Аннотация:Phosphorus (P) is central to storing and exchange of energy and information in cell including that of microalgae. Overwhelming majority of microalgae are naturally acclimated to low-P environments hence they are capable of taking up and storing P in large amounts whenever it becomes available. The ability to take up more P than is necessary for immediate growth is termed “luxury uptake.” Understanding this phenomenon constitutes a crucial insight into nutrient-driven processes in natural algal communities e.g. harmful algae blooms as well as to operation of algae-based technologies for sustainable usage of P e.g. recycling of the nutrient from wastewater to biofertilizers. The bulk of P acquired during luxury uptake is stored in form of inorganic polyphosphate, the compound with nearly ubiquitous presence and multifaced function in the cell. Although seminal works on luxury P uptake and polyphosphate metabolism were carried out fifty years ago, application of modern “omics” approaches and advanced imaging microscopy techniques enabled obtaining a deeper mechanistic insight into these processes. Nevertheless, our knowledge about luxury P uptake remains much more limited in comparison with that about P shortage and mechanism tolerance to this stress in microalgae. In this review, the knowledge of luxury P uptake originating from classical phycological and biochemical methods is confronted to the recently obtained understanding of molecular mechanisms of P transport to the cell, polyphosphate biosynthesis, regulation and genetic control of these processes. Biotechnological implications of the knowledge about luxury P uptake accumulated to the date are discussed in the context of algae-based approaches for sustained usage of nutrients and industrial cultivation of microalgae.