College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, China.
Frontiers Science Center for Deep Ocean Multispheres and Earth System, Ocean University of China, Qingdao, 266003, China.
Commun Biol. 2022 Jul 14;5(1):705. doi: 10.1038/s42003-022-03631-2.
Members of the marine Roseobacter group are ubiquitous in global oceans, but their cold-adaptive strategies have barely been studied. Here, as represented by Loktanella salsilacus strains enriched in polar regions, we firstly characterized the metabolic features of a cold-adapted Roseobacter by multi-omics, enzyme activities, and carbon utilization procedures. Unlike in most cold-adapted microorganisms, the TCA cycle is enhanced by accumulating more enzyme molecules, whereas genes for thiosulfate oxidation, sulfate reduction, nitrate reduction, and urea metabolism are all expressed at lower abundance when L. salsilacus was growing at 5 °C in comparison with higher temperatures. Moreover, a carbon-source competition experiment has evidenced the preferential use of glucose rather than sucrose at low temperature. This selective utilization is likely to be controlled by the carbon source uptake and transformation steps, which also reflects an economic calculation balancing energy production and functional plasticity. These findings provide a mechanistic understanding of how a Roseobacter member and possibly others as well counteract polar constraints.
海洋玫瑰杆菌群的成员在全球海洋中无处不在，但它们的冷适应策略几乎没有被研究过。在这里，我们以在极地地区富集的 Loktanella salsilacus 菌株为例，首次通过多组学、酶活性和碳利用程序来描述一种冷适应玫瑰杆菌的代谢特征。与大多数冷适应微生物不同，三羧酸循环通过积累更多的酶分子来增强，而当 L. salsilacus 在 5°C 下生长时，硫代硫酸盐氧化、硫酸盐还原、硝酸盐还原和尿素代谢的基因表达丰度都比在较高温度下低。此外，碳源竞争实验证明，在低温下，葡萄糖比蔗糖更优先被利用。这种选择性利用很可能受到碳源摄取和转化步骤的控制，这也反映了一种在能量产生和功能可塑性之间进行平衡的经济计算。这些发现提供了一种机制上的理解，即一个玫瑰杆菌成员（可能还有其他成员）如何对抗极地限制。
