Tetracyclines lead to ammonium accumulation during nitrification process

Evaluating acute toxicity in enriched nitrifying cultures: Lessons learned

“…In nitrification inhibition studies, the enriched consortium is preferred over pure AOB/NOB isolates to better represent microbial diversity; further, they are easier to maintain (Li et al 2016). Some authors employed samples with high nitrification activity directly from WWTPs (Li et al 2020a;Velasco-Garduño et al 2020), and others, more commonly, use nitrifying biomass enriched in lab-scale reactors under specific growth conditions seeded with activated sludge (Huang et al 2016;Langbehn et al 2020).…”

“…Moreover, nitrifying bacteria in these enrichments coexist with other microorganisms (i.e., heterotrophs), and their presence can interfere with the metabolic activity of nitrifiers. In some cases, lab-scale enrichment promotes the growth of AOB/NOB populations in the complete absence of organic substrates (Langbehn et al 2020;Huang et al 2016), while others enhance the fraction of nitrifiers under low C/N to sustain the heterotrophs in the culture (Katiglopu-Yazan et al 2017). Other factors, e.g., flocs and cell aggregates, influence the distribution of nitrifiers in the inoculum (Manser et al, 2005;Fang et al, 2009;Wang et al 2012), affecting the mass transfer of substrates and oxygen.…”