矿物油污染土壤中芳烃组分的生物降解与微生物生长动态

以石油污染土壤中分离的细菌和真菌为供试微生物,研究不同微生物组合对矿物油芳烃组分降解及降解率与微生物生长间的关系.将不同组合的微生物接种到加有柴油浓度为1 000mg/L的液体培养基中,25～30℃经摇床连续培养100d.于0～60h内连续取样,进行微生物生长动态检测;于5～100d定期取样,研究微生物生长状况与矿物油降解率动态变化.同时,以草甸棕壤(0～20cm)制备的土壤悬浮液为土壤微生物对照,以灭菌培养基为非生物降解对照.结果表明,试验前期(约20d)外源菌的降解效果优于土壤微生物,试验中、后期,土壤微生物降解优势增大且保持持续.试验结束时,土壤微生物处理的液体培养基中芳烃降解率最高达79.24%,显著高于其它3组处理.

Biodegradation of Aromatic Hydrocarbons and Dynamics of Microbe Growth in Soils Contaminated with Mineral Oil

Some bacteria and fungi selected from brown soil contaminated with petroleum were taken as test microbes. Degradation of mineral oil, by different combinations of microbes and the correlation between the degradation rate and microbial growth were studied. The bacteria and fungi were inoculated to a liquid substrate spiked with 1000 milligrams diesel-oil per liter. The temperature of rocking-bed was controlled at 25 to 30 centigrade and the experiment continued for 100 days. From 0 to 60 hours it was sampled continuously to monitor the dynamic of microbial growth, and sampled termly from 5 to 100 days to study the growth of microbes and the dynamic of degradation rate. At the same time, the suspension of 0 to 20 centimeters of topsoil of the meadow umber was taken as soil microbial control, and the culture without microbes as blank control. Results showed that degradation effect of the introduced microbes were superior to that of the indigenous microbes in short term (about 20 days), while the advantage of indigenous microbes got stronger and stronger, and the predominance maintained until the experiment was stopped. At the end of the experiment the degradation rate in the treatment of indigenous microbes reached 79.24%, which was above the results of other 3 treatments, and the difference was significant.