Engineering Lab for Water Pollution Control and Resources Recovery of Jilin Province, School of Environment, Northeast Normal University, Changchun 130117, Jilin, China.
Engineering Lab for Water Pollution Control and Resources Recovery of Jilin Province, School of Environment, Northeast Normal University, Changchun 130117, Jilin, China.
Water Res. 2022 Jun 30;218:118524. doi: 10.1016/j.watres.2022.118524. Epub 2022 Apr 30.
Coupling the cultivation of microalgae with wastewater treatment is a promising technology to recover bioresources from wastewater. However, toxic pollutants in wastewater seriously inhibit the growth of microalgae and the removal of pollutants. Phenolic acids are similar to phytohormones, could potentially relieve the toxicity to microalgae and simultaneously promote pollutant degradation and lipid accumulation. Chlorella and 4-chlorophenol (4-CP) were utilized to simulate the toxic wastewater treatment, and the roles of two typical phenolic acids, such as p-hydroxybenzoic acid (p-HBA) and caffeic acid (CA), were explored. The 0.2 μM concentration of p-HBA or CA improved the specific growth rate by 7.6% by enhancing photosynthesis and DNA replication. The oxidative damage caused by 4-CP was reduced by 30.3-49.7% via the synthesis of more antioxidant enzymes and the direct scavenging of free radicals by phenolic acids. Furthermore, the 4-CP removal rate increased by 27.0%, and toxic 4-CP was degraded into non-toxic compounds. The phenolic acids did not change the 4-CP degradation pathway but accelerated its removal and detoxification by enhancing the expression of 4-CP degradation enzymes. Simultaneously, lipid production increased by 20.5-23.1% due to the upregulation of enzymes related to fatty acid and triacylglycerol synthesis. Trace phenolic acids stimulated the mitogen-activated protein kinase signaling cascade and the calcium signaling pathway to regulate the physiology of the microalgae and protect cells from toxic stress. This study provides a promising new strategy for toxic wastewater treatment and bioresource recovery.
将微藻培养与废水处理相结合是从废水中回收生物资源的一种很有前途的技术。然而，废水中的有毒污染物严重抑制了微藻的生长和污染物的去除。酚酸类似于植物激素，可能缓解微藻的毒性，同时促进污染物降解和脂质积累。利用小球藻和 4-氯苯酚（4-CP）模拟有毒废水处理，探索了两种典型酚酸，如对羟基苯甲酸（p-HBA）和咖啡酸（CA）的作用。0.2 μM 浓度的 p-HBA 或 CA 通过增强光合作用和 DNA 复制，将比生长速率提高了 7.6%。酚酸通过合成更多的抗氧化酶和直接清除自由基，将 4-CP 引起的氧化损伤降低了 30.3-49.7%。此外，4-CP 的去除率提高了 27.0%，有毒的 4-CP 被降解成无毒的化合物。酚酸并没有改变 4-CP 的降解途径，而是通过增强 4-CP 降解酶的表达来加速其去除和解毒。同时，由于与脂肪酸和三酰基甘油合成相关的酶的上调，脂质产量增加了 20.5-23.1%。痕量酚酸刺激丝裂原活化蛋白激酶信号级联和钙信号通路，调节微藻的生理学并保护细胞免受毒性应激。本研究为有毒废水处理和生物资源回收提供了一种很有前途的新策略。
