Cyanobacteria's game of blooms: fast track or endurance run?

Just like humans have the freedom to make life choices, cyanobacteria also possess their own unique survival strategies. Groundbreaking research conducted by Griffith University’s Australian Rivers Institute unveils the fascinating world of cyanobacteria and how they employ phosphorus storage to thrive.

Versatile survivor

Cyanobacteria are among the most common organisms on Earth and are known for their adaptive qualities. These robust organisms first appeared over 3.5 billion years ago, significantly impacting the biosphere’s evolution. Their remarkable ability to survive in a variety of harsh conditions, including intense ultraviolet light, desiccation, hypersalinity, and extreme temperatures, testifies to their hardiness and flexibility.

Cyanobacteria rely heavily on nutrients for survival. Traditionally, nitrogen and phosphorus are recognized as the primary fuels for these organisms. The latest research we published unearthed that under the most nutrient-stressed conditions, cyanobacteria can substitute these nutrients with sulfur, demonstrating an incredible degree of versatility.

The latest research from Griffith University provides yet another fascinating insight: not only can cyanobacteria switch their nutrient sources, but they also exhibit a remarkable ability to regulate their nutrient consumption, enabling them to enhance their longevity.

Bet-Hedging Strategy

Associate Professor Man Xiao explains that blue-green algae have evolved ingenious ways to hoard nutrients. This tactic enables algal blooms to persist and even expand, despite an apparent absence of nutrients in their environment.

The research specifically focuses on the cyanobacterium species  Raphidiopsis raciborskii  and  Chrysosporum ovalisporum . Notably,  R. raciborskii  is reported to be the dominant species in over 18% of freshwater cyanobacterial blooms worldwide. The study investigates the nutrient hoarding and usage strategies of these two cyanobacteria species, under differing levels of nitrogen and phosphorus availability.

Findings reveal a remarkable divergence in survival strategies among cyanobacteria. Some species rapidly absorb available nutrients, leading to swift growth. In contrast, others store nutrients and grow at a slower pace, enabling them to survive for longer periods. This clever survival tactic can be likened to a bet-hedging strategy, according to Associate Professor Man Xiao. The cyanobacteria are effectively deciding to either “grow quickly and outcompete your competitors or store the nutrients, grow slowly, and gradually replace other species who have run out of nutrients,” she explains.

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Taxonomy

• Bacteria
• Algal Blooms