were conducted, and the change of total petroleum hydrocarbon（TPH）, apparent degradation efficiencies and soil enzyme activities（urease, catalase, dehydrogenase and lipase） were examined during the crude oil-contaminated soil bioremediation. The results showed that the apparent degradation efficiency of crude oil reached 64.4% after 40 d of bioremediation. Urease activity rapidly increased during 0-24 d, then tended to be stable.The catalase activity and dehydrogenase activity increased in early stage then slightly declined. However, lipase activity had a rapid rise phase（0-16 d）, then obviously slowed down. The results of statistical analysis showed that soil urease activity and TPH had significant negative relationship（-0.916, P〈0.05）. Catalase and dehydrogenase activities were both significantly correlated with soil TPH concentration, and their correlation coefficients were -0.974（P〈0.01） and -0.969（P〈0.01）, respectively. However, soil lipase activity did not have significant correlationship with TPH（P〉0.05）. Therefore, soil enzyme activities are potential valuable indicators of oil biodegradation.