Xie Liujun, Ma Zhengxin, Yang Gairen, Huang Yuhan, Wen Tianyi, Deng Yusong, Sun Jingchao, Zheng Siyu, Wu Fangfang, Huang Kai, Shao Jinhua
Guangxi Key Laboratory of Forest Ecology and Conservation, College of Forestry, Guangxi University, Nanning 530004, China.
Guangxi Key Laboratory of Forest Ecology and Conservation, College of Forestry, Guangxi University, Nanning 530004, China.
Ecotoxicol Environ Saf. 2023 Jan 1;249:114452. doi: 10.1016/j.ecoenv.2022.114452. Epub 2022 Dec 19.
Microcystis aeruginosa is the competitively dominant algal species in eutrophic waters and poses a serious threat to the aquatic ecological environment. To investigate the effects of eucalyptus tannins (TFL) and black water in eucalyptus plantations on M. aeruginosa, this study exposed M. aeruginosa to different concentrations (0 (control), 20, 50, 80, 110, and 140 mg L) of tannic acid (TA; hydrolyzed tannins, HT; reagent tannin), epigallocatechin gallate (EGCG; condensed tannins, CT; reagent tannin), eucalyptus tannins (TFL, complex tannin) and mixed TFL + Fe solution (tannin: Fe molar ratio = 1:10). The cell density, chlorophyll-a (Chl-a) content, superoxide dismutase (SOD) activity, malondialdehyde (MDA) and soluble protein (SP) contents of algae under tannin stress were determined, and the algal cell density treated with under the combination of TFL and Fe was determined. The results showed a reduction in the Chl-a content of algal cells, which inhibited photosynthesis; leading to membrane lipid peroxidation; and the complexation of soluble proteins resulting in blocked protein synthesis were the main mechanisms by which tannins inhibited the growth of M. aeruginosa. TFL achieved the same inhibition of algal cells as the tannin reagent at the same concentration. At 4 d, TFL at 80 mg L and above could achieve more than 54.87 % algal density inhibition. The inhibition rate of 80 mg L and above TFL + Fe on algal density was more than 75 %, indicating that TFL + Fe had a stronger inhibitory effect on algal density. The results may facilitate the resource utilization of eucalyptus harvesting residues, explorations of the potential application of eucalyptus tannins in the control of M. aeruginosa, and provide new ideas for ecological algal inhibition in eucalyptus plantations.
铜绿微囊藻是富营养化水体中具有竞争优势的藻类物种，对水生生态环境构成严重威胁。为了研究桉木单宁（TFL）和桉树林地黑水对铜绿微囊藻的影响，本研究将铜绿微囊藻暴露于不同浓度（0（对照）、20、50、80、110和140 mg/L）的单宁酸（TA；水解单宁，HT；试剂单宁）、表没食子儿茶素没食子酸酯（EGCG；缩合单宁，CT；试剂单宁）、桉木单宁（TFL，复合单宁）以及混合的TFL + Fe溶液（单宁：Fe摩尔比 = 1:10）中。测定了单宁胁迫下藻类的细胞密度、叶绿素a（Chl-a）含量、超氧化物歧化酶（SOD）活性、丙二醛（MDA）和可溶性蛋白（SP）含量，并测定了TFL与Fe组合处理下的藻细胞密度。结果表明，藻细胞Chl-a含量降低，抑制了光合作用；导致膜脂过氧化；以及可溶性蛋白的络合导致蛋白质合成受阻，是单宁抑制铜绿微囊藻生长的主要机制。在相同浓度下，TFL对藻细胞的抑制作用与单宁试剂相同。在第4天，80 mg/L及以上的TFL可实现超过54.87%的藻密度抑制。80 mg/L及以上的TFL + Fe对藻密度的抑制率超过75%，表明TFL + Fe对藻密度具有更强的抑制作用。这些结果可能有助于桉木采伐剩余物的资源利用，探索桉木单宁在控制铜绿微囊藻方面的潜在应用，并为桉树林地的生态抑藻提供新思路。
