The Culture And Nutritional Value Of Spirulina Platensis Under Industrialized Conditions

Spirulina platensis cultured in the new photobioreactors was studied in this paper. thecell density and productivity of S. platensis cultured in different light-path(5cm,8cm,10cm,15cm,20cm) photobioreactors and different seasons(spring autumn) were compared;The nutrition compositions of S. platensis cultured in different light-path photobioreactorswere analyzed and compared; The effect of different addition of NaHCO3in the medium of S.platensis was analyzed and compared; The productivity and the the nutrition compositions ofS. platensis and S.maxima were compared; The extraction and purification of pigments in theS. platensis were optimized; The effect of LED lamp on growth of S. platensis were studied.The maximal cell density in8cm and10cm light-path photobioreactor in autumn was higherthan that in spring. The maximal cell density in8cm light-path photobioreactor in autumn was1.58g/L, which was the highest in all of the photobioreactors and the tested seasons. Thecomparison of the maximal cell density in15cm and20cm light-path photobioreactor betweenspring and autumn was not significant. The highest productivity reached29.92g/m2d in20cm light-path photobioreactor. In spring, The8cm light-path photobioreactor was notsuggested to use in the greenhouse for production of S. platensis because of the difficulty ontemperature controlling. The20cm light-path photobioreactor was most suggested for use of S.platensis production, because of the cell density and productivity were the highest.Compared with outdoor open raceway culture pattern, The closed photobioreacter culturepattern could obviously reduce the possibility of contamination and increase the cell densityand productivity.The nutrition compositions of S. platensis in different light-path photobioreactor weredifferent. The contents of protein and phycocyanin increased with the increase on light-path ofphotobioreactors. The contents of carbohydrate, lipids and chlorophyll a decreased with theincrease of light-path of photobioreactors. The comparison of the nutrition compositions of S.platensis in different season was significantly different. The cintents of protein andphycocyanin were not significant, while the contents of carbohydrate, crude fat andchlorophyll a were significantly diffenernt (p<0.05).The S. platensis production with addition of5g/L NaHCO3in the medium could reach thehighest economic benefits, but it was more easy be contaminated. So the S. platensis was cultured in10g/L NaHCO3medium.S. platensis and S.maxima was cultured under same conditions and in the same light-pathreactors. The reasuts showed that the maximium cell density and productivity of S. platensiswere higher than that of S. maxima. The nutrition compositions of S. platensis were higherthan that of S. maxima except carbohydrate.The optimal conditions for isolation and purification of phycocyanin from S. platensis werestudied. The results indicated that after the salting-out with55%saturation of ammoniasulfate and column chromatography, the highest purified fold of phycocyamin reached3.4.Two kinds of Led lamps were tested for cultivation of S. platensis. The results showed thatthe alga growed better in the culture with more red light than that with more blue light. Thatindicated more red light was better for growth of Spirulina.