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.
Prof. Alexei Solovchenko
Biocapture of Phosphorus From Waste streams With Microalgae: Opportunities and Caveats
Lomonosov Moscow State University, Russia