PDF(Pubmed)
Abstract：
Algal biomass is a viable source of chemicals and metabolites for various energy, nutritional, medicinal and agricultural uses. While stresses have commonly been used to induce metabolite accumulation in microalgae in attempts to enhance high-value product yields, this is often very detrimental to growth. Therefore, understanding how to modify metabolism without deleterious consequences is highly beneficial. We demonstrate that low-doses (1-5 Gy) of ionizing radiation in the X-ray range induces a non-toxic, hormetic response in microalgae to promote metabolic activation. We identify specific radiation exposure parameters that give reproducible metabolic responses in Chlorella sorokiniana caused by transcriptional changes. This includes up-regulation of >30 lipid metabolism genes, such as genes encoding an acetyl-CoA carboxylase subunit, phosphatidic acid phosphatase, lysophosphatidic acid acyltransferase, and diacylglycerol acyltransferase. The outcome is an increased lipid yield in stationary phase cultures by 25% in just 24 hours, without any negative effects on cell viability or biomass.
摘要：
藻类生物质是各种能源的化学物质和代谢物的可行来源，营养,药用和农业用途。虽然胁迫通常被用来诱导微藻中的代谢物积累，试图提高高价值产品产量，这往往对增长非常不利。因此,了解如何修改新陈代谢而没有有害的后果是非常有益的。我们证明，低剂量（1-5Gy）的电离辐射在X射线范围内诱导无毒，微藻中的角化反应促进代谢活化。我们确定了特定的辐射暴露参数，这些参数可通过转录变化在小球藻中产生可重复的代谢反应。这包括>30个脂质代谢基因的上调，如编码乙酰辅酶A羧化酶亚基的基因，磷脂酸磷酸酶,溶血磷脂酸酰基转移酶，和二酰基甘油酰基转移酶。结果是在仅仅24小时内，稳定期培养物中的脂质产量增加了25％，对细胞活力或生物量没有任何负面影响。
