Ferrera Isabel, Sánchez Olga, Kolářová Eva, Koblížek Michal, Gasol Josep M
Departament de Biologia Marina i Oceanografia, Institut de Ciències del Mar, CSIC, Barcelona, Catalunya, Spain.
Departament de Genètica i de Microbiologia, Universitat Autònoma de Barcelona, Bellaterra, Catalunya, Spain.
ISME J. 2017 Oct;11(10):2391-2393. doi: 10.1038/ismej.2017.79. Epub 2017 May 23.
Aerobic anoxygenic phototrophic (AAP) bacteria are microorganisms that can harvest light energy using bacteriochlorophyll a to supplement their predominantly organotrophic metabolism. Growth enhancement by light has repeatedly been demonstrated in laboratory experiments with AAP isolates. However, the ecological advantage of light utilization is unclear, as it has never been proven in the natural environment. Here, we conducted manipulation experiments in the NW Mediterranean and found that AAP bacteria display high growth rates which are controlled to a large extent by intense grazing pressure and phosphorous availability. Foremost, we found that, contrarily to the bulk bacterioplakton, AAP bacteria display higher growth rates when incubated under light-dark cycles than in complete darkness. These results represent the first direct evidence that natural populations of marine AAP bacteria can be stimulated by light.
好氧不产氧光合（AAP）细菌是一类微生物，它们能够利用细菌叶绿素a获取光能，以补充其主要的有机营养代谢。在对AAP分离株进行的实验室实验中，光促进生长的现象已被多次证实。然而，利用光的生态优势尚不清楚，因为在自然环境中从未得到证实。在此，我们在地中海西北部进行了操纵实验，发现AAP细菌具有较高的生长速率，这在很大程度上受强烈的捕食压力和磷的可利用性控制。首先，我们发现，与大部分浮游细菌相反，AAP细菌在明暗循环条件下培养时比在完全黑暗条件下具有更高的生长速率。这些结果首次直接证明了海洋AAP细菌的自然种群能够受到光的刺激。
