Anaerobic phenol biodegradation: kinetic study and microbial community shifts under high concentrations dynamic loading

In this study, we provide an extended kinetic study of phenol biodegradation realized in an anaerobic sequencing batch reactor (SBR) operated with a microbial consortium. The process was investigated both in co-metabolic and metabolic conditions, and glucose has been employed as co-substrate in metabolic tests. After the acclimatization phase, the co-metabolic process was investigated at increasing phenol load (up to 2000 mg/L influent concentration), then the glucose was progressively decreased until metabolic conditions where reached and the phenol was fed at the same concentration level. Kinetic models were applied for all the operating conditions and related parameters were evaluated and compared for metabolic and co-metabolic conditions and with previous literature data. The microbial community was characterised through 16S NGS and PICRUSt2 at the different operating conditions to determine 1) the structure and composition of the microbial community developed within the reactor, 2) the effect of the reactor operation on the driving microbial species and 3) the potential functionality of the community in the degradation of phenol at each phase.

本研究针对以微生物群落（microbial consortium）运行的厌氧序批式反应器（anaerobic sequencing batch reactor，SBR）内的苯酚生物降解过程，开展了扩展动力学研究。本研究分别在共代谢与代谢条件下对该过程进行探究，并在代谢实验中以葡萄糖作为共基质（co-substrate）。驯化阶段结束后，先在苯酚进水浓度逐步提升（最高达2000 mg/L）的条件下开展共代谢过程研究，随后逐步降低葡萄糖投加量直至达到代谢条件，并以相同浓度投加苯酚。针对所有运行工况应用动力学模型，对代谢与共代谢条件下的相关参数进行评估，并与已有文献数据开展对比分析。针对不同运行工况，通过16S下一代测序（16S Next-Generation Sequencing，16S NGS）与PICRUSt2对微生物群落进行表征，以明确以下三点：1）反应器内形成的微生物群落的结构与组成；2）反应器运行模式对优势菌种的影响；3）各阶段群落在苯酚降解过程中的潜在功能。