1. Novel insights into self-defense function of anammox sludge under magnesium ions (Mg2+) stress based on Mg2+ transport system.
- Author
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Wang, Pengcheng, Lu, Bin, and Chai, Xiaoli
- Subjects
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TRANSPORT theory , *MAGNESIUM ions , *ANAEROBIC bacteria , *NITROGEN analysis , *SELF-defense - Abstract
[Display omitted] • 0.8 mmol/L Mg2+ significantly enhances the performance of anammox systems. • Mg2+ strengthens genetic repair to improve the anti-shock capacity of AnAOB. • Mg2+ transport theory was introduced to reveal the response of AnAOB to Mg2+. • A self-defense function of AnAOB based on PhoQ/PhoP-MgtAB system was proposed. Magnesium ion (Mg2+) plays an important role in the accumulation and stability of anaerobic ammonium-oxidizing bacteria (AnAOB). In this study, the response of anammox sludge to Mg2+ was comprehensively investigated by performance evaluation and metagenomics analysis. Appropriate Mg2+ (0.8 mmol/L) could improve the nitrogen removal performance, AnAOB activity, and the synthesis potential of some hydrophobic substances, while high Mg2+ (>1.6 mmol/L) has a negative effect. Meanwhile, Mg2+ transmembrane transport theory was introduced to reveal the response principle of AnAOB to Mg2+ from a novel insight. AnAOB may have a self-defense function based on the PhoQ/PhoP-MgtAB system. Low extracellular Mg2+ will activate this function to enhance Mg2+ influx, thereby improving the intracellular metabolism of AnAOB. Excessive Mg2+, however, dormant this function and induces Mg2+ efflux, which may decrease the intracellular Mg2+ and thus affect AnAOB metabolism. These findings provide valuable references for the Mg2+ regulation of anammox-based process. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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