Abstract
Despite the crucial role of polyphosphate (polyP) in aquatic environments, its metabolism in cyanobacteria responding to nutrients is poorly understood. We investigate polyP in three cyanobacteria species, specifically unicellular picocyanobacteria, under various nutritional conditions. Our experiments show that the accumulation of polyP in cyanobacteria is strongly dynamic, depending on phosphate levels and growth stages. ‘Overplus’ uptake of phosphorus (P) during the lag phase leads to the rapid accumulation of polyP, followed by lower polyP quotas during the exponential growth stage as a result of competing ‘luxury’ P uptake and polyP utilization to support rapid cell division. Cyanobacteria are capable of P deficiency responses that preferentially maintain polyP. However, preferential utilization of polyP occurs under severe P stress, suggesting the crucial role of polyP as P reserve to support cellular survival. Strong variability was observed among different species of cyanobacteria in their ability to accumulate polyP, and likely in the threshold P levels at which preferential polyP degradation occurs. This suggests that some cyanobacteria may be more adaptive to P-stressed or P-fluctuating conditions. Our results explain and provide important insights into the variability of polyP observed in aquatic environments where picocyanobacteria are the dominant primary producers.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 572-583 |
| Number of pages | 12 |
| Journal | Environmental microbiology |
| Volume | 21 |
| Issue number | 2 |
| DOIs | |
| State | Published - Feb 1 2019 |
Bibliographical note
Funding Information:We thank Maryam Jahromi, Oleksandra Kaskun, Zach DiLoreto, Stefan Markovic, Tingting Zhu, Sue Watson (University of Waterloo, Canada) and Yuge Bai (University of Tubingen, Germany) for intellectual input and technical assistance. We acknowledge Arthur Zastepa (Canada Centre for Inland Waters, Environment and Climate Change Canada) for sharing laboratory facilities. We thank Toshi-kazu Shiba (Matsumoto University, Japan) for providing polyphosphate standards. STEM images were obtained with the help of Charles Soong at the Ontario Centre for the Characterization of Advanced Materials at the University of Toronto. The Natural Sciences and Engineering Research Council (NSERC) Discovery Grant and Canada foundation for innovation (CFI) provided funding to MD for this project. The authors have no conflict of interest to declare.
Funding Information:
We thank Maryam Jahromi, Oleksandra Kaskun, Zach DiLoreto, Stefan Markovic, Tingting Zhu, Sue Watson (University of Waterloo, Canada) and Yuge Bai (University of Tubingen, Germany) for intellectual input and technical assistance. We acknowledge Arthur Zastepa (Canada Centre for Inland Waters, Environment and Climate Change Canada) for sharing laboratory facilities. We thank Toshikazu Shiba (Matsumoto University, Japan) for providing polyphosphate standards. STEM images were obtained with the help of Charles Soong at the Ontario Centre for the Characterization of Advanced Materials at the University of Toronto. The Natural Sciences and Engineering Research Council (NSERC) Discovery Grant and Canada foundation for innovation (CFI) provided funding to MD for this project. The authors have no conflict of interest to declare.
Publisher Copyright:
© 2018 Society for Applied Microbiology and John Wiley & Sons Ltd.