Identification and Characterization of a Proteinaceous Antibacterial Factor from Pseudomonas extremorientalis PEY1 Active Against Edwardsiella tarda
Year: 2025
Type: article
Abstract: Pseudomonas extremorientalis PEY1, isolated from the intestinal contents of marine fish, was evaluated for the production and properties of antibacterial proteins active against Edwardsiella tarda, a major pathogen in aquaculture. Antibacterial production was maximized in a minimal medium supplemented with 1% yeast extract and 1% galactose under stationary cultivation at 25 °C and pH 7.0. Growth and bioactivity assays were conducted under varying carbon and nitrogen sources, temperatures, and pH levels. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis revealed a distinct ~37 kDa protein band corresponding to antibacterial activity, exhibiting an inhibition zone of 2.4 ± 0.1 cm against E. tarda. The activity was completely abolished by papain digestion but remained detectable after exposure to 55 °C and pH 8, indicating that the active compound is a moderately heat-stable, proteinaceous antibacterial molecule. LC–MS/MS analysis identified the protein as a putative disulfide reductase with ~40% sequence coverage. The antibacterial factor exhibited strong physicochemical stability, retaining activity in the presence of surfactants and metal ions. Collectively, these findings demonstrate that P. extremorientalis PEY1 produces a thermostable, papain-sensitive antibacterial protein with selective activity against E. tarda, highlighting its potential as a promising natural biocontrol or postbiotic candidate for sustainable aquaculture.
Source: Microbiology Research
Authors: Hyun-Sol Jo, Youl-Lae Jo, Sun-Mee Hong
Institutions: Korea Food Research Institute, Yeungnam University
Language: English
Subfield: Immunology
Field: Immunology and Microbiology
Domain: Life Sciences
Open Access status: gold
Estimated APC paid: $1,930
OpenAlex ID: W7117697573