文献类型：期刊文献

英文题名：Analysis of the regulatory mechanism of exogenous IAA-mediated tryptophan accumulation and synthesis of endogenous IAA in Chlorococcum humicola

作者：Chen, Xiurong[1,2]; Ye, Xiaoyun[1,2]; Yu, Xiao[1,2]; Zhao, Jiamin[1,2]; Song, Meijing[1,2]; Yin, Danning[1,2]; Yu, Jiayu[1,2]

机构：[1] National Engineering Research Center of Industrial Wastewater Detoxication and Resource Recovery, School of Resources and Environmental Engineering, East China University of Science and Technology, Shanghai, 200237, China; [2] State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, School of Resources and Environmental Engineering, East China University of Science and Technology, Shanghai, 200237, China

年份：2024

卷号：354

外文期刊名：Chemosphere

收录：EI(收录号：20241115733460)

语种：英文

外文关键词：Acetic acid - Enzyme activity - Molecular biology - pH - Polycyclic aromatic hydrocarbons - Wastewater treatment

摘要：The activated sludge method is widely used for the treatment of phenol-containing wastewater, which gives rise to the problem of toxic residual sludge accumulation. Indole-3-acetic acid (IAA), a typical phytohormone, facilitates the microalgal resistance to toxic inhibition while promoting biomass accumulation. In this study, Chlorococcum humicola (C. humicola) was cultured in toxic sludge extract and different concentrations of IAA were used to regulate its physiological properties and enrichment of high value-added products. Ultimately, proteomics analysis was used to reveal the response mechanism of C. humicola to exogenous IAA. The results showed that the IAA concentration of 5 × 10?6 mol/L (M) was most beneficial for C. humicola to cope with the toxic stress in the sludge extract medium, to promote the activity of rubisco enzyme, to enhance the efficiency of photosynthesis, and, finally, to accumulate protein as a percentage of specific dry weight 1.57 times more than that of the control group. Exogenous IAA altered the relative abundance of various amino acids in C. humicola cells, and proteomic analyses showed that exogenous IAA stimulated the algal cells to produce more indole-3-glycerol phosphate (IGP), indole, and serine by up-regulating the enzymes. These precursors are converted to tryptophan under the regulation of tryptophan synthase (A0A383V983), and tryptophan can be metabolized to endogenous IAA to promote the growth of C. humicola. These findings have important implications for the treatment of toxic residual sludge while enriching for high-value amino acids. ? 2024 Elsevier Ltd