Cyanobacterial biomass production in saline media

The cultivation, growth patterns, and physiological activities of the marine cyanobacterium (blue-green alga)Spirulina subsalsa were studied. A comparison of its growth in three different media (diluted seawater, seawater, and seawater +0.5 M NaCl) revealed a faster growth in the hypersaline medium. In the hypersaline medium, the culture was homogeneous, in contrast to the aggretates formed in the lower-salt media. Enzymic analysis of the cells demonstrated selective sensitivity of soluble malate dehydrogenase to sodium ions, while chloride ions or nonionic solutes caused no inhibition. The membrane-associated enzyme ferredoxin-NADP reductase was only partially sensitive to sodium ions. The respiratory enzymes exhibited well-coupled activity, and faster respiration was observed with the preparation from the hypersaline culture.