دارا باقری

The present study aimed to investigate the effects of two probiotics, namely Bacillus subtilis (ATCC 6633) and Lactobacillus plantarum (RITCC 1273), on the postlarvae of Litopenaeus vannamei (between 0.5 and 1.5 g). Different combinations of B. subtilis and L. plantarum in two concentrations of B. subtilis (B1 (106 CFU.mL􀀀 1) and B2 (3 ×106 CFU.mL􀀀 1)) and two concentrations of L. plantarum (L1 (105 CFU.mL􀀀 1) and L2 (3 ×105 CFU.mL􀀀 1)), were added to the water in five treatment groups (T1 = L1 × B2, T2 = L1 × B1, T3 = L2 × B2, T4 = L2 × B1, and Control). The objective was to assess probiotics’ impact on hemolymph indices, salinity stress, growth rate, and productive parameters of Litopenaeus vannamei. After farming shrimps for 60 days under modified conditions using probiotics, the shrimps were harvested and transferred to store at 􀀀 18 ℃ for 60 days, and the effects of probiotics on the shelf-life of shrimps under freezing preservation were determined. Nutritional values, pH, Thiobarbituric acid reactive substances (TBARS), Total volatile nitrogen determination (TVB-N), Water holding capacity (WHC), drip loss, and texture profile were assessed. The results indicated that water quality remained relatively stable throughout the aquaculture phase, with no significant (P > 0.05) alterations observed in pH, ammonia nitrogen, nitrate-nitrogen, and nitrite-nitrogen levels. The growth performance tests revealed that treatment T1 (L1 × B2) exhibited the highest weight gain (WG), survival rate (SR), specific growth rate (SGR), and relative feed conversion efficiency (RFC). Conversely, T4 (L2 × B1) displayed significantly lower levels of triglycerides (274.51 ± 17 mg/dL) and higher levels of cholesterol (3581.61 ± 1222 mg/dL). Regarding shrimp storage, T4 demonstrated the best performance with the highest WHC (31.9 ± 7.8%) and lowest drip loss (4.7 ± 0.4%) among the treatments on day 60.