School of Food Science and Engineering, South China University of Technology, Guangzhou 510640, China.
School of Food Science and Engineering, South China University of Technology, Guangzhou 510640, China.
Enzyme Microb Technol. 2022 Nov;161:110115. doi: 10.1016/j.enzmictec.2022.110115. Epub 2022 Aug 19.
Microalgae are considered to be a very promising class of raw material for carotenoid production. In this study, melatonin (MLT), a widely used plant growth regulator, was added to the autotrophic medium of Dunaliella bardawil to explore its effects on the growth and pigment accumulation of Dunaliella bardawil. The results showed that the induction of exogenous MLT alone was not beneficial to the growth and pigment accumulation of Dunaliella bardawil, and the higher the concentration, the more obvious the inhibitory effect on the algal cells. Therefore, a strategy to promote carotenoid accumulation in Dunaliella bardawil by combining exogenous MLT and light induction was carried out. Under 4500 LUX light intensity, the content of zeaxanthin was significantly increased under exogenous MLT induction. In the 200 μg/mL, 300 μg/mL, and 400 μg/mL MLT-treated groups, the zeaxanthin single-cell content in the 300 μg/mL-treated group was as high as 0.38 ng/mL (0.17 ng/mL in the control group), which was 1.24-fold higher compared to the control. Under 9500 LUX light intensity, all carotenoids showed an increasing trend in all experimental groups, except for zeaxanthin, which showed a decreasing trend. The effect of 300 μg/mL showed the most obvious in the 200 μg/mL,300 μg/mL, and 400 μg/mL MLT treatment groups, where the lutein, α-carotene and β-carotene contents were 1.24, 1.14 and 1.31 times higher than those of the control group, respectively. Overall, exogenous MLT at high light intensities had a significant effect on pigment accumulation in Dunaliella bardawil.
微藻被认为是生产类胡萝卜素非常有前途的一类原料。本研究在杜氏盐藻自养培养基中添加了广泛使用的植物生长调节剂褪黑素（MLT），以探讨其对杜氏盐藻生长和色素积累的影响。结果表明，单独诱导外源 MLT 对杜氏盐藻的生长和色素积累没有益处，且浓度越高，对藻细胞的抑制作用越明显。因此，采用外源 MLT 与光诱导相结合的策略来促进杜氏盐藻中类胡萝卜素的积累。在 4500 LUX 光强下，外源 MLT 诱导下叶黄素的含量显著增加。在 200μg/mL、300μg/mL 和 400μg/mL MLT 处理组中，300μg/mL 处理组的叶黄素单细胞含量高达 0.38ng/mL（对照组为 0.17ng/mL），是对照组的 1.24 倍。在 9500 LUX 光强下，除叶黄素外，所有实验组的类胡萝卜素含量均呈上升趋势。在 200μg/mL、300μg/mL 和 400μg/mL MLT 处理组中，300μg/mL 的效果最为明显，其中叶黄素、α-胡萝卜素和β-胡萝卜素的含量分别比对照组高 1.24、1.14 和 1.31 倍。总体而言，高光强下外源 MLT 对杜氏盐藻的色素积累有显著影响。
