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Spirulina Culture using Reject Brine Water from Desalination Plants
(2000-p
resent/ Research Team: J. Perret, M. Claereboudt, B. Jupp)

     
a) microbial mats forming domes in the hypersaline Wadi Mugshyn; b) cross-section in an algal gypsum-encrusted dome, c) filament of  Spirulina from Wadi Mugshyn, Oman.

 

Economical potential of microalgae production is becoming increasingly recognized. Among microalgae currently of commercial significance, Spirulina stands out because of tits high value.  In 1985, food-grade Spirulina prices were ranging between US $ 15,000 to US $ 30,000 per metric ton . In the late 1980s, the worldwide production of Spirulina for food was 850 metric tons produced on 10 farms with a total of 35.6 hectares in cultivation (Parker et al., 1992). Today, the commercial production is about 2500 metric tons per year. Fox (1996) mentioned that Spirulina production has the potential to become a multi-million ton commodity in the near future. 

 

Like their ancestral types, these organisms are often adapted to extreme conditions of temperature, alkalinity and salinity. This is helpful as, once a culture is established there is little chance of contamination by eukaryotic algae and very little competition from other cyanobacteria.  Spirulina is particularly attractive because of its adaptation to brackish water (salt at 20-70 g/L is optimal but 1-270 g/L is tolerated), and its relative ease of harvest by flotation and filtration. High alkalinity is required to grow SpirulinaThe optimum pH ranges from 8.3 to 11.0 (Richmond, 1988). Light availability is a dominant factor of this photoautotrophic alga.  Spirulina requiresCO2 as a carbon source to support its photosynthetic metabolism. In addition, Spirulina is a thermophilic alga; its optimum growth temperature ranges between 35 and 37 oC.

 

 

 

The characteristics of reject brine water from desalination plants (i.e., high alkalinity and salinity) and the climatic condition of the Gulf Countries (i.e., high solar radiation and high temperatures) may provide an ideal growth medium for Spirulina. Thus, instead of considering reject brine water as a waste, it could be used as a growing environment for Spirulina.The principal objective of this project is to investigate the potential of Spirulina as culture crop using reject brine water from desalination as a growth medium.  The first stage of the project involves the isolation of local strains of Spirulina. Samples of extremophile algae will be collected from natural hypersaline ponds in Oman. Spirulina strains will be isolated in order to develop a laboratory scale culture of Spirulina. The second stage involves optimization of growth conditions of the selected algal strain using reject brine from both inland and seawater desalination plants. The algal cultures will be maintained under lights by sub-culturing and then used in comparative experiments on salinity/nutrient/temperature effects in parallel with commercial strains of Spirulina (i.e., Arthospira Platensis).  The anticipated results are excepted to support the development Spirulina production using reject brine water in the Gulf region. This project will contribute to “decrease the cost of desalination” by generating secondary revenue from a high-value algae culture for both inland sea-based brine disposal.  (Click here for more info)


© 2000 Johan Perret