Specific interactions have been highlighted between cyanobacteria and chemotrophic bacteria within the cyanosphere, suggesting that nutrients recycling could be optimized by cyanobacteria/bacteria exchanges. In order to determine the respective metabolic roles of the cyanobacterial and bacterial consortia (microbiome), a day–night metatranscriptomic analysis was performed on Dolichospermum sp. (N₂-fixer) and Microcystis sp. (non N₂-fixer) natural blooms occurring successively within a French peri-urban lake. The taxonomical and functional analysis of the metatranscriptoms have highlighted specific association of bacteria within the cyanosphere, driven by the cyanobacteria identity, without strongly modifying the functional composition of the microbiomes, suggesting functional redundancy within the cyanosphere. Moreover, the functional composition of these active communities was driven by the living mode. During the two successive bloom events, it appeared that NH₄⁺ (newly fixed and/or allochthonous) was preferentially transformed into amino acids for the both the microbiome and the cyanobacteria, while phosphate metabolism was enhanced, suggesting that due to a high cellular growth, P limitation might take place within the cyanosphere consortium.

中文翻译：

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洞察蓝藻：捕捉自然条件下蓝细菌和化学营养细菌的各自代谢？

蓝藻和化学营养细菌之间的特定相互作用已被强调，这表明可以通过蓝藻/细菌交换来优化养分循环。为了确定蓝藻和细菌聚生体（微生物组）各自的代谢作用，对Dolichospermum sp 进行了昼夜宏转录组学分析。(N ₂ -fixer) 和Microcystis sp。（非 N ₂-fixer）在法国城郊湖泊中连续发生的自然开花。元转录组的分类学和功能分析强调了蓝藻界内细菌的特定关联，由蓝藻身份驱动，而没有强烈改变微生物组的功能组成，表明蓝藻界内的功能冗余。此外，这些活跃社区的功能构成是由生活模式驱动的。在连续两次开花事件中，NH ₄ ⁺（新固定的和/或外源的）优先转化为微生物组和蓝细菌的氨基酸，而磷酸盐代谢增强，这表明由于细胞生长速度快，P 限制可能发生在蓝藻圈内。