Cultivation of Tetraselmis suecica Under Various Nutrient Concentrations and the Characterization of the Algal Biomass

Abstract

Tetraselmis suecica is a candidate for producing 3-deoxy-D-manno-2-octulosonic acid (KDO), a high-value sugar. In this work, a cultivation system was implemented to maintain cultivation conditions and to investigate the effect of media composition on biomass growth and composition. Nitrogen-starved (1.62x10-4 ¬M nitrate), phosphorous-starved (1.11x10-5 M phosphate) and nutrient-replete (5.6x10-4 M nitrate and 3.24x10-5 M phosphate) cultivation conditions were investigated to probe these effects. Total starch, KDO and other sugars in the biomass were determined using enzymatic hydrolysis and GC/MS respectively. Biomass growth was found to be consistent over replicate cultures. For nitrogen-starved, phosphorous-starved and nutrient replete cultures, starch values by percent of total microalgal mass were 42±8%, 39±5% and 43±6% in the stationary phase and maximum cell counts were 4x105, 8x105 and 1.4x105 cells/mL respectively. KDO per gram of lyophilized microalgae found were 20±2, 22±1 and 24±2 mg/g under nitrogen-starved, phosphorous-starved and nutrient-replete conditions respectively at the stationary phase.