The Effectiveness of Lactic Acid Bacteria on the Immune System of Vannamei Shrimp Infected with Bacteria Vibrio Parahaemolyticus

Abstract

Diseases are a major obstacle in shrimp farming because they can cause relatively high mortality and decrease the quality of the aquaculture environment. One dangerous shrimp disease is caused by Vibrio bacteria. Today, people are turning to biological control methods by utilizing lactic acid bacteria that live as microflora in the digestive tract of aquaculture animals. This study aimed to analyze the potential of lactic acid bacteria isolates from the gut of vannamei shrimp as probiotic candidates and to analyze selected lactic acid bacteria isolates that were effective in increasing the immune response and survival of vannamei shrimp infected with Vibrio parahaemolyticus bacteria. Four BAL isolates were isolated, designated as 8A, 11B, F1, and G2. BAL isolates showed antibacterial activity against Vibrio parahaemolyticus bacteria with an inhibition zone of up to 11.5 mm, capable of living at acidic to alkaline pH (1.5-7.2), bile salts (3000 ppm) and negative catalase. The characterization of several tests such as gram-positive, inhibition test and sugar fermentation test and comparison of LAB characterization showed that LAB isolates (G2) from the intestine of vannamei shrimp were classified as Pediococcus acidilactici. The application of probiotics, namely LAB (G2) to vannamei shrimp through feed can stimulate the vaname shrimp immune system after being challenged with V. parahaemolyticus, as indicated by an increase in the number of hemocytes (THC), phagocytosis activity, and suppressing the population of V. parahaemolyticus in vannamei shrimp.