Growth and carotenogenesis in eight strains ofDunaliella salina Teodoresco from Chile

Abstract

A study was made of growth and carotenogenesis in eight strains of the green alga Dunaliella salina collected from salt ponds at Salar de Atacama (23°30' S; 68°15' W) and Antofagasta (23°39' S; 70°24' W), Chile and kept in unialgal cultures at the Laboratorio Cultivo de Algas, University of Concepcion. The algae were grown in Erdschreiber medium supplemented with 12.5 % w/v NaCI, under a continuous photon flux density of approximately 150 pmol m 2 s-I at 25 + 4 C without aeration. When growth reached the stationary phase, the amount of NaCl was increased to 25%. Total carotenoid content was measured during the exponential growth phase and 20 days after the addition of salt. Strain CONC-001 (Laguna La Rinconada, Antofagasta) exhibited the highest growth rate (k = 0.32 div d-1) and the lowest total carotenoid content (7.2 and 13.7 mg 1-at 12.5 and 25 % NaCl, respectively). Strain CONC-007 (Salar de Atacama) had the lowest growth rate (k = 0.14 div d-') and yielded the highest total carotenes per volume unit (23.1 and 35.6 mg 1-at 12.5 and 25% NaCl) and per cell (ca. 42 pg at 25% NaCl). Total carotenoid synthesis did not increase in strains CONC-001 and CONC-006 with the increase of salinity. These strains had the greatest increase of total carotenoid-to-chlorophyll ratio (4.5-and 9.3-fold, respectively). The seven strains from Salar de Atacama had higher total carotenoid contents than the strain from Antofagasta. Cell size also varied. Strain CONC-001 cells were smallest; strain CONC-006 had the largest cells. There was an inverse correlation between maximum cell density and mean cell size.

Optimization of biomass, total carotenoids and astaxanthin production in Haematococcus pluvialis Flotow strain Steptoe (Nevada, USA) under laboratory conditions

“…Ranges of optimal culture conditions found for different strains may show great disparity. Results obtained by our working group on different strains of Dunaliella salina reinforce this assertion (Cifuentes et al, 1992(Cifuentes et al, , 1996a(Cifuentes et al, , b, 2001Gómez et al, 1999).…”

Carotenogénesis de cinco cepas del alga <i>Dunaliella</i> sp. (Chlorophyceae) aisladas de lagunas hipersalinas de Venezuela

“…En este sentido, Cifuentes et al (1992) informaron que las condiciones ambientales de un hábitat determinado pueden, en parte, ser las responsables del desarrollo de la carotenogénesis en una cepa particular de D. salina. Esta hipótesis se encuentra soportada con nuestros resultados, ya que las cepas Araya y Coche fueron obtenidas en muestras de agua con concentraciones salinas superiores a 30% de NaCl y las restantes cepas a concentraciones inferiores a 20%.…”

“…Los valores obtenidos por la cepa Coche son superiores a los citados por Cifuentes et al (1992), 8.1-42.4 pg.cel -1 para cepas provenientes de Chile (Antofagasta y Atacama); Marín et al (1998), 0.8-1.6 pg.cel -1 en cepas de las salinas de Araya, Venezuela; Gómez et al (2003), 47.7 y 26.9 pg.cel -1 para cepas aisladas de Chile (Atacama) y Egipto (Bardawil Lake), respectivamente, pero menores que los informados por Cifuentes et al (1996), 124 pg.cel -1 para otra cepa aislada del salar de Atacama (Chile). A pesar de que se establecen comparaciones entre el contenido de carotenoides de diferentes cepas de D. salina, resulta difícil analizarlas en todos sus aspectos, debido a que las respuestas en el crecimiento de esta microalga, como lo informa Ben-Amotz (1980), están influenciadas por una serie de factores que interactúan entre sí.…”

“…Dunaliella salina es un alga clorofita predominante en ambientes hipersalinos, caracterizada por acumular grandes cantidades de carotenoides, llegando hasta 14% de su masa seca; lo que la convierte en una fuente potencial de β-caroteno natural de importancia para el uso en las industrias alimenticias y farmacéuticas, así como una herramienta útil para estudios bioquímicos relacionados con biosíntesis de pigmentos y mecanismos de regulación ante ambientes extremos (Borowitzka y Borowitzka 1988, Cifuentes et al 1992, Gómez et al 1992, Masuda et al 2002.…”

Protocol for maximizing the triglycerides-enriched lipids production from &lt;i&gt;Dunaliella salina&lt;/i&gt; SA32007 biomass, isolated from the Salar de Atacama (Northern Chile)

“…Although several reports indicated the D. salina Teodoresco capacity of growing in a wide range of salinity [30][31][32][33], salinities greater than 1 mol/L NaCl (Figure 1) produced a reduction of microalgae biomass at present assays. This result could be related to two factors; first, the D. salina SA32007 strain used for the experiments was cultivated for more than three years in a Johnson Standard medium with a salinity of 0.5 mol/L of NaCl [25,34].…”