Chen Shi, Liu Ying, Zhang Jian, Gao Baoyu
Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Jinan, 250100, PR China.
Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Jinan, 250100, PR China.
Aquat Toxicol. 2017 Apr;185:193-200. doi: 10.1016/j.aquatox.2017.02.015. Epub 2017 Feb 20.
Research on the combined effects of antibiotic contaminants and environmental factors in cyanobacteria is still limited. This study focused on the action and its mechanism of spiramycin combined with changes in nitrogen and phosphorus level in Microcystis aeruginosa at environmentally relevant concentrations. Though photosynthetic activity was stimulated by spiramycin at a high nutrient level, no significant correlation (p>0.05) was found between photosynthesis-related proteins and growth-related proteins, and the growth rate was inhibited by 200ngL of spiramycin. At low nitrogen and low phosphorus levels, up-regulated photosynthesis-related proteins were closely correlated with (p<0.05) stress response-related, transcription-related and cell division-related proteins, which consequently led to stimulated growth of M. aeruginosa under spiramycin exposure. Spiramycin exposure also regulated the production of microcystins (MCs) and the expression of two microcystin synthetases (mcyB and mcyC). The spiramycin-induced protein secretion process and the up-regulation of ATP binding cassette transporters might contribute to the increased MC release. Enolase, superoxide dismutase, protein GrpE, DNA-directed RNA polymerase subunit alpha and serine protease were candidate target proteins of spiramycin in M. aeruginosa under different nutrient conditions. Coexisting spiramycin mitigated the threat of cyanobacteria to aquatic environments at a high nutrient level but aggravated cyanobacterial bloom at a low nitrogen level.
关于抗生素污染物与环境因素对蓝藻综合影响的研究仍然有限。本研究聚焦于在环境相关浓度下，螺旋霉素与铜绿微囊藻中氮磷水平变化的联合作用及其机制。尽管在高营养水平下螺旋霉素刺激了光合活性，但光合作用相关蛋白与生长相关蛋白之间未发现显著相关性（p>0.05），且200ng/L的螺旋霉素抑制了生长速率。在低氮和低磷水平下，上调的光合作用相关蛋白与应激反应相关、转录相关和细胞分裂相关蛋白密切相关（p<0.05），从而导致在螺旋霉素暴露下铜绿微囊藻生长受到刺激。螺旋霉素暴露还调节了微囊藻毒素（MCs）的产生以及两种微囊藻毒素合成酶（mcyB和mcyC）的表达。螺旋霉素诱导的蛋白质分泌过程和ATP结合盒转运蛋白的上调可能导致MC释放增加。烯醇化酶、超氧化物歧化酶、蛋白质GrpE、DNA指导的RNA聚合酶亚基α和丝氨酸蛋白酶是不同营养条件下螺旋霉素在铜绿微囊藻中的候选靶蛋白。共存的螺旋霉素在高营养水平下减轻了蓝藻对水生环境的威胁，但在低氮水平下加剧了蓝藻水华。
