The Stability of Immunoglobulin Y (IgY) against Streptococcal Infection in Tilapia Aquaculture Environment for the Development of Prophylactic and Therapeutic Agents

Abstract

Immunoglobulin Y (IgY) can be used as a prophylactic and therapeutic agent for streptococcal infection in tilapia. This study explores the stability of IgY against water salinity and pH, temperature, and the presence of protease, which all stimulate the conditions of the digestive tract of tilapia. It was found that water salinity and pH levels of 0, 15, and 30 ppt as well as 6.5, 7.5, and 8.5 respectively, with an incubation period of six days, and temperatures of 25, 45, and 60 °C for 60 minutes did not affect the molecular weight of IgY and resulted in positive ELISA test results. Extreme conditions at 80 °C and incubation with the pepsin showed negative results in the ELISA test starting at minute 40. However, from its incubation at 80 °C, IgY did not show any change in its molecular weight, as shown in the SDS PAGE gel. Trypsin also did not affect the molecular weight characteristics of IgY and showed a positive result in the ELISA test. However, IgY could not be detected after its treatment with pepsin. Based on this study, it can be concluded that IgY could lose its biological function due to heating to 80 °C and exposure to pepsin. However, IgY is resistant to the trypsin, water salinity, and pH levels in tilapia aquaculture.