Prof. Alexei Solovchenko

Nowadays, sustainable usage of mined phosphorus (P) is a major concern for humanity. The rock phosphate used for production of chemical P-fertilizer, the lifeblood of modern agriculture, is a finite non-renewable resource very unevenly distributed between countries of the world. Despite this, current routines of P processing and usage are woefully inefficient meaning that > 80% of mined P ends up as non-recycled waste. A significant part of this waste is comprised of liquid waste- or side-streams.  At the same time, the P-rich waste-streams are a valuable source of nutrients for cultivation of microalgae. Conversely, microalgal cultures are a promising vehicle for bioremoval of the excessive P with concurrent treatment of wastewater with co-generation of environment-friendly slow-release biofertilizer. These photosynthetic microorganisms feature the capability of taking P in a large excess of the current metabolic demand (known as ‘luxury P uptake’) and stockpile it as inorganic polyphosphate in the cell against future shortage. Still, efficient application of microalgae for sustainable usage of P is limited by our insufficient knowledge of the biology of a photosynthetic cell in the P-eutrophicated media.  The present talk summarizes the recent progress in the research on luxury P uptake. The mechanisms of P uptake by a microalgal cell as a function of its P-nutrition status are elucidated. An overview is given of the ultrastructural aspects of intracellular storage of P. Implications of the recent findings for biotechnology and environment protections are considered.