Comparison of growth and biochemical parameters of two strains of Rhodomonas salina (Cryptophyceae) cultivated under different combinations of irradiance, temperature, and nutrients Miguel Guevara 1 & Bertha O. Arredondo-Vega 2 & Yussi Palacios 3 & Katia Saéz 4 & Patricia I. Gómez 5 Received: 2 September 2015 /Revised and accepted: 13 March 2016 # Springer Science+Business Media Dordrecht 2016 Abstract Growth and biochemical parameters of two strains of Rhodomonas salina (Cryptophyceae), cultivated under dif- ferent combinations of irradiance, temperature, and nutrients, were compared. The microalgae were grown in batch mode for 10 days, in f/2 medium at 33‰ salinity. The experimental design was a 2 5 factorial design with the following variables: nitrate [0.441 mM (N1) and 3.529 mM (N2)], phosphate [0.018 mM (P1) and 0.144 mM (P2)], temperature [19 and 29 °C], continued irradiance [100 μmol photons m -2 s -1 (low light, LL), and 200 μmol photons m -2 s -1 (high light, HL)] and microalgae strains (CS-174 and CS-24). Growth parame- ters, protein and lipid content, and fatty acids profiles were analyzed. Principal component analysis showed that com- bined high nitrate, high phosphate availability, and high light, regardless of temperature, achieved the best growth in both strains; while combined high nitrate and high phosphate, re- gardless of irradiance or temperature, resulted in the highest protein accumulation in both strains. On the other hand, the content of total lipid, arachidonic (ARA), eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids, as well as EPA/ DHA ratio, were strongly influenced by temperature in both strains. Strain CS-174 grew better and achieved significantly higher (p < 0.05) total lipid content (maximum 25.4± 1.5 %), ARA, EPA and DHA content (maximum 3.5, 13.2 and 6.5 %, respectively), and EPA / DHA ratio (maximum 2.03), than strain CS-24, being thus more suitable for use in aquaculture nutrition. Keywords Cryptophyta . Rhodomonas salina strains . Nutritional value . Aquaculture Introduction Microalgae are the primary source of nutrition for all devel- opment stages of filter-feeder bivalves, larval and juvenile stages of some fish and crustacean species, and to enrich live prey (e.g. copepods, rotifers) for rearing several marine spe- cies (Brown et al. 1997; Borowitzka 1997; Reitan et al. 1997; Renaud et al. 1999). The nutritional quality of microalgae of interest for aqua- culture and biotechnology can be improved by optimizing culture conditions, such as temperature, irradiance, and/or the culture medium (e.g. Richmond 1986; Sukenik et al. 1989; Fidalgo et al. 1995; Brown et al. 1997; Renaud et al. 2002). However, it is important to note that the response of microalgae to variations in abiotic factors varies from species to species, but also between strains belonging to the same species (Shaw et al. 1989; López-Alonso et al. 1992a, b, 1994; Gómez and González 2005) and even between clones Electronic supplementary material The online version of this article (doi:10.1007/s10811-016-0835-2) contains supplementary material, which is available to authorized users. * Patricia I. Gómez pgomez@udec.cl 1 Instituto Oceanográfico de Venezuela, Departamento de Biología Pesquera, Universidad de Oriente, Oriente 6101, Venezuela 2 Centro de Investigaciones Biológicas del Noroeste, S. C., CIBNOR, Col. Playa Palo de Santa Rita, C.P. 23090, La Paz, Baja California Sur, Mexico 3 School of Biological Sciences, Monash University, Clayton campus, Melbourne 3800, Australia 4 Departamento de Estadística, Facultad de Ciencias Físicas y Matemáticas, Universidad de Concepción, Concepción, Chile 5 Grupo de Investigación Microalgal FICOLAB, Departamento de Botánica, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, Casilla 160-C, Concepción, Chile J Appl Phycol DOI 10.1007/s10811-016-0835-2