C2/C3 fatty acid stress on anammox consortia dominated by Candidatus Jettenia asiatica

• Anammox activity decreases in response to an increasing acetate/propionate content.
• The competition from heterotrophic denitrifiers hinders the anammox activity.
• Anammox bacteria can grow at the present of low-concentration acetate/propionate.
• The growth of “Jettenia” has no superiority under acetate/propionate conditions.

Anaerobic ammonium oxidation (anammox) is a promising technology for autotrophic removal of ammonium and nitrite. In order to expand its industrial application niche, effects of organic matter need more specific investigation. In this study, the effects of C2/C3 fatty acids stress on anaerobic ammonium oxidation (anammox) process were evaluated in batch experiments. BLAST search analysis of 16S rRNA sequences showed that the homology of the highly enriched anammox consortia used here and Candidatus Jettenia asiatica (J. asiatica) reached 99%. Results showed that low acetate (⩽30 mg/L) and propionate (⩽50 mg/L) concentration does not significantly influence ammonium oxidation. Higher acetate/propionate concentrations caused decrease of ammonium removal. A level of acetate no more than 240 mg/L caused the decrease of ammonium consumption rate by 33%, and 29% for propionate with (<400 mg/L). J. asiatica showed higher adaptability to propionate stress than acetate. Real-time quantitative PCR (qPCR) results reveal that anammox bacteria J. asiatica are capable of growing at the present of low-concentration acetate (⩽120 mg/L)/propionate (⩽200 mg/L). The anammox hzo gene concentrations reached to round 0.5 × 108–1.0 × 108 copies/ml after 36 days cultivation with C2/C3 fatty acid. However, there is no superiority for J. asiatica consortia to grow under organotrophic conditions compared to autotrophic ones.