In addition, Schizochytrium S31 (ATCC 20888) was procured from American Type Culture Collection (ATCC) and used as standard culture. The isolates used in this study were maintained on GYP medium consisting (g L−1): glucose 5, yeast extract 2, mycological peptone 2, agar 10 and artificial seawater 50% at 25 °C and sub-cultured after 15 days