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Title: Polysaccharide production by microalgae. Final report on phase 1

Technical Report ·
OSTI ID:6698889

The feasibility of producing commercially valuable polysaccharides from microalgal biomass was demonstrated. Algal biomass with a high polysaccharide content was produced by subjecting cultures to short periods of nitrogen limitation without decreasing overall biomass production rates. Three different algae were studied--unicellular blue-green alga Synechococcus leopoliensis, filamentous blue-green alga Spirulina platensis, and a green colonial alga, Scenedesmus sp. Batch cultures were grown with varying amounts of nitrate to limit nitrogen uptake at various stages in the batch growth curve. In the presence of high nitrate concentrations, the Synechococcus culture became stationary within four days, whereas both Spirulina and Scenedesmus maintained an appreciable growth rate and high daily productivities, for at least a week. With limiting nitrate concentrations, the cellular content of polysaccharide (measured as total carbohydrates) increased markedly, from 20-25 percent to 70-80 percent in Synechococcus and Spirulina. Depending on the level of nitrate used, onset of nitrogen limitation could be set at various culture densities. In all cases, little or no inhibition of total biomass production was noted.

Research Organization:
Ecoenergetics, Inc., Vallejo, CA (USA)
OSTI ID:
6698889
Report Number(s):
PB-84-179449
Country of Publication:
United States
Language:
English