Growth and biochemical composition of Spirulina platensis dry biomass in diluted monosodium glutamate waste waters

The use of low-cost culture media is important for the development of large-scale Spirulina platensis production. This study aims to investigate the effects of using diluted monosodium glutamate wastewater (MSGW) as a culture medium on the growth and biochemical composition of S. platensis dry biomass. Nitrogen and phosphorus uptake by S. platensis from MSGW media was also investigated in this study. Four concentrations of MSGW have been used in this study, namely 1.5, 2.5, 3.5 and 4.5 mL/L and Walne medium was used as a control. All media were adjusted at pH 9 and S. platensis culture was carried out for 14 day at 36.0C, 77% relative humidity, 5000 lux light intensity and aeration rate at 0.7 L/min. The results of this study have indicated that the growth, protein, lipids, carbohydrates and chlorophyll of S. platensis biomass at 2.5 mL/L MSGW concentrations were not significantly different from Walne medium, but were significantly different from 1.5, 3.5 and 4.5 mL/L MSGW concentrations. The present study have also shown those nitrogen and phosphorus uptakes by S. platensis from 2.5 mL/L MSGW concentration was not significantly different from Walne medium, but were significantly different from 1.5, 3.5 and 4.5 mL/L MSGW concentrations. The present study concluded that S. platensis can be cultivated in MSGW as a medium with an optimum concentration of 2.5 mL/L. This finding will serve as a basic reference for future studies to utilize MSGW for microalgae culture media.