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 165 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 bacterial. 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 x 10(8)-1.0 x 10(8) copies/ml after 36 days cultivation with C2/C3 fatty acid. However, there is no superiority for). asiatica consortia to grow under organotrophic conditions compared to autotrophic ones. (C) 2014 Elsevier B.V. All rights reserved.