Abstract：
In this study, the effect of external agricultural phytohormones (mixed phytohormones) addition (1.0, 5.0, 10.0, and 20.0 mg L-1) on the growth performance, lipid productivity, and sedimentation efficiency of Chlorella pyrenoidosa cultivated in saline wastewater was investigated. Among the different concentrations evaluated, the highest biomass (1.00 g L-1) and lipid productivity (11.11 mg L-1 d-1) of microalgae were obtained at 10.0 mg L-1 agricultural phytohormones addition. Moreover, exogenous agricultural phytohormones also improved the sedimentation performance of C. pyrenoidosa, which was conducive to the harvest of microalgae resources, and the improvement of sedimentation performance was positively correlated with the amount of agricultural phytohormones used. The promotion of extracellular polymeric substances synthesis by phytohormones in microalgal cells could be considered as the reason for its promotion of microalgal sedimentation. Transcriptome analysis revealed that the addition of phytohormones upregulated the expression of genes related to the mitogen-activated protein kinase (MAPK)-mediated phytohormone signaling pathway and lipid synthesis, thereby improving salinity tolerance and lipid production in C. pyrenoidosa. Overall, agricultural phytohormones provide an effective and inexpensive strategy for increasing the lipid productivity and sedimentation efficiency of microalgae cultured in saline wastewater.
摘要：
在这项研究中,外部农业植物激素（混合植物激素）添加（1.0、5.0、10.0和20.0mgL-1）对生长性能的影响，脂质生产率，研究了在含盐废水中培养的蛋白核小球藻的沉降效率。在评估的不同浓度中，添加10.0mgL-1农业植物激素时，微藻的生物量（1.00gL-1）和脂质生产率（11.11mgL-1d-1）最高。此外，外源农业植物激素也改善了蛋白核芽孢杆菌的沉降性能，这有利于微藻资源的收获，沉降性能的改善与农业植物激素用量呈正相关。微藻细胞中植物激素促进胞外聚合物合成可以认为是其促进微藻沉降的原因。转录组分析表明，植物激素的添加上调了丝裂原活化蛋白激酶（MAPK）介导的植物激素信号通路和脂质合成相关基因的表达，从而提高了蛋白核梭菌的盐度耐受性和脂质生产。总的来说,农业植物激素提供了一种有效且廉价的策略，用于提高在盐水废水中培养的微藻的脂质生产率和沉降效率。
