功能菌接种对石油污染土壤修复效果及微生物群落的影响

利用定向筛选驯化的二苯并噻吩（DBT）降解菌对石油污染土壤进行为期40 d的土壤模拟培养试验，研究了功能菌（红球菌，Rhodococcus sp. ZYL-1）接种对石油污染土壤中DBT的降解效果，结合16S rDNA高通量测序及生物信息学分析，解析了功能菌接种对土壤细菌群落演替的影响。结果表明：在25 ℃的暗箱培养过程中，红球菌添加显著提高了DBT污染土壤的降解率（P<0.001），生物接种处理组（BIOEIF）的DBT降解主要发生在培养前10 d，培养结束后DBT降解率接近60%，比依赖土壤土著微生物的自然衰减组（NAT）降解率提升10%以上；对比BIOEIF组和NAT组土壤培养过程中细菌群落组成，BIOEIF组香农多样性指数和系统发育指数显著低于NAT组，但接种红球菌未对DBT污染土壤的细菌群落组成造成显著影响，Micromonospora、Bacillus、unclassified_f_Planococcaceae为污染土壤培养过程中的优势菌属，而接种的红球菌并未成为优势菌属；网络分析表明，功能菌接种显著提升污染土壤微生物的DBT关键降解菌属类群，通过强化土壤土著微生物Shimazuella协同降解DBT，进而提升了石油烃污染土壤的修复效果，Shimazuella可能是参与DBT的代谢的关键微生物。所接种的功能菌（红球菌）可协同提高土著微生物对于石油污染土壤DBT的生物降解，具有较高的土壤修复应用潜力。

Effect of inoculation of functional bacteria on the remediation of petroleum polluted soil and the microbial community

The dibenzothiophene (DBT) degrading bacteria screened and domesticated based on previous culture experiment was inoculated into the petroleum contaminated soil for a 40 day simulated soil remediation experiment. The degradation effect of functional bacteria (Rhodococcus sp. ZYL-1) and the succession of bacterial community in the petroleum contaminated soil was analyzed. The results showed the addition of Rhodococcus sp. ZYL-1 increased significantly the degradation efficiency of DBT compared to control during the incubation at 25 ℃ in the dark chamber (P<0.001). The DBT degradation in the bioaugmentation treatment (BIOEIF) mainly occurred in the first 10 days after soil incubation, in which DBT degradation rate was close to 60% at the end of incubation, higher than that in the control, i.e., natural attenuation treatment (NAT) relying on soil indigenous microorganisms. Compared with the bacterial community composition between BIOEIF treatment and NAT treatment in the soil incubating process, the Shannon diversity index and phylogenetic diversity index of BIOEIF were significantly lower than that in NAT, but the inoculation of Rhodococcus sp. ZYL-1 did not affect significantly the composition of the soil bacterial community. Micromonospora, Bacillus, and unclassified_f_Planococcaceaeis were detected as the dominated taxa in the petroleum contaminated soil, but Rhodococcus which was inoculated did not have an obviously high abundance in soils. Network analysis showed that key functional bacteria for DBT degradation had significantly improved in the contaminated soil in BIOEIF, which might be due to the symbiosis of Shimazuella with indigenous microorganism. In conclusion, the inoculated functional bacteria (Rhodococcus sp. ZYL-1) could obviously improve the biodegradation of DBT in petroleum hydrocarbon contaminated soil based on enhancing the degradation function of indigenous microorganisms.