Effects on C-phycocyanin content of Arthrospira (Spirulina) platensis of culture medium containing geothermal water.

Abstract

This research aimed to compare effects on product quality and algal growth of inoculation ratio of Arthrospira platensis in the culture medium containing 20% geothermal water. A. platensis was inoculated at the ratio of 1/6, 1/10, and 1/20 of nutrient medium volume (2500 mL). The experiment medium was prepared with 20% geothermal water and 80% distilled water. Schlösser medium, 100% geothermal water medium, and 100% distilled water were used as the control group. At the end of the experiment, Spirulina biomass was obtained by filtration through 80-micron plankton cloth and freeze-dried at -60 °C. Increasing inoculation density shortened the culture time and increased the growth rate compared to the other groups. The best growth among the experimental groups was obtained in a 1/6 ratio inoculated Spirulina group in a 20% geothermal water medium. Among the experimental groups, dry biomass was obtained in the Spirulina group inoculated at 1/6 in only 20% geothermal water medium. The optical density value was 0.989 (A750), and the biomass yield was 0.476 g/L in the experimental group, the highest among the Schlösser groups was 1.259 (A750), and the biomass yield was 0.928 g/L. The most efficient growth and phycocyanin content was determined in the 1/6 inoculated groups. The phycocyanin content in the experimental group was found in 22.49%, and the purity rate was 2.24. In control groups, 3.73 purity and 28.62% phycocyanin were determined in the Schlösser medium. While 48.42% protein was detected in the geothermal water group, 61.64% was obtained with the Schlösser medium.