Hiệu quả phòng trừ sinh học bệnh hoại tử gan tụy cấp tính (AHPND) gây ra bởi <i>Vibrio parahaemolyticus</i> NT2.5 trên tôm thẻ từ in vitro tới quy mô nuôi thương phẩm của chế phẩm vi sinh CPVS 01 và CPVS 02

Abstract

     In this study, by using perpendicular streak method and disk diffusion method, we determined Bacillus polyfermenticus F₂₇ has ability to resist V. parahaemolyticus NT_2.5, with the largest circular ring of diameter 18,50 mm. The ability of biological control to V. parahaemolyticus NT_2.5 of B. polyfermenticus F₂₇ have been proved in 25 liters tank experiment, with 10⁶ CFU/ mL, 10⁷ CFU/ mL, the survival rate (%) of shrimp are 75.55 ± 3.85 % and 82.22 ± 3.85 %, RPS protection rate (%) are 73.17 % and 80.49 %, respectively. The CPVS 01 probiotic is used to mix with shrimp feed to inhibit V. parahaemolyticus in the shrimp’s intestinal tract, CPVS 02 is used to treat shrimp culture water to inhibit V. parahaemolyticus in ponds, its were researched and manufactured. In 1,5 m³ composite tank experiment, the result of the ability of biocontrol V. parahaemolyticus NT_2.5 causing AHPND of 2 types of probiotics with 10⁶ CFU/ mL, 10⁷ CFU/ mL density, the survival rate (%) of shrimp are 78.17 ± 3.79 %, 84.33 ± 2.75 %, RPS protection rate (%) are 77.61 %, 83.93 %, respectively. In the commercial scale shrimp farming, although 9C pond is positive with AHPND from 50th day, shrimp ate and grown normally, there was no sign of mass death of AHPND. The results of this study showed that the CPVS 01 and CPVS 02 probiotics have potential application to biocontrol AHPND in commercial scale shrimp farming.