title: Influence of cetyltrimethyl ammonium bromide on nutrient uptake and cell responses of Chlorella vulgaris.
abstract: The removal of nutrients by algae is regarded as a vital process in wastewater treatment, however algal cell activity can be inhibited by some toxic chemicals during the biological process. This study investigated the uptake of ammonia nitrogen (NH₄⁺) and total phosphorus (TP) by a green alga (Chlorella vulgaris) and algal cell responses under the stress of cetyltrimethyl ammonium bromide (CTAB), a representative for quaternary ammonium compounds (QACs, cationic surfactants). When the concentration of CTAB increased from 0 to 0.6 mg/L, the uptake efficiencies of NH₄⁺ and TP decreased from 88% to 18% and from 96% to 15%, respectively. Algal cell responses showed a decline in photosynthesis activity as indicated by the increase of chlorophyll autofluorescence from 2.9 a.u. to 25.3 a.u.; and a decrease of cell viability from 88% to 51%; and also a drop in esterase activity as indicated by the decrease in fluorescence of fluorescein diacetate stained cells from 71.5 a.u. to 4.7 a.u. Additionally, a transcription and translation response was confirmed by an enhancement of PO peak and amide II peak in algal cellular macromolecular composition stimulated by CTAB. The results suggest that QACs in wastewater may inhibit nutrient uptake by algae significantly through declining algal cell activities.
authors.affiliation: Department of Environmental Science and Engineering, Xiangtan University, Xiangtan 411105, PR China. liangzhijie1987@126.com
authors.forename: Zhijie
authors.initials: Z
authors.lastname: Liang
authors.forename: Fei
authors.initials: F
authors.lastname: Ge
authors.forename: Hui
authors.initials: H
authors.lastname: Zeng
authors.forename: Yin
authors.initials: Y
authors.lastname: Xu
authors.forename: Fang
authors.initials: F
authors.lastname: Peng
authors.forename: Minghung
authors.initials: M
authors.lastname: Wong
mesh_terms: D000704:Analysis of Variance; D001692:Biological Transport / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D000077286:Cetrimonium; D002593:Cetrimonium Compounds / Q000633:toxicity*; D048408:Chlorella vulgaris / Q000187:drug effects* / Q000378:metabolism* / Q000502:physiology; D002734:Chlorophyll / Q000378:metabolism; D004950:Esterases / Q000378:metabolism; D005453:Fluorescence; D010758:Phosphorus / Q000493:pharmacokinetics; D010788:Photosynthesis / Q000187:drug effects / Q000502:physiology; D000644:Quaternary Ammonium Compounds / Q000493:pharmacokinetics; D014865:Waste Disposal, Fluid / Q000379:methods*; D018508:Water Purification / Q000379:methods*
chemical_list: D002593:Cetrimonium Compounds; D000644:Quaternary Ammonium Compounds; D002734:Chlorophyll; D010758:Phosphorus; D004950:Esterases; D000077286:Cetrimonium