摘要
探究了两种纳米银(AgNPs)即由支链聚乙烯亚胺修饰的带正电荷的纳米银(BPEI-AgNPs)和由柠檬酸盐修饰的带负电荷的纳米银(Citrate-AgNPs)对铜绿微囊藻(M.aeruginosa)的生物毒性,以揭示AgNPs对铜绿微囊藻生物毒性的电荷依赖性.结果表明:与带正电荷的纳米银BPEI-AgNPs相比,带负电荷的Citrate-AgNPs对铜绿微囊藻的生长和光合活性具有更强的抑制作用.0.5mg/L Citrate-AgNP组的丙二醛(MDA)含量峰值(100.8nmol/mgprot))高于同浓度BPEI-AgNP组(82.5nmol/mgprot).与BPEI-AgNPs相比,相同浓度的Citrate-AgNPs作用下,铜绿微囊藻的sod2基因和GPX基因的表达分别显著上调和下调,导致藻细胞中过氧化水平显著地升高.同时,与Citrate-AgNPs相比,BPEI-AgNPs显著促进藻细胞外聚合物(EPS)的分泌,0.5mg/L BPEI-AgNP组达到32.21mg/gSS(16d),EPS的包覆作用有效地抵抗了BPEI-AgNPs的毒性.0.5mg/L Citrate-AgNP组最终胞内Ag+离子释放量是0.5mg/L BPEI-AgNP组的2.13倍,藻细胞严重破裂.因此,Ag+离子的激增导致Citrate-AgNPs对细胞的剧烈损伤.此外,Citrate-AgNPs显著抑制了光合作用(rbcS和rbcL)和能量代谢(por)基因的表达.
The behavior and biotoxic effects of two silver nanoparticles(AgNPs)modified by polyethyleneimine(BPEI-AgNPs with positive charge)and citric acid(Citrate-AgNPs with negative charge)on Microcystis aeruginosa(M.aeruginosa)were investigated to evaluate the surface charge–dependent biotoxicity of AgNPs on M.aeruginosa.A more pronounced suppressive influence on the growth and photosynthetic activity of M.aeruginosa was observed with the Citrate-AgNPs than with the BPEI-AgNPs.The peak content of malondialdehyde(MDA)in 0.5mg/L Citrate-AgNP group(100.8nmol/mgprot)was higher than that in the same concentration BPEI-AgNP group(82.5nmol/mgprot).Compared with BPEI-AgNPs,Citrate-AgNPs demonstrated a significant up-and down-regulation on sod2 and GPX gene expression in M.aeruginosa,resulting in a higher peroxidation in algal cells.The extracellular polymer(EPS)secretion was observed with BPEI-AgNPs,amounting up to 32.21mg/gSS in 0.5mg/L BPEI-AgNP group(16d).Subsequently,the toxicity of BPEI-AgNPs was neutralized by the coating effect of EPS.The final intracellular Ag+released in the 0.5mg/L Citrate-AgNP group was 2.13 times that of the 0.5mg/L BPEI-AgNP group,and M.aeruginosa cells were seriously ruptured.Therefore,the surge of Ag+ions triggered severe cellular impairment to cells by Citrate-AgNPs.Furthermore,Citrate-AgNPs significantly inhibited the expression of photosynthesis(rbcS and rbcL)and energy metabolism(por)genes.
作者
雍玲丽
陈猷鹏
郭劲松
方芳
孙壮壮
晏鹏
YONG Ling-li;CHEN You-peng;GUO Jin-song;FANG Fang;SUN Zhuang-zhuang;YAN Peng(College of Environment and Ecology,Chongqing University,Chongqing 400045,China)
出处
《中国环境科学》
EI
CAS
CSCD
北大核心
2024年第1期510-519,共10页
China Environmental Science
基金
国家重点研发计划项目(20119YFD1100200)
重庆英才计划“包干制”项目(cstc2022ycjh-bgzxm0129)
重庆市自然科学基金面上项目(CSTB2022NSCQ-MSX0964)。
关键词
纳米银
表面电荷
铜绿微囊藻
生物毒性
转录组学
silver nanoparticles
surface charges
Microcystis aeruginosa
biotoxicity
transcriptomics
