Changes in Content, Constituents and Distribution of Constitutive and Excreted Sugars of Spirulina (Arthrospira) Maxima in Nutrient-Limited Batch Cultures

Abstract

Changes in content, constituents and distribution of constitutive and excreted sugars of Spirulina (Arthrospira) maxima in nitrogen or sulfur-limited batch cultures were investigated in this study, The changes were influenced by both age of the culture and availability of nitrogen or sulfur in the medium. Increases in percentage of the constitutive sugars (PSC) took place at the beginning of the decelerating phase. The increase was mainly due to the accumulation of internal soluble polysaccharides (SIPS). The maximal concentration of PSC per unit volume of reactor was obtained at the beginning of the death phase, at which time cells from nitrogen-limited batch cultures contained about 66% of sugars. SIPS representing 76% of PSC consisted of mainly glucose. The monosaccharide of cell wall polysaccharides (CWPS) was also glucose. Sugars from the external layers (PSEL) or from culture medium (PSCM) contained a mixture of monosaccharides. Selective fractionation of PSCM, PSEL, SIPS and CWPS was obtained by a sequential extraction procedure.