Production of arthrospira (Spirulina) platensis enriched in β-glucans through phosphorus limitation

Abstract

(1) Background: Arthrospira (commonly known as Spirulina) is an edible cyanobacterium that is produced worldwide as a food supplement owing to its high nutritional value. Arthrospira displays strong potential as an important ingredient in the development of novel functional foods. Polysaccharides from Arthrospira are biologically active compounds and hence there is interest in producing biomass rich in carbohydrates. (2) Methods: A. platensis was cultivated under different degrees of phosphorus limitation in order to trigger the accumulation of carbohydrates. The biomass was then characterized in terms of its content of α-and β-glucans, total dietary fiber and monosac-charide profile. Fourier-transform infrared spectroscopy (FTIR) was used for the rapid analysis of the main biomass components. (3) Results: Phosphorus limitation resulted in an increase in carbohydrates (from 23% up to 65% dry biomass) of which 4–12% (in relation to the dry biomass) was α-glucans and 20–34% was 1.3:1.6 β-glucans, while 1.4:1.6 β-glucans were not detected. Total dietary fibers ranged from 20–32% (of dry biomass), whereas among the carbohydrates, the predominant monosaccharide was glucose (>95%). FTIR performed well when applied as a prediction tool for the main biomass components. (4) Conclusions: Since β-glucans are of particular interest as biologically active compounds, this study demonstrates that phosphorus-limited A. platensis could be a potential ingredient for the development of novel functional foods.