Xie Zhangzhang, Wu Zhiyu, Wang Oumei, Liu Fanghua
National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Institute of Eco-environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou 510650, PR China.
National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Institute of Eco-environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou 510650, PR China; Laboratory for Marine Biology and Biotechnology, Laoshan Laboratory, Qingdao 266237, PR China.
J Hazard Mater. 2023 Jun 15;452:131216. doi: 10.1016/j.jhazmat.2023.131216. Epub 2023 Mar 15.
The ecotoxicological effects of herbicide contamination on the autotrophic growth of microalgae in aquatic environments have been major concerns. However, little is known about the influence of herbicides on the mixotrophic growth of microalgae. This study investigated the ecotoxicological effect of 3-(3,4-dichlorophenyl)-1,1-dimethyl-urea (DCMU) on the mixotrophic growth of Chlorella sacchrarophila FACHB 4. Results showed that C. sacchrarophila in mixotrophy was more resistant to DCMU than in photoautotrophy. Moreover, a low content of DCMU (20-80 μg·L) promoted the mixotrophic growth of C. sacchrarophila, and the promotion effect was obviously enhanced with the increase in light intensity. The chlorophyll content and glucose absorption rate of C. sacchrarophila were found to increase after incubation with DCMU for 24 h. Transcriptome analyses revealed that the mechanism of DCMU to promote the mixotrophic growth of C. sacchrarophila was probably through accelerating glucose uptake and utilization, which was accomplished by reducing photodamage and increasing the chlorophyll content of C. sacchrarophila. This study not only revealed an unexpected bloom of mixotrophic microalgae triggered by herbicides, but it also shed new light on an effective and low-cost strategy to improve the microalgae productivity for utilization.
除草剂污染对水生环境中微藻自养生长的生态毒理学影响一直是人们主要关注的问题。然而，关于除草剂对微藻混合营养生长的影响却知之甚少。本研究调查了3-(3,4-二氯苯基)-1,1-二甲基脲（DCMU）对嗜糖小球藻FACHB 4混合营养生长的生态毒理学效应。结果表明，混合营养型的嗜糖小球藻对DCMU的抗性比光合自养型更强。此外，低含量的DCMU（20 - 80μg·L）促进了嗜糖小球藻的混合营养生长，且随着光照强度的增加，促进作用明显增强。发现嗜糖小球藻在与DCMU孵育24小时后，叶绿素含量和葡萄糖吸收率增加。转录组分析表明，DCMU促进嗜糖小球藻混合营养生长的机制可能是通过加速葡萄糖的摄取和利用，这是通过减少光损伤和增加嗜糖小球藻的叶绿素含量来实现的。本研究不仅揭示了除草剂引发的混合营养型微藻意外大量繁殖的现象，还为提高微藻利用效率的有效且低成本策略提供了新的思路。
