Isolation and Molecular Identification of Pathogenic Bacteria in Giant Gourami (Osphronemus gouramy) Cultivated in Tamansari and Singasari Villages, Banyumas Regency

Abstract

Giant gourami (Osphronemus gouramy) is a freshwater fishery commodity with high economic value and is widely cultivated in Banyumas Regency. However, the emergence of diseases caused by pathogenic bacteria often becomes an obstacle in cultivation activities because it can reduce the survival rate and productivity of fish. This study aims to identify the types of pathogenic bacteria found in gouramy fish raised in Tamansari and Singasari Villages, Banyumas Regency. The research method was carried out by taking liver samples of gouramy fish which were then isolated on TSA media. Identification was carried out based on the morphological characteristics of bacterial colonies, the Gram KOH test, and molecular identification. The results showed that from both locations, several bacterial isolates were obtained with similar colony morphological characteristics, namely round (circular), small size, smooth edges, smooth surface, and cream color. The results of the Gram KOH test showed that all isolates were Gram-negative bacteria. Based on these characteristics, the isolates have similarities with the genus Acinetobacter which is often found as an opportunistic bacteria in freshwater fish. The results of molecular identification also showed that the bacteria obtained from the cultivated gouramy fish were Acinetobacter sp. This study provides a preliminary overview of the presence of opportunistic bacteria such as Acinetobacter sp., which have the potential to become pathogens in gourami when water quality conditions are unstable.