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Copyright of Acta Biológica Colombiana is the property of Universidad Nacional de Colombia, Facultad de Biologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Colombiana de Biotecnología is the property of Universidad Nacional de Colombia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Changes in salinity, temperature and irradiance during wet and dry seasons have induced metabolic versatility in cyanobacteria from saline environments. Cyanobacteria from these environments have biotechnological potential for the production of metabolites with pharmaceutical and industrial interest. We studied the growth, dry mass and metabolite production of the cyanobacterium Synechococcus sp. MOF-03 in function of irradiance (78, 156 and 234 μmol q m-2 s-1). All batch cultures were maintained by triplicate in constant aeration, 12:12 h photoperiod, 30 ±2°C and 35‰. Maximum values of protein, carbohydrates and lipids, of 530.19 ±11.16, 408.94 ±4.27 and 56.20 ±1.17 μg ml-1, respectively, were achieved at 78 μmol q m-2 s-1. Pigments, analyzed by HPLC, showed maximum values at 78 μmol q m-2 s-1 for chlorophyll a with 7.72 ±0.16 μg ml-1, and at 234 μmol q m-2 s-1 for β-carotene and zeaxanthin with 0.70 ±0.01 and 0.67 ±0.05 μg ml-1. Chlorophyll a:β-carotene ratio decreased from 17.15 to 6.91 at 78 and 234 μmol q m-2 s-1; whereas β-carotene:zeaxanthin ratio showed no changes between 78 and 156 μmol q m-2 s-1, around 1.21, and decreased at 234 μmol q m-2 s-1, to 1.04. Also, this cyanobacterium produced the greatest cell density and dry mass at 156 μmol q m-2 s-1, with 406.13 ±21.74 x106 cell ml-1 and 1.49 ±0.11 mg ml-1, respectively. Exopolysaccharide production was stable between 156 y 234 μmol q m-2 s-1, around 110 μg ml-1. This Synechococcus strain shows a great potential for the production of enriched biomass with high commercial value metabolites. [ABSTRACT FROM AUTHOR]

The study of cyanobacteria isolated from hypersaline environments is of interest because of their metabolic and ecophysiologic versatility in adapting to extreme conditions of salinity, temperature, irradiance and nutrient availability. The effect of salinity at 0‰, 35‰, 70‰ and 100‰ on the growth, dry weight, and pigment, protein, carbohydrate and lipid production of the cyanobacterium Synechococcus sp. was determined. Bioassays were kept in ALGAL medium equivalent to 8 mM NaNO3, constant aeration, 12:12 h photoperiod, 28 ± 2°C and 156 μmol quanta m-2 s-1 of irradiance. The cyanobacterium was able to grow under all salinities tested. Cell density was optimized at 35‰, with 607.64 ± 14.35 cells mL-1. The highest values of dry weight (3.87 ± 0.03 ng cell-1), chlorophyll a (41.86 ± 0.39 fg cell-1), β-carotene (9.03 ± 0.15 fg cell-1), zeaxanthin (9.74 ± 0.24 fg cell-1), proteins (1.95 ± 0.05 pg cell-1) and carbohydrates (1.80 ± 0.05 pg cell-1) were obtained at 100‰; however, the highest lipid content (0.45 ± 0.04 pg cell-1) was reached at 0‰. This Synechococcus strain shows halotolerance and the capacity to modulate the production of enriched biomass with pigments, proteins, carbohydrates and lipids in terms of salinity. [ABSTRACT FROM AUTHOR]