The many emerging applications of microalgae such as Chlorella also instigate interest in their ability to conduct protein modifications such as N-glycosylation. Chlorella vulgaris has recently been shown to equip its proteins with highly O-methylated oligomannosidic N-glycans. Two other frequently occurring species names are Chlorella sorokiniana and Chlorella pyrenoidosa—even though the latter is taxonomically ill defined. We analyzed by mass spectrometry and nuclear magnetic resonance spectroscopy the N-glycans of type culture collection strains of C. sorokiniana and of a commercial product labeled C. pyrenoidosa. Both samples contained arabinose, which has hitherto not been found in N-glycans. Apart from this only commonality, the structures differed fundamentally from each other and from that of N-glycans of land plants. Despite these differences, the two algae lines exhibited considerable homology in their ITS1-5.8S-ITS2 rDNA sequences. These drastic differences of N-glycan structures between species belonging to the very same genus provoke questions as to the biological function on a unicellular organism.

中文翻译：

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Chlorella sorokiniana 和相关菌株的 N-聚糖含有阿拉伯糖，但结构截然不同。

微藻（如小球藻）的许多新兴应用也引起了人们对其进行蛋白质修饰（如 N-糖基化）能力的兴趣。小球藻最近已经显示出装备其蛋白质与高度O- -甲基oligomannosidic ñ -glycans。另外两个经常出现的物种名称是Chlorella sorokiniana和Chlorella pyrenoidosa——尽管后者在分类学上定义不明确。我们通过质谱和核磁共振波谱分析了C. sorokiniana和标记为C. pyrenoidosa的商业产品的典型培养物保藏菌株的N-聚糖. 两个样品都含有阿拉伯糖，迄今为止在N-聚糖中未发现这种物质。除了这唯一的共同点之外，这些结构彼此之间以及与陆生植物的N-聚糖的结构存在根本不同。尽管存在这些差异，但两个藻类品系在其 ITS1-5.8S-ITS2 rDNA 序列中表现出相当大的同源性。属于同一属的物种之间N-聚糖结构的这些巨大差异引发了关于单细胞生物的生物学功能的问题。