Gregoracci Gustavo Bueno, Soares Ana Carolina Dos Santos, Miranda Milene Dias, Coutinho Ricardo, Thompson Fabiano L
Departamento de Ciências do Mar, UNIFESP Baixada Santista. Santos, SP, Brazil; Instituto de Biologia, Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ, Brazil.
Instituto de Biologia, Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ, Brazil.
PLoS One. 2015 Sep 1;10(9):e0137090. doi: 10.1371/journal.pone.0137090. eCollection 2015.
Although previous studies have described opposing states in upwelling regions, i.e., the rise of cold nutrient-rich waters and prevalence of surface warm nutrient-poor waters, few have addressed the transition from one state to the other. This study aimed to describe the microbial and viral structure during this transition and was able to obtain the taxonomic and metabolic compositions as well as physical-chemical data. This integrated approach allowed for a better understanding of the dynamics of the downwelling upwelling transition, suggesting that a wealth of metabolic processes and ecological interactions are occurring in the minute fractions of the plankton (femto, pico, nano). These processes and interactions included evidence of microbial predominance during downwelling (with nitrogen recycling and aerobic anoxygenic photosynthesis), different viral predation pressures over primary production in different states (cyanobacteria vs eukaryotes), and a predominance of diatoms and selected bacterial and archaeal groups during upwelling (with the occurrence of a wealth of nitrogen metabolism involving ammonia). Thus, the results provided insights into which microbes, viruses and microbial-mediated processes are probably important in the functioning of upwelling systems.
尽管先前的研究已经描述了上升流区域的相反状态，即冷的富营养水的上升以及表层暖的贫营养水的普遍存在，但很少有研究涉及从一种状态到另一种状态的转变。本研究旨在描述这种转变过程中的微生物和病毒结构，并能够获得分类学和代谢组成以及物理化学数据。这种综合方法有助于更好地理解下沉-上升转变的动态过程，表明在浮游生物的微小部分（飞摩尔、皮摩尔、纳摩尔）中发生了大量的代谢过程和生态相互作用。这些过程和相互作用包括下沉期间微生物占主导地位的证据（伴随着氮循环和有氧无氧光合作用）、不同状态下病毒对初级生产的不同捕食压力（蓝细菌与真核生物），以及上升期间硅藻和特定细菌及古菌类群的占主导地位（伴随着大量涉及氨的氮代谢的发生）。因此，研究结果为哪些微生物、病毒和微生物介导的过程可能对上升流系统的功能很重要提供了见解。
