Marine N2-fixing cyanobacteria, including the unicellular genus Crocosphaera, are considered keystone species in marine food webs. Crocosphaera are globally distributed and provide new sources of nitrogen and carbon, which fuel oligotrophic microbial communities and upper trophic levels. Despite their ecosystem importance, only one pelagic, oligotrophic, phycoerythrin-rich species, Crocosphaera watsonii, has ever been identified and characterized as widespread. Herein, we present a new species, named Crocosphaera waterburyi, enriched from the North Pacific Ocean. C. waterburyi was found to be phenotypically and genotypically distinct from C. watsonii, active in situ, distributed globally, and preferred warmer temperatures in culture and the ocean. Additionally, C. waterburyi was detectable in 150- and 4000-meter sediment export traps, had a relatively larger biovolume than C. watsonii, and appeared to aggregate in the environment and laboratory culture. Therefore, it represents an additional, previously unknown link between atmospheric CO2 and N2 gas and deep ocean carbon and nitrogen export and sequestration.

中文翻译：

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海洋 N2 固定器 Crocosphaera waterburyi


海洋固定 N2 的蓝细菌，包括单细胞属 Crocosphaera，被认为是海洋食物网中的关键物种。鳄鱼分布于全球，提供新的氮和碳来源，为寡营养微生物群落和上营养级提供燃料。尽管它们在生态系统中很重要，但只有一种中上层、寡营养、富含藻红蛋白的物种 Crocosphaera watsonii 被确定并表征为广泛分布。在这里，我们提出了一个新物种，名为 Crocosphaera waterburyi，它来自北太平洋。发现 C. waterburyi 在表型和基因型上与 C. watsonii 不同，原位活跃，分布于全球，并且喜欢在培养和海洋中温暖的温度。此外，在 150 米和 4000 米的沉积物出口陷阱中可以检测到 C. waterburyi，其生物量比 C. watsonii 大，并且似乎在环境和实验室培养中聚集。因此，它代表了大气中 CO2 和 N2 气体与深海碳和氮输出和封存之间另一个以前未知的联系。