Chen Hao-Hong, Jiang Jian-Guo
College of Food Science and Engineering, South China University of Technology , Guangzhou, Guangdong 510640, People's Republic of China.
J Agric Food Chem. 2017 Sep 20;65(37):8099-8110. doi: 10.1021/acs.jafc.7b03495. Epub 2017 Sep 11.
Microalgae lipids have attracted great attention in the world as a result of their potential use for biodiesel productions. Microalgae are cultivated in photoautotrophic conditions in most cases, but several species are able to grow under heterotrophic conditions, in which microalgae are cultivated in the dark where the cell growth and reproduction are supported by organic carbons. This perspective is covering the related studies concerning the difference between hetero- and autotrophic cultivation of microalgae. The auto- and heterotrophic central carbon metabolic pathways in microalgae are described, and the catalyzing reactions of several key metabolic enzymes and their corresponding changes in the protein level are summarized. Under adverse environmental conditions, such as nutrient deprivation, microalgae have the ability to highly store energy by forming triacylglycerol (TAG), the reason for which is analyzed. In addition, the biosynthesis of fatty acids and TAGs and their difference between auto- and heterotrophic conditions are compared at the molecular level. The positive regulatory enzymes, such as glucose transporter protein, fructose-1,6-bisphosphate aldolase, and glycerol-3-phosphate dehydrogenase, and the negative regulation enzymes, such as triose phosphate isomerase, played a crucial role in the lipid accumulation auto- and heterotrophic conditions.
微藻脂质因其在生物柴油生产中的潜在用途而在全球引起了极大关注。在大多数情况下，微藻是在光合自养条件下培养的，但有几种微藻能够在异养条件下生长，即在黑暗中培养微藻，细胞的生长和繁殖由有机碳提供支持。本文综述了有关微藻异养和自养培养差异的相关研究。描述了微藻的自养和异养中心碳代谢途径，总结了几种关键代谢酶的催化反应及其在蛋白质水平上的相应变化。在诸如营养缺乏等不利环境条件下，微藻具有通过形成三酰甘油（TAG）来高度储存能量的能力，并分析了其原因。此外，在分子水平上比较了脂肪酸和TAG的生物合成及其在自养和异养条件下的差异。葡萄糖转运蛋白、果糖-1,6-二磷酸醛缩酶和甘油-3-磷酸脱氢酶等正向调节酶以及磷酸丙糖异构酶等负向调节酶在脂质积累的自养和异养条件中起着关键作用。
