Cleveland Catie S, Turk-Kubo Kendra A, Zhao Yiming, Zehr Jonathan P, Webb Eric A
Marine and Environmental Biology, University of Southern California, 3616 Trousdale Pkwy, Los Angeles, CA, 90089, United States.
Ocean Sciences Department, University of California, Santa Cruz, 1156 High St., Santa Cruz, CA, 95064, United States.
ISME J. 2024 Jan 8;18(1). doi: 10.1093/ismejo/wrae217.
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.
包括单细胞属蓝球藻属在内的海洋固氮蓝细菌被认为是海洋食物网中的关键物种。蓝球藻属分布于全球，提供新的氮源和碳源，为贫营养微生物群落和较高营养级提供养分。尽管它们在生态系统中具有重要意义，但迄今为止，仅有一种浮游、贫营养、富含藻红蛋白的物种——沃森蓝球藻被鉴定并表征为广泛分布。在此，我们介绍一种从北太平洋富集的新物种，命名为沃特伯里蓝球藻。研究发现，沃特伯里蓝球藻在表型和基因型上与沃森蓝球藻不同，在原位具有活性，全球分布，在培养和海洋环境中偏好较高温度。此外，在150米和4000米的沉积物输出陷阱中可检测到沃特伯里蓝球藻，其生物体积比沃森蓝球藻相对更大，并且在环境和实验室培养中似乎会聚集。因此，它代表了大气二氧化碳和氮气与深海碳氮输出及封存之间另一个此前未知的联系。
