Departamento de Bioquímica y Biología Molecular, Campus de Excelencia Internacional Agroalimentario CeiA3, Universidad de Córdoba, Córdoba, Spain.
Microbiol Spectr. 2022 Aug 31;10(4):e0018722. doi: 10.1128/spectrum.00187-22. Epub 2022 Jul 19.
Marine , together with , contribute to a significant proportion of the primary production on Earth. The spatial distribution of these two groups of marine picocyanobacteria depends on different factors such as nutrient availability and temperature. Some ecotypes thrive in mesotrophic and moderately oligotrophic waters, where they exploit both oxidized and reduced forms of nitrogen. Here, we present a comprehensive study, which includes transcriptomic and proteomic analyses of the response of sp. strain WH7803 to nanomolar concentrations of nitrate, compared to micromolar ammonium or nitrogen starvation. We found that has a specific response to a nanomolar nitrate concentration that differs from the response shown under nitrogen starvation or the presence of standard concentrations of either ammonium or nitrate. This fact suggests that the particular response to the uptake of nanomolar concentrations of nitrate could be an evolutionary advantage for marine against in the natural environment. Marine are a very abundant group of photosynthetic organisms on our planet. Previous studies have shown blooms of these organisms when nanomolar concentrations of nitrate become available. We have assessed the effect of nanomolar nitrate concentrations by studying the transcriptome and proteome of sp. WH7803, together with some physiological parameters. We found evidence that sp. strain WH7803 does sense and react to nanomolar concentrations of nitrate, suggesting the occurrence of specific adaptive mechanisms to allow their utilization. Thus, very low concentrations of nitrate in the ocean seem to be a significant nitrogen source for marine picocyanobacteria.
海洋微生物与真核浮游藻类共同构成了地球上初级生产力的重要组成部分。这两组海洋微微型蓝藻的空间分布取决于不同的因素，如营养物质的可利用性和温度。一些生态型在中营养和中度贫营养水域中茁壮成长，在这些水域中，它们同时利用氧化和还原形式的氮。在这里，我们进行了一项全面的研究，包括对 sp. 菌株 WH7803 转录组和蛋白质组的分析，以了解其对纳米摩尔浓度硝酸盐的反应，与微米摩尔铵或氮饥饿相比。我们发现，与氮饥饿或存在标准浓度的铵或硝酸盐相比， sp. 对纳米摩尔浓度硝酸盐有特定的反应。这一事实表明，对纳米摩尔浓度硝酸盐吸收的特殊反应可能是海洋微生物相对于真核浮游藻类在自然环境中的一个进化优势。海洋微生物是我们星球上非常丰富的光合生物群体。先前的研究表明，当纳米摩尔浓度的硝酸盐可用时，这些生物会大量繁殖。我们通过研究 sp. WH7803 的转录组和蛋白质组以及一些生理参数来评估纳米摩尔硝酸盐浓度的影响。我们发现证据表明， sp. 菌株 WH7803 确实能够感知和对纳米摩尔浓度的硝酸盐做出反应，这表明存在特定的适应机制来允许其利用。因此，海洋中非常低浓度的硝酸盐似乎是海洋微微型蓝藻的重要氮源。
