摘要
为了探究有机物共存下重金属镉(Cd^(2+))对铜绿微囊藻(Microcysis aeruginosa)生长的影响,进而为水环境重金属污染治理提供理论依据,研究以1.05×10^(6)个/mL铜绿微囊藻为受试生物,0~0.20 mg/L Cd^(2+)为目标污染物,10 mg/L L-色氨酸和腐殖酸钠为有机物代表,通过12 d培养试验,分析有机物共存条件下Cd^(2+)对铜绿微囊藻细胞密度、叶绿素a质量浓度、丙二醛浓度、过氧化氢酶和超氧化物歧化酶活性生理指标的影响。结果显示,Cd^(2+)对铜绿微囊藻生长存在胁迫作用,在0.01 mg/L、0.05 mg/L、0.10 mg/L质量浓度时,随着Cd^(2+)质量浓度的升高,胁迫作用逐渐增强,表现为藻细胞密度降低,叶绿素a质量浓度下降,丙二醛浓度升高,过氧化氢酶、超氧化物歧化酶活性上升;当Cd^(2+)质量浓度达到0.20 mg/L时,铜绿微囊藻开始出现死亡,各生理指标随培养时间增加而减弱;当Cd^(2+)质量浓度为0.01 mg/L、0.05 mg/L、0.10 mg/L时,L-色氨酸和腐殖酸钠均可减轻Cd^(2+)对铜绿微囊藻的胁迫作用,且腐殖酸钠的缓解作用强于L-色氨酸;当Cd^(2+)质量浓度为0.20 mg/L时,L-色氨酸的缓解作用不明显,腐殖酸钠对Cd^(2+)的胁迫仍具有较好的缓解作用。三维荧光光谱分析显示,Cd^(2+)对L-色氨酸和腐殖酸钠均有荧光猝灭作用,且对腐殖酸钠猝灭程度强于L-色氨酸。
To investigate the combined effects of cadmium(Cd^(2+))and organic matter on algae,a 12-day cultivation experiment was conducted using Microcystis aeruginosa(initial density:1.05×10^(6) cells/mL).The algae were exposed to five Cd^(2+)concentrations(0,0.01 mg/L,0.05 mg/L,0.10 mg/L,and 0.20 mg/L)in the presence of either 10 mg/L L-tryptophan or sodium humate.Physiological parameters,including cell density,chlorophyll-a concentration,Malondialdehyde(MDA)levels,and the activities of Catalase(CAT)and Superoxide Dismutase(SOD),were systematically analyzed.The results revealed that the addition of either L tryptophan or sodium humate at 10 mg/L increased the cell density of Microcystis aeruginosa in the absence of Cd^(2+)in the culture system.When Cd^(2+)acted as a stressor,inhibiting the growth of Microcystis aeruginosa at concentrations of 0.01 mg/L,0.05 mg/L,and 0.10 mg/L,the inhibitory effect intensified with increasing Cd^(2+)concentration.This was reflected by a decrease in cell density,a reduction in chlorophyll-a content,an increase in MDA concentration,and elevated activities of CAT and SOD.Furthermore,the addition of either L tryptophan or sodium humate at this concentration was found to alleviate the stress effects of Cd^(2+)on Microcystis aeruginosa.Both the algal cell inhibition rate and the 12-day EC50 fitting curve indicated that sodium humate provided a stronger protective effect than L tryptophan.When the Cd^(2+)concentration reached 0.20 mg/L,cell death in Microcystis aeruginosa was observed.As the culture progressed,all physiological indicators showed a decline.L tryptophan did not alleviate the stress effects of Cd^(2+),while sodium humate continued to demonstrate a strong alleviating effect on the stress caused by Cd^(2+).Three-dimensional fluorescence spectroscopy revealed that Cd^(2+)induced fluorescence quenching in both L tryptophan and sodium humate.Regional integral calculations showed that the fluorescence area integral volume of L-tryptophan decreased by 10.74%,while that of sodium humate decreased by 19.04%.This indicates that Cd^(2+)caused a stronger fluorescence quenching effect in sodium humate compared to L−tryptophan.
作者
申慧彦
张宇
徐华健
李卫华
王翔翔
SHEN Huiyan;ZHANG Yu;XU Huajian;LI Weihua;WANG Xiangxiang(School of Environment and Energy Engineering,Anhui Jianzhu University,Hefei 230601,China;Anhui Provincial Key Laboratory of Environmental Pollution Control and Resource Reuse,Hefei 230601,China)
出处
《安全与环境学报》
北大核心
2025年第12期4923-4932,共10页
Journal of Safety and Environment
基金
国家自然科学基金项目(52370021)
安徽省教育厅创新团队项目(2022AH010019)
安徽省教育厅高校自然科学研究项目(2024AH050249)
安徽省科技创新平台重大科技项目(202305a12020039)。
关键词
环境工程学
镉
溶解性有机质
铜绿微囊藻
胁迫作用
荧光光谱
environmental engineering
cadmium
dissolved organic matter
Microcystis aeruginosa
stress effect
fluorescence spectroscopy
