Maroneze Mariana Manzoni, Zepka Leila Queiroz, Lopes Eduardo Jacob, Pérez-Gálvez Antonio, Roca María
Department of Food Science and Technology, Federal University of Santa Maria (UFSM), 97105-900 Santa Maria, Brazil.
Food Phytochemistry Department, Instituto de la Grasa, Consejo Superior de Investigaciones Científicas (CSIC), University Campus, Building 46, Carretera de Utrera km. 1, 41013 Sevilla, Spain.
Antioxidants (Basel). 2019 Nov 29;8(12):600. doi: 10.3390/antiox8120600.
Different cultivation strategies have been developed with the aim of increasing the production rate of microalgal pigments. Specifically, biotechnological approaches are designed to increase antioxidant metabolites as chlorophyll and carotenoids. However, although significant advances have been built up, available information regarding both the chlorophyll metabolism and their oxidative reactions in photobioreactors is scarce. To unravel such processes, the detailed chlorophyll and carotenoid fraction of has been studied by HPLC-ESI/APCI-hrTOF-MS from phototrophic and heterotrophic cultures. is provided with a controlled strategy of interconversion between chlorophyll and to avoid the formation of reactive oxygen species (ROS) at high irradiances in addition to the photoacclimation of carotenoids. Indeed, precise kinetics of 13-hydroxy- and 15-hydroxy-lactone chlorophyll metabolites shows the existence of a chlorophyll oxidative metabolism as a tool to manage the excess of energy at high light conditions. Unexpectedly, the oxidation under phototrophy favored chlorophyll metabolites over the chlorophyll series, while the heterotrophic conditions exclusively induced the formation of 13-hydroxy-chlorophyll . In parallel, during the first 48 h of growth in the dark, the chlorophyll fraction maintained a promising steady state. Although future studies are required to resolve the biochemical reactions implied in the chlorophyll oxidative metabolism, the present results agree with phytoplankton metabolism.
为了提高微藻色素的生产率，人们开发了不同的培养策略。具体而言，生物技术方法旨在增加抗氧化代谢产物，如叶绿素和类胡萝卜素。然而，尽管已经取得了显著进展，但关于光生物反应器中叶绿素代谢及其氧化反应的现有信息却很匮乏。为了阐明这些过程，我们通过HPLC-ESI/APCI-hrTOF-MS对光合和异养培养物中的叶绿素和类胡萝卜素详细组分进行了研究。除了类胡萝卜素的光适应外，还提供了一种叶绿素a和叶绿素b之间相互转换的可控策略，以避免在高辐照度下形成活性氧（ROS）。事实上，13-羟基和15-羟基内酯叶绿素代谢物的精确动力学表明，存在一种叶绿素氧化代谢，作为在高光条件下管理过剩能量的一种手段。出乎意料的是，光合条件下的氧化作用有利于叶绿素b代谢物而非叶绿素a系列，而异养条件则专门诱导13-羟基叶绿素a的形成。同时，在黑暗中生长的前48小时内，叶绿素组分保持了一个有前景的稳定状态。尽管需要未来的研究来解析叶绿素氧化代谢中隐含的生化反应，但目前的结果与浮游植物代谢一致。
