萘厌氧降解菌群的富集及氧化还原介体的强化

为揭示氧化还原介体（ROMs）对萘厌氧降解的强化作用，以萘为唯一碳源富集到中温萘厌氧降解菌群.通过Illumina MiSeq测序对接种污泥和富集培养物进行了细菌群落结构解析，并考察了固定化蒽醌-2，6-二磺酸（AQDS）、蒽醌-2-磺酸（AQS）和腐殖酸强化萘厌氧降解的特征.Illumina MiSeq测序结果表明，Pseudomonas、Thauera、和Georgfuchsia是该富集培养物中的优势萘降解菌，其相对丰度分别为52.4%、13.8%和17.6%.在污泥接种量为0.23g/L和萘初始浓度10mg/L条件下，富集菌群9d内对萘的降解率约为64%.ROMs强化试验结果表明，3种ROMs对萘的厌氧降解均有一定的促进作用.其中，AQDS的强化效果最为显著，当AQDS浓度为0.8mmol/L，培养至第7d时，萘的去除率为92.0%，比同期的对照组高1.2倍.此外，硝酸盐对ROMs强化萘厌氧降解的影响研究结果表明，在NaNO₃浓度为0~0.8g/L范围内，萘的降解速率随着硝酸盐浓度增加呈现先增加后降低的趋势.当NaNO₃浓度为0.6g/L时，萘的去除率在第6d就达到了91.0%，比对照组提高了15.2%.由此可见，在厌氧条件下添加适量硝酸盐可提高ROMs对萘降解的强化效果.

Enrichment of naphthalene anaerobic degrading bacterial consortium and enhancement by redox mediators

To reveal the catalytic effect of redox mediators (ROMs) on naphthalene anaerobic degradation, a mesophilic naphthalene anaerobic degrading bacterial consortium was enriched using naphthalene as sole carbon source. The bacterial community structure of inoculated sludge and enriched consortium were analyzed by Illumina MiSeq. The catalytic effect of anthraquinone-2,6-disulfonate (AQDS), anthraquinone-2-sulfonate (AQS) and humic acid on naphthalene degradation was also investigated. Illumina MiSeq sequencing revealed that Pseudomonas, Thauera, and Georgfuchsia were the dominant genera in the enriched consortium. Their relative abundance was 52.4%, 13.8% and 17.6%, respectively. Under the inoculated sludge of 0.23g/L and initial naphthalene of 10mg/L conditions, the naphthalene removal was 64.0% within 9 days by the enriched consortium. The result of enhancement experiment showed that ROMs could enhance the anaerobic degradation of naphthalene. Among them, the enhancement effect of AQDS was higher than other ROMs. At the AQDS of 0.8mmol/L, naphthalene removal reached 92.0% on the 7^th day, which was higher than that of the control by1.2times. In addition, this study also investigated the effect of nitrate on the degradation of naphthalene. The results showed that the naphthalene removal showed a decreasing trend after increasing with nitrate increase from 0.2 to 0.8g/L. When the concentration of NaNO₃ was 0.6g/L, the naphthalene removal reached 91.0% on the 6^th day, which is higher than control by 15.2%. Therefore, appropriate nitrate would enhance the catalytic effect of ROMs on naphthalene degradation.