Evaluation of Microbial Population Dynamics in Anaerobic Digesters during Stable Operation, Reactor Failure and Performance Recovery

厌氧消化池稳定运行、反应器故障和性能恢复期间微生物种群动态评估

• 批准号: RGPIN-2016-05929
• 负责人: Cicek, Nazim
• 金额: $ 3.06万
• 依托单位: University of Manitoba
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=647739
• 关键词: Evaluation; Microbial; Population; Dynamics; Anaerobic

The co-utilization of agricultural and industrial waste streams as feedstock for anaerobic bioreactor systems has emerged as a promising technology for value-added product synthesis. Conversion of animal manures and waste streams originating from food processing and biofuel production industries to commercially important bio-products (such as biogas) serves multiple goals of environmental reclamation, renewable fuel production, greenhouse gas mitigation, and economic development. Anaerobic co-digestion of agricultural and industrial wastes is a growing industry in Canada with potential for significant expansion. One of the enduring challenges of anaerobic digesters is system stability in the face of varying feedstock quality to ensure reliable energy supplies and uninterrupted operations. Process instability can be caused by toxic, organic, or hydraulic overload. Factors leading to toxic overload include accidental spillage of toxic compounds (antimicrobial disinfectants, antibiotics) into the influent, while variable feed consistency, excessive solids content or insufficient retention time can lead to organic overload. Consequently, digesters are usually not operated at their maximum design capacity in order to avoid collapse of gas production. A better understanding of the complex processes involved in anaerobic digestion is needed to improve process stability, monitoring and overall efficiency.***The main goal of the proposed research program is to identify groups within the microbial community of an anaerobic digester that can serve as an early warning indicator of impending failure under a variety of overload conditions. Ultimately, these groups can then be targeted during routine analysis of digesters, and a management strategy can be developed to circumvent failure and maintain steady operation. In order to determine if there are such identifiable indicator groups, a series of failure prediction tests will be conducted in continuous-feed anaerobic digesters, where process failure will be induced while the evolution of the microbial community is monitored. Organic overload will be brought on by adding three different types of co-digestion substrates to dairy manure digesters: waste glycerol, waste fatty acids (both by-products of an industrial biodiesel facility), and waste silage. Toxic shocks will be induced by introducing chemical compounds commonly used on dairy-farm operations: copper sulfate (antibacterial solution used for foot-baths) and oxytetracycline (a common veterinary antibiotic). Changing microbial groups will be identified and the significance of the changing population evaluated with a cutting-edge metagenomic approach. The use of high-throughput Illumina sequencing will allow for comprehensive coverage and characterization of the microbial community while providing access to organisms with a low relative abundance.**

利用农业和工业废水作为厌氧生物反应器系统的原料已经成为一种有前途的增值产品合成技术。将来自食品加工和生物燃料生产行业的动物粪便和废物流转化为具有重要商业意义的生物产品（如沼气），有助于实现环境回收、可再生燃料生产、减少温室气体排放和经济发展的多重目标。在加拿大，农业和工业废物的厌氧共消化是一个不断发展的行业，具有显著扩张的潜力。厌氧消化器面临的长期挑战之一是在不同原料质量下系统的稳定性，以确保可靠的能源供应和不间断的运行。过程不稳定可由有毒、有机或液压过载引起。导致有毒超载的因素包括有毒化合物（抗菌消毒剂、抗生素）意外泄漏到进水中，而饲料浓度变化、固体含量过高或滞留时间不足可能导致有机超载。因此，为了避免气体生产的崩溃，消化器通常不会以其最大设计容量运行。需要更好地了解厌氧消化的复杂过程，以提高过程的稳定性、监测和整体效率。***提出的研究计划的主要目标是确定厌氧消化器微生物群落中的群体，这些群体可以作为各种过载条件下即将发生故障的早期预警指标。最终，在对消化器进行常规分析时，可以针对这些群体，并制定管理策略以避免故障并保持稳定运行。为了确定是否存在这样可识别的指标组，将在连续进料厌氧消化池中进行一系列故障预测试验，在监测微生物群落演变的同时诱导工艺故障。在奶牛粪便消化池中添加三种不同类型的共消化基质会导致有机超载：废甘油、废脂肪酸（都是工业生物柴油设施的副产品）和废青贮饲料。中毒性休克将通过引入在奶牛场操作中常用的化合物引起：硫酸铜（用于足浴的抗菌溶液）和土霉素（一种常见的兽医抗生素）。变化的微生物组将被确定和变化的人口的意义评估与尖端的宏基因组方法。使用高通量Illumina测序将允许全面覆盖和表征微生物群落，同时提供相对丰度较低的生物体