Patel Anil K, Huang Eric L, Low-Décarie Etienne, Lefsrud Mark G
†Department of Bioresource Engineering, McGill University, Ste. Anne de Bellevue, Quebec H9X 3V9, Canada.
‡School of Biological Sciences, University of Essex, Colchester CO4 3SQ, United Kingdom.
J Proteome Res. 2015 Aug 7;14(8):3051-67. doi: 10.1021/pr501316h. Epub 2015 Jul 8.
Chlamydomonas reinhardtii was batch-cultured for 12 days under continuous illumination to investigate nitrogen uptake and metabolic responses to wastewater processing. Our approach compared two conditions: (1) artificial wastewater containing nitrate and ammonia and (2) nutrient-sufficient control containing nitrate as sole form of nitrogen. Treatments did not differ in final biomass; however, comparison of group proteomes revealed significant differences. Label-free shotgun proteomic analysis identified 2358 proteins, of which 92 were significantly differentially abundant. Wastewater cells showed higher relative abundances of photosynthetic antenna proteins, enzymes related to carbon fixation, and biosynthesis of amino acids and secondary metabolites. Control cells showed higher abundances of enzymes and proteins related to nitrogen metabolism and assimilation, synthesis and utilization of starch, amino acid recycling, evidence of oxidative stress, and little lipid biosynthesis. This study of the eukaryotic microalgal proteome response to nitrogen source, availability, and switching highlights tightly controlled pathways essential to the maintenance of culture health and productivity in concert with light absorption and carbon assimilation. Enriched pathways in artificial wastewater, notably, photosynthetic carbon fixation and biosynthesis of plant hormones, and those in nitrate only control, most notably, nitrogen, amino acid, and starch metabolism, represent potential targets for genetic improvement requiring targeted elucidation.
莱茵衣藻在持续光照下进行分批培养12天，以研究其对废水处理的氮吸收和代谢反应。我们的方法比较了两种条件：（1）含硝酸盐和氨的人工废水，以及（2）以硝酸盐作为唯一氮源的营养充足对照。处理组的最终生物量没有差异；然而，对蛋白质组的比较显示出显著差异。无标记鸟枪法蛋白质组分析鉴定出2358种蛋白质，其中92种蛋白质的丰度存在显著差异。处理废水的细胞中光合天线蛋白、与碳固定相关的酶以及氨基酸和次生代谢物生物合成的相对丰度较高。对照细胞中与氮代谢和同化、淀粉的合成与利用、氨基酸循环、氧化应激证据相关的酶和蛋白质丰度较高，且脂质生物合成较少。这项关于真核微藻蛋白质组对氮源、可用性和转换的反应的研究突出了与光吸收和碳同化协同维持培养物健康和生产力所必需的严格控制的途径。人工废水中富集的途径，特别是光合碳固定和植物激素生物合成，以及仅含硝酸盐对照中的途径，最显著的是氮、氨基酸和淀粉代谢，代表了需要有针对性阐明的遗传改良潜在靶点。
