Department of Chemical and Biochemical Engineering, Technical University of Denmark, Risoe Campus, Building 330, P.O.B. 49, Frederiksborgvej 399, DK-4000 Roskilde, Denmark.
Plant Physiol Biochem. 2012 Dec;61:71-9. doi: 10.1016/j.plaphy.2012.09.007. Epub 2012 Oct 2.
Triacylglycerols, an energy storage compound in microalgae, are known to be accumulated after nitrogen starvation of microalgae cells. Microalgae could be of importance for future biodiesel production due to their fast growth rate and high oil content. In collections of temperature sensitive mutants of Chlamydomonas reinhardtii and Chlorella vulgaris, nine out of fourty-one mutants in C. reinhardtii and eleven out of fifty-three mutants in C. vulgaris contained increased amounts of neutral lipids, predominantly as triacylglycerols. Upon temperature induced cell-cycle arrest, these mutants showed enlarged cellular volume compared with the wild type. The C. reinhardtii mutants were analyzed further and one type of mutants displayed a shift in lipid composition from polar membrane lipids to neutral lipids after a temperature up-shift, while the second type of mutants accumulated more total lipid per cell, predominantly as neutral lipids as compared with the wild type. Three C. reinhardtii mutants were analyzed further and found to be arrested after DNA synthesis but prior to cell division in the cell cycle. These mutants will be useful in order to further understand neutral lipid accumulation in microalgae and suggest possibilities for biodiesel production by specific induction of lipid accumulation in miroalgal cultures by cell-cycle inhibition.
三酰基甘油是微藻中一种储能化合物，已知在微藻细胞氮饥饿后会积累。由于微藻生长迅速且油含量高，因此它们可能对未来的生物柴油生产具有重要意义。在莱茵衣藻和普通小球藻的温度敏感突变体集合中，41 个莱茵衣藻突变体中有 9 个和 53 个普通小球藻突变体中有 11 个突变体中性脂质含量增加，主要为三酰基甘油。在温度诱导的细胞周期停滞时，这些突变体与野生型相比细胞体积增大。进一步分析莱茵衣藻突变体，一种类型的突变体在温度上升后显示出从极性膜脂到中性脂的脂质组成的转变，而第二种类型的突变体与野生型相比，每细胞积累更多的总脂质，主要为中性脂质。进一步分析了三个莱茵衣藻突变体，发现它们在细胞周期中 DNA 合成后但在细胞分裂前被阻止。这些突变体将有助于进一步了解微藻中中性脂质的积累，并通过细胞周期抑制特异性诱导微藻培养物中脂质积累，为生物柴油生产提供可能性。
