Control of Vibrio sp. using calcium hidroxide in pond of shrimp (Litopenaeus vannamei) culture in Santa Catarina

Abstract

Bacterial diseases, mainly those caused by bacteria of the Vibrio genus, are responsible for significant economic losses in the shrimp production. This study aimed to verify the concentration of calcium hydroxide [Ca(OH)₂] able to inhibit growth of Vibrio harveyi in vitro, and also to test in vivo its use in culture ponds. For the in vitro experiment, bottles were used with BHI culture medium (Brain Heart Infusion) supplemented with Ca(OH)₂ in four different concentrations (0; 0.018 g/L; 0.025 g/L and 0.036 g/L), inoculated with 1.2 x 10¹¹ CFU/mL and incubated for 24 h under continuous agitation. The bacterial growth in the treatments was estimated by total counting of colonies in plates by successive dilutions (1/10). For the experiment in culture ponds, calcium hydroxide in the concentration of 0.018 g/L was applied for three consecutive days. Total counting of colonies in Marine Agar and TCBS (Thiosulphate-Citrate-Bile Salts-Sucrose) plates was done before and 48 h after calcium hydroxide application. The Vibrio concentration decreased significantly after the application, from 4.36 ± 0.1 (log UFC/mL ± DP) to 3.07 ± 0.36 (log UFC/mL ± DP). However, significant decrease in the concentration of total bacteria was not observed. In this way, it was evidenced that Ca(OH)₂ can be used in the control of Vibrio spp. in rearing systems.