title: Effects of high ammonium level on biomass accumulation of common duckweed Lemna minor L.
abstract: Growing common duckweed Lemna minor L. in diluted livestock wastewater is an alternative option for pollutants removal and consequently the accumulated duckweed biomass can be used for bioenergy production. However, the biomass accumulation can be inhibited by high level of ammonium (NH4 (+)) in non-diluted livestock wastewater and the mechanism of ammonium inhibition is not fully understood. In this study, the effect of high concentration of NH4 (+) on L. minor biomass accumulation was investigated using NH4 (+) as sole source of nitrogen (N). NH4 (+)-induced toxicity symptoms were observed when L. minor was exposed to high concentrations of ammonium nitrogen (NH4 (+)-N) after a 7-day cultivation. L. minor exposed to the NH4 (+)-N concentration of 840 mg l(-1) exhibited reduced relative growth rate, contents of carbon (C) and photosynthetic pigments, and C/N ratio. Ammonium irons were inhibitory to the synthesis of photosynthetic pigments and caused C/N imbalance in L. minor. These symptoms could further cause premature senescence of the fronds, and restrain their reproduction, growth and biomass accumulation. L. minor could grow at NH4 (+)-N concentrations of 7-84 mg l(-1) and the optimal NH4 (+)-N concentration was 28 mg l(-1).
authors: Biogas Institute of Ministry of Agriculture, Chengdu, 610041, China, wangwenguo@caas.cn.
authors: Wenguo
authors: W
authors: Wang
authors: Chuang
authors: C
authors: Yang
authors: Xiaoyu
authors: X
authors: Tang
authors: Xinjiao
authors: X
authors: Gu
authors: Qili
authors: Q
authors: Zhu
authors: Ke
authors: K
authors: Pan
authors: Qichun
authors: Q
authors: Hu
authors: Danwei
authors: D
authors: Ma
mesh_terms: D064751:Ammonium Compounds / Q000032:analysis / Q000302:isolation & purification / Q000633:toxicity*; D029064:Araceae / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D056804:Biofuels; D018533:Biomass; D002244:Carbon / Q000378:metabolism; D009584:Nitrogen / Q000378:metabolism; D010788:Photosynthesis / Q000187:drug effects; D014865:Waste Disposal, Fluid / Q000379:methods*; D062065:Wastewater / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000302:isolation & purification / Q000633:toxicity*
chemical_list: D064751:Ammonium Compounds; D056804:Biofuels; D002244:Carbon; D009584:Nitrogen; D062065:Wastewater; D014874:Water Pollutants, Chemical