Table_3_The role of microbial ecology in improving the performance of anaerobic digestion of sewage sludge.DOCX

The use of next-generation diagnostic tools to optimise the anaerobic digestion of municipal sewage sludge has the potential to increase renewable natural gas recovery, improve the reuse of biosolid fertilisers and help operators expand circular economies globally. This review aims to provide perspectives on the role of microbial ecology in improving digester performance in wastewater treatment plants, highlighting that a systems biology approach is fundamental for monitoring mesophilic anaerobic sewage sludge in continuously stirred reactor tanks. We further highlight the potential applications arising from investigations into sludge ecology. The principal limitation for improvements in methane recoveries or in process stability of anaerobic digestion, especially after pre-treatment or during co-digestion, are ecological knowledge gaps related to the front-end metabolism (hydrolysis and fermentation). Operational problems such as stable biological foaming are a key problem, for which ecological markers are a suitable approach. However, no biomarkers exist yet to assist in monitoring and management of clade-specific foaming potentials along with other risks, such as pollutants and pathogens. Fundamental ecological principles apply to anaerobic digestion, which presents opportunities to predict and manipulate reactor functions. The path ahead for mapping ecological markers on process endpoints and risk factors of anaerobic digestion will involve numerical ecology, an expanding field that employs metrics derived from alpha, beta, phylogenetic, taxonomic, and functional diversity, as well as from phenotypes or life strategies derived from genetic potentials. In contrast to addressing operational issues (as noted above), which are effectively addressed by whole population or individual biomarkers, broad improvement and optimisation of function will require enhancement of hydrolysis and acidogenic processes. This will require a discovery-based approach, which will involve integrative research involving the proteome and metabolome. This will utilise, but overcome current limitations of DNA-centric approaches, and likely have broad application outside the specific field of anaerobic digestion.

采用下一代诊断工具以优化城市污泥厌氧消化过程，具有提高可再生能源天然气回收、改善生物固体肥料再利用以及助力全球循环经济扩展的潜力。本综述旨在阐述微生物生态学在提升污水处理厂消化器性能中的作用，并强调系统生物学方法对于监测连续搅拌反应器中中温厌氧污泥至关重要。此外，我们进一步强调了污泥生态学研究带来的潜在应用。提高甲烷回收率或厌氧消化工艺稳定性（尤其是预处理后或共消化过程中）的主要限制因素，与前端代谢（水解和发酵）相关的生态知识空白。诸如稳定生物泡沫等操作问题是一个关键问题，生态标志物是一种适宜的解决途径。然而，目前尚无生物标志物可用于监测和管理特定类群的泡沫潜力，以及其他风险，如污染物和病原体。基本的生态学原理适用于厌氧消化，这为预测和操控反应器功能提供了机会。在绘制厌氧消化过程中的生态标志物与工艺终点和风险因素图的过程中，未来之路将涉及数值生态学，这是一个不断发展的领域，它使用从物种丰富度、α多样性、β多样性、系统发育多样性和分类多样性以及从遗传潜力中衍生出的表型或生命策略中得出的指标。与上述通过全种群或个体生物标志物有效解决的运营问题不同，广泛提升和优化功能将需要加强水解和产酸过程。这需要一种基于发现的研究方法，涉及蛋白质组学和代谢组学的综合研究。这将利用但克服以DNA为中心的方法的当前局限性，并可能在该特定厌氧消化领域之外具有广泛的应用。