ABSTRACT The application of plant growth regulators is a new strategy for industrial cultivation of microalgae to enhance growth performance and synthesis of bio-products. In this study, changes in some growth indices, biochemical content, and fatty acid (FA) profile of Isochrysis galbana were investigated in response to 2, 4-dichlorophenoxyacetic acid (2, 4-D) at 0, 1, 2, 4 and 6 mg l−1. Based on the results, 2 mg l−1 2, 4-D significantly improved biomass, growth rate, and doubling time; however, 6 mg l−1 2, 4-D inhibited growth. Maximum chlorophyll a was observed at 2 mg l−1 2, 4-D. The highest crude protein content was calculated in 2 mg l−1 2, 4-D. Lipid accumulation was significantly increased at 1 and 2 mg l−1 2, 4-D compared to the control group (P < 0.05). The highest and lowest concentrations of polyunsaturated FAs were observed in 6 mg l−1 (47.32% of total FAs) and 1 mg l−1 (35.72% of total FAs), respectively. However, maximum levels of saturated and monounsaturated FAs were obtained at 1 mg l−1. Overall, the current study showed that addition of 2, 4-D at 2 mg l−1 can improve both growth performance and lipid accumulation in I. galbana.

中文翻译：

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2, 4-二氯苯氧乙酸能否改变海洋微藻等鞭金藻的生长性能、生化成分和脂肪酸谱？

摘要 植物生长调节剂的应用是微藻工业化栽培以提高生长性能和生物产品合成的一种新策略。在本研究中，研究了等鞭金藻在 0、1、2、4 和 2, 4-二氯苯氧乙酸 (2, 4-D) 下的某些生长指数、生化含量和脂肪酸 (FA) 谱的变化。 6 毫克 l−1。根据结果​​，2 mg l−1 2, 4-D 显着提高了生物量、生长速度和倍增时间；然而，6 mg l-1 2, 4-D 抑制了生长。在 2 mg l-1 2, 4-D 观察到最大叶绿素 a。最高粗蛋白含量以 2 mg l-1 2, 4-D 计算。与对照组相比，1 和 2 mg l-1 2, 4-D 的脂质积累显着增加（P < 0.05）。分别在 6 mg l-1（总 FAs 的 47.32%）和 1 mg l-1（总 FAs 的 35.72%）中观察到最高和最低浓度的多不饱和 FAs。然而，饱和和单不饱和脂肪酸的最大水平在 1 mg l-1 时获得。总体而言，目前的研究表明，添加 2 mg l-1 的 2, 4-D 可以改善 I. galbana 的生长性能和脂质积累。