极端水质条件下异养硝化-好氧反硝化微生物的研究进展

Research progress in heterotrophic nitrifying-aerobic denitrifying bacteria under extreme water quality conditions

摘要:

在高盐、高温、低温、高氨氮、重金属等极端水质条件影响下，传统生物脱氮技术出现生物活性降低、反应速度减缓、处理效果不理想等问题，因此，开发能有效抵御极端水质环境的高效功能菌对提升生物脱氮工艺的稳定性至关重要。异养硝化-好氧反硝化菌是一种能同在单一有氧条件下进行同步异养硝化和好氧反硝化的功能微生物。研究发现部分异养硝化-好氧反硝化菌可以在极端水质条件下生长且能表现出良好脱氮性能，为传统生物脱氮技术提供了良好的菌种资源。目前已筛选出假单胞菌属(Pseudomonas)、不动杆菌属(Acinetobacter)等多种耐受极端水质条件的异养硝化-好氧反硝化菌。相关研究发现在极端水质条件胁迫下，一方面异养硝化-好氧反硝化菌与脱氮途径相关酶活性增加，进而维持其脱氮性能的稳定；另一方面该菌抗氧化酶体系活性上升，从而抵御极端水质环境。本文对高氨氮浓度、高盐、高温、低温、重金属、极端pH等极端条件下异养硝化-好氧反硝化菌的种属、脱氮效率、代谢途径和作用机理，以及工程应用现状进行综述，指出技术瓶颈，提出新的研究思路和方向，为异养硝化-好氧反硝化菌的研发和工程应用提供理论指导。

关键词:异养硝化-好氧反硝化菌;极端水质条件;生物脱氮;代谢机理

Abstract:

Under extreme water quality conditions such as high salt, high or low temperatures, high ammonia nitrogen, and heavy metals, conventional biological denitrification suffer from reduced biological activity, slowed reaction, and unsatisfactory outcomes. Therefore, the development of efficient functional bacteria capable of withstanding extreme water quality environments is crucial for enhancing the stability of biological denitrification processes. Heterotrophic nitrifying-aerobic denitrifying bacteria can remove nitrogen under completely aerobic conditions. Some of these bacteria can grow under extreme water conditions and demonstrate efficient nitrogen removal capability, offering suitable strain resources for conventional biological nitrogen removal. A variety of heterotrophic nitrifying-aerobic denitrifying bacteria such as Pseudomonas and Acinetobacter capable of tolerating extreme water quality conditions have been screened out. Under extreme water quality conditions, heterotrophic nitrifying-aerobic denitrifying bacteria increase the activities of the enzymes involved in the denitrification pathway to maintain the stability of their denitrification performance. Moreover, they increase the activities of the antioxidant enzymes to adapt to the extreme water environments. We summarize the species, denitrification efficiency, metabolic pathways, and mechanisms of heterotrophic nitrifying-aerobic denitrifying bacteria in extreme water environments characterized by high concentrations of ammonia nitrogen, elevated salinity, extreme high or low temperatures, heavy metal contamination, and extreme pH. Additionally, this paper assesses the current application status of these bacteria in engineering, identifies the technical challenges, and proposes novel research ideas for future investigations.

Key words:heterotrophic nitrifying-aerobic denitrifying bacteria;extreme water quality conditions;biological nitrogen removal;metabolic mechanism