Effect of Debaryomyces hansenii on the antioxidant response of juvenile white shrimp Litopenaeus vannamei

Objective. To determine the antioxidant response [superoxide dismutase (SOD) and catalase (CAT) activity], as well as the total haemocyte count (CTH), and protein level (CP) in shrimp Litopenaeus vannamei exposed to different doses and yeast strains of Debaryomyces hansenii (DH5, DH6, LL1), and a commercial immunostimulant (LAM). Materials and methods. The yeast strains were cultured and administered daily directly into the shrimp tanks (8 +/- 0.2 g) in different concentrations (104 - 106 CFU/mL), while the LAM was administered weekly (0.5 mg/L). The organisms were kept under laboratory conditions (28 degrees C, 35 parts per thousand, 80% daily water exchange, commercial diet for shrimp fed ad libitum). Each treatment was twice distributed and the results were evaluated through variance analysis and the Tukey method. Results. A significant THC (p<0.05) was detected for the treatments with DH6 and LL1 (106 CFU / mL) compared to the control group, whereas strains DH5 and DH6 presented a significant increase (p<0.05) in the value of CP for the 104 CFU/mL dose. SOD and CAT values increased significantly (p<0.05) for shrimp exposed to LAM. Conclusions. The results of this study illustrate that D. hansenii increased the antioxidant response, and CTH of shrimp.