title: Physiological characterization of Dunaliella sp. (Chlorophyta, Volvocales) from Yucatan, Mexico.
abstract: Physiological responses of Dunaliella salina and Dunaliella viridis, isolated from solar saltworks on the Yucatan Peninsula, were studied. Optimal growth temperature for D. salina was 22 degrees C (3.06 x 10(6) cells mL(-1)) and 26 degrees C for D. viridis (4.04 x 10(6)cells mL(-1)). Total carotenoid content in D. salina increased with temperature to a maximum of 35.14 pg cell(-1) at 38 degrees C. Dunaliella salina alpha-carotene and beta-carotene content was 0.083+/-0.003 and 0.598+/-0.020 mg 100g dry wt(-1) respectively, whereas lower values were found in D. viridis cultured under same experimental conditions (0.018+/-0.002 and 0.136+/-0.012 mg 100g dry wt(-1) respectively). The highest specific growth rate in D. salina was obtained at 10% NaCl (0.28 d(-1)), while its cell volume increased from 524 to 2066.93 microm(3) when cultured from 10% to 35% NaCl. Maximum photosynthetic rates were attained when increasing from optimal growing temperature to 30 degrees C for D. viridis (108 n mol O(2)microg chl alpha h(-1)) and D. salina (139 n mol O(2)microg chl alpha h(-1)). Photosynthetic responses to temperature variations indicated physiological adjustments in both species, with higher acclimation in D. salina. Evaluation of physiological attributes of these species will be used for to carry out mass cultivation.
authors.affiliation: Department of Marine Resources, Cinvestav, Km 6 carretera antigua a Progreso, Cordemex 97310, AP 73 Mérida, Yucatan, Mexico.
authors.forename: Francisca
authors.initials: F
authors.lastname: García
authors.forename: Yolanda
authors.initials: Y
authors.lastname: Freile-Pelegrín
authors.forename: Daniel
authors.initials: D
authors.lastname: Robledo
mesh_terms: D000704:Analysis of Variance; D002338:Carotenoids / Q000032:analysis; D000460:Chlorophyta / Q000737:chemistry* / Q000254:growth & development*; D008800:Mexico; D010788:Photosynthesis / Q000502:physiology*; D013045:Species Specificity; D013696:Temperature
chemical_list: D002338:Carotenoids