Resumo

FUENMAYOR, Gisela; JONTE, Lorena; ROSALES-LOAIZA, Néstor  e  MORALES, Ever. Growth of the marine cyanobacteria Oscillatoria sp MOF-06 in relation to pH in discontinuous cultures. Rev. Soc. Ven. Microbiol. [online]. 2009, vol.29, n.1, pp.21-25. ISSN 1315-2556.

Growth, pigment content, carbohydrates, exopolysacharides and proteins were evaluated in the marine cyanobacteria Oscillatoria sp. in discontinuous cultures at pH 6, 7, 8 and 9. All cultures were done in triplicate in ALGAL culture medium, at 3.5% salinity, constant airing, 28 ± 2^oC, 156 µmol m^-2 s^-1 illumination, and 12:12h photoperiod. Cultures at pH 9 and controls (pH 9-11), reached the highest turbidity and dry mass values. The α chlorophyll content was higher in the exponential phase, at pH 9 and control, while the  lowest values were detected at pH 6 and 7. Protein and carbohydrate content also increased with pH in the following order: control>9>8>7>6. On the other hand, Oscillatoria produced more exopolysacharides at pHs between 6 and 8. These results show that the marine cyanobacteria Oscillatoria sp. MOF-06 increases its biomass production, and chlorophyll, protein and carbohydrate content under alkaline conditions, while this pH induces a decrease of exopolysacharide production, but without affecting the carotenoid content

Palavras-chave : Oscillatoria sp; growth; pH; pigments; exopolysacharides.