Iakovchuk Nadezhda, Fabian Jenny, Dellwig Olaf, Hassenrück Christiane, Schulz-Vogt Heide N
Department of Biological Oceanography, Leibniz Institute for Baltic Sea Research Warnemünde, Rostock, Germany.
Faculty of Mathematics and Natural Sciences, University of Rostock, Rostock, Germany.
Appl Environ Microbiol. 2025 May 21;91(5):e0233024. doi: 10.1128/aem.02330-24. Epub 2025 Apr 30.
Filamentous sulfide-oxidizing spp., which occasionally form extensive white microbial mats, are widespread in marine coastal environments and can achieve significant biomass because of their large size. Their ability to store phosphates in the polymerized form of polyphosphates makes them potential key players in altering the phosphorus (P) cycle at the sediment-water interface. This study examined phosphate uptake and polyphosphate formation in a P-starved culture of sp. 35Flor strain. Remarkably, even after sustained P starvation over five generations, the mat establishment rate of the examined culture was 46%, demonstrating considerable plasticity in response to different levels of phosphate availability. Under these P-depleted conditions, at least 17% of filaments still contained polyphosphates, highlighting their critical role in their metabolism. Upon reintroduction of phosphate to starved cultures, an extremely rapid phosphate uptake was observed within the first 10 min, with rates reaching up to 12.4 mmol phosphate g protein h, which is significantly higher than values previously reported in the literature for similar-sized organisms. The high phosphate uptake capacity of spp., estimated at 0.6-6 mmol m d for typical densities of filaments in coastal sediments, suggests that under certain environmental conditions, these bacteria could act as a P sink and thus play an important role in benthic P cycling.
Sulfide-oxidizing bacteria of the genus occur ubiquitously in marine coastal sediments and have a large potential to influence phosphate fluxes at the sediment-water interface, owing to their ability to accumulate polyphosphate and their large size. However, the extent to which these bacteria can contribute to phosphorus (P) sequestration or release remains poorly assessed. The importance of this study lies in demonstrating the remarkable flexibility in the adaptation of the strain sp. 35Flor to varying P availability, including prolonged P starvation and its capacity to rapidly uptake and store available phosphate in the form of polyphosphate. When considered on a global scale, these physiological traits could form the basis for 's role in moderating P fluxes.
丝状硫化物氧化菌偶尔会形成广泛的白色微生物垫，在海洋沿岸环境中广泛分布，由于其体型较大，能够积累可观的生物量。它们以多聚磷酸盐的聚合形式储存磷酸盐的能力，使其成为改变沉积物 - 水界面磷（P）循环的潜在关键参与者。本研究检测了35Flor菌株在缺磷培养条件下的磷酸盐摄取和多聚磷酸盐形成情况。值得注意的是，即使在连续五代缺磷的情况下，所检测培养物的垫形成率仍为46%，这表明其对不同磷酸盐可利用水平具有相当大的可塑性。在这些缺磷条件下，至少17%的丝状体仍含有多聚磷酸盐，突出了它们在代谢中的关键作用。当向饥饿培养物中重新添加磷酸盐时，在最初的10分钟内观察到极其快速的磷酸盐摄取，速率高达12.4 mmol磷酸盐·g蛋白·h，这显著高于文献中先前报道的类似大小生物体的值。对于沿海沉积物中典型丝状体密度，该菌的高磷酸盐摄取能力估计为0.6 - 6 mmol·m⁻²·d，这表明在某些环境条件下，这些细菌可作为磷汇，从而在底栖磷循环中发挥重要作用。
该属的硫化物氧化细菌普遍存在于海洋沿岸沉积物中，由于它们能够积累多聚磷酸盐且体型较大，因此在影响沉积物 - 水界面的磷酸盐通量方面具有很大潜力。然而，这些细菌对磷固存或释放的贡献程度仍评估不足。本研究的重要性在于证明了35Flor菌株在适应不同磷可用性方面具有显著的灵活性，包括长期缺磷以及其以多聚磷酸盐形式快速摄取和储存可用磷酸盐的能力。从全球范围来看，这些生理特性可能构成该菌在调节磷通量方面作用的基础。
