Response of Microcystis aeruginosa FACHB-905 to different nutrient ratios and changes in phosphorus chemistry

作     者：PENG Guotao Steven W.WILHELM LIN Sijie WANG Xlangrong 彭国涛;Steven W.WILHELM;林思劼;王祥荣

作者机构：College of Environmental Science and EngineeringState Key Laboratory of Pollution Control and Resource ReuseTongj UniversityShanghai 200092China Department of Environmental Science and EngineeringFudan UniversityShanghai 200433China Department of MicrobiologyUniversity of TennesseeKnoxvilleTN37920USA 

出 版 物：《Journal of Oceanology and Limnology》 (海洋湖沼学报（英文）)

年 卷 期：2018年第36卷第4期

页      面：1040-1052页

核心收录：

学科分类：0710[理学-生物学] 071001[理学-植物学] 07[理学] 

基　　金：Supported by the National Key R&D Program of China(No.2016YFC0502700) the Major Program of National Social Science Foundation of China(No.14ZDB140) the National Science Foundation(USA)(Nos.IOS1451528,DEB1240870) 

主　　题：antioxidant system chlorophyll fluorescence parameters Microcystis nutrient stress photosynthesis 

摘      要：Cyanobacterial blooms are a global problem, with their occurrence tightly tied to nutrient loading. We cultured Microcystis aeruginosa FACHB-905 in growth medium with either inorganic(orthophosphate) or organic(β-glycerophosphate or polyphosphate) phosphorus and at different N:P ratios with 50:1, 30:1, 16:1, 4:1 and 1:4, serving as the phosphorus source. Fluorescence parameters were measured to determine the response of cellular responses to nutrient stress. Scanning electron microscopy(SEM) and estimates of antioxidant activity were employed to examine potential mechanisms of physical change. The results demonstrate that inorganic phosphorus was more bioavailable to M. aeruginosa relative to organic phosphorus in culture. The highest cell concentration(2.21×10~6 cells/mL), chlorophyll-a(0.39 pg/cell) and phycocyanin(1.57 pg/cell) quotas and high levels of chlorophyll fluorescence parameters( rETR, E_k, α, φ_(PSⅡ) and F_v/F_m) were obtained when phosphorus was supplied as K_2 HPO_4 at a N:P ratio of 16–30. Organic sources of phosphorus(β-glycerophosphate and polyphosphate) were bioavailable to M. aeruginosa. In addition, too concentrated orthophosphate(N:P=1:4) resulted in the oxidative stress and lipid peroxidation of cell membrane(identified by the antioxidant system activity), and the photosynthetic activity declined consequently. This study has demonstrated the effects of different phosphorus chemistries and N:P ratios on the cyanobacterial growth, photosynthetic activity and cell physiology, which could be an effective tool for predicting cyanobacterial dominance or N-deficiency in natural lakes(due to the superior ability of cyanobacteria for dissolved N and fix atmospheric N in some cases).