Carotenogénesis de cinco cepas del alga &lt;i&gt;Dunaliella&lt;/i&gt; sp. (Chlorophyceae) aisladas de lagunas hipersalinas de Venezuela

Miguel Guevara,Néstor Rosales,Aléikar Vázquez,César Lodeiros,Nathalie Lemus,Lolymar Romero,Paulino Núñez,Olga Gómez

doi:10.15517/rbt.v53i3-4.14593

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

Miguel Guevara, Néstor Rosales + Show 6 more

Open Access

https://doi.org/10.15517/rbt.v53i3-4.14593

Copy DOI

Abstract

We evaluated discontinuous cultures (Algal medium at 0.5 mM of NaNO3, and 27% NaCI) of five strains of Dunaliella sp. isolated from Venezuelan hypersaline lagoons (Araya, Coche, Peonia, Cumaraguas. and Boca Chica) and one strain from a reference collection (Dunaliella salina, LB1644). Cultures were maintained to 25+/-1 degrees C, with constant aeration, photoperiod 12:12, and two light intensities (195 and 390 microE.m(-2).s(-1)) during 30 days. Cell count was recorded on a daily basis using a Neubaüer camera. Totals of chlorophyll a and carotenoids were measured at the end of the experiment. The largest cellular densities were measured during the smallest light intensities. The strain with the largest cellular density was isolated from Boca Chica (8 xl0(6) and 2.5 xl0(6) cel.ml(-1) a 390 and 195microE.m(-2).s(-1), respectively). The increment of light intensity produced a significant reduction of growth rates in all strains. Totals of carotenoids by volume were as large as 390 microE.m(-2).s(-1). Strains LB 1644, from Coche and Araya were those that produced the largest amount of carotenoids (38.4; 32.8 and 21.0 microg.ml(-1), respectively). Differences total carotenoids by cell between treatments were significant. The largest concentration was 390 microE.m(-2).s(-1). The strains LB 1644 and Coche produced the highest values of carotenes (137.14 and 106.06 pg.cel(-1), respectively). Differences in the relation carotenoid:chlorophyll a between the strains at various light intensities was significant. Strains LB1644 presented the largest value of the relation carotenoids:chlorophyll a (20:1) at 195 microE.m(-2).s(-1). No significant differences were detected in the strain Coche (15:1). All the other strains showed relations lower than one. Our results suggest that the strains of Coche and Araya show potential to be used in the biotechnology of carotenoids production.

Highlights

Diversos estudios han demostrado que la producción de carotenoides en D. salina puede optimizarse mediante variaciones de las condiciones de cultivo, las cuales incluyen aumento de la salinidad, intensidad luminosa, temperatura (Ben-Amotz 1987, Gómez et al 2003) y/o limitación de nutrientes (Borowitzka y Borowitzka 1988, Borowitzka et al 1990, Mendoza et al 1999)
We evaluated discontinuous cultures (Algal medium at 0.5 mM of NaNO3, and 27% NaCl) of five strains of Dunaliella sp. isolated from Venezuelan hypersaline lagoons (Araya, Coche, Peonía, Cumaraguas, and Boca Chica) and one strain from a reference collection (Dunaliella salina, LB1644)
Cultures were maintained to 25±1 °C, with constant aeration, photoperiod 12:12, and two light intensities (195 and 390 μE.m-2.s-1) during 30 days

Summary

Introduction

Diversos estudios han demostrado que la producción de carotenoides en D. salina puede optimizarse mediante variaciones de las condiciones de cultivo, las cuales incluyen aumento de la salinidad, intensidad luminosa, temperatura (Ben-Amotz 1987, Gómez et al 2003) y/o limitación de nutrientes (Borowitzka y Borowitzka 1988, Borowitzka et al 1990, Mendoza et al 1999). El incremento de la intensidad luminosa en los cultivos produjo una disminución significativa de las tasas de crecimiento, particularmente con las cepas de Coche y la cepa de referencia (Fig. 2).

Results

Conclusion