关键字：TRACE-ELEMENT SUPPLEMENTATION; BIOGAS PRODUCTION; DEPENDENT DENITRIFICATION; CRYSTAL-STRUCTURE; WASTE-WATER; KEY ENZYME; DIGESTION; MOLYBDENUM; ZINC; METHANOGENESIS

摘要：Metallic micronutrients play a crucial role in regulating the activity of microorganisms. Denitrifying anaerobic methane oxidation (DAMO) archaea possess all the canonical enzymes analogous to those involved in methanogenesis, which is notably rich in metalloenzymes. However, the relationship between metallic micronutrients and DAMO archaeal activity remains unexplored. Here we investigated the effect of micronutrients (Fe(II), Co (II), Ni(II), Zn(II), Se(IV), W(VI) and Mo(VI)) on the DAMO archaeal activity. Batch assays indicated that among these micronutrients, Mo(VI), W(VI) and Se(IV) had a significant impact on DAMO archaeal activity, whereas the others showed minimal effects within their respective concentration ranges. Notably, the optimal concentrations of Mo(VI), W(VI) and Se(IV) substantially boosted DAMO archaeal activity, increasing nitrate conversion rates by 2.1, 1.45, and 1.84 times, respectively, compared to the rates at their lowest concentrations. An orthogonal experiment further confirmed the significant impact of Se(IV) and identified an optimal micronutrients composition. Subsequent long-term operation of a sequencing batch reactor (SBR) with this optimized medium demonstrated substantial improvements in DAMO performance. Specially, the nitrate removal rate increased to approximately 1.5 times higher than that of the original medium, and the nitrate consumption rate reached 1.98 mmol & sdot;d- 1. In addition, microbial analysis indicated that both the abundance of Candidatus Methanoperedens and the key functional gene mcrA increased by 1.26 and 2.52 times, respectively, compared to that operated with the original medium, suggesting that the optimized medium enhanced both the metabolic activity and growth of DAMO archaea. These results underscore the pivotal role of micronutrients in modulating DAMO archaeal activity, thereby offering valuable insights for optimizing the DAMO process and advancing its practical application.

卷号：502

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