Genome-wide Prediction and Functional Analysis of Secretory Protein of Pseudomonas fluorescens from Fish

Objective: Pseudomonas fluorescens is a dominant spoilage bacterium in refrigerated Marine fish. Its strong ability of extracellular protein secretion is one of the important factors leading to fish spoilage. Thus， extracellular protein composition and secretion pathway under the whole genome level of P. fluorescens from fish are explored. Methods: A variety of bioinformatics analysis software was used to predict the extracellular protein secretion of P. fluorescens PF08 from fish and to analyze its function. Results: In the 5 514 proteins encoded by P. fluorescens PF08 in the whole genome，sixty-six classical secreted proteins with Sec/SPI type signal peptides， localized extracellular，with none or only one transmembrane structure and no GPI anchor site were screened. Most proteins were 101-400 amino acids， small molecular proteins， and the proportion of hydrophobic amino acids was the highest. 13 pili proteins， 11 enzymes， 2 flagellins， 7 DUFs family proteins， 17 unknown functional hypothesized proteins and 16 other functional proteins were annotated by Nr database. Further through COG analysis， these proteins were mainly annotated into the functional categories of intracellular transport， secretion and vesicle transport， cell motility， signal transduction and cell wall，membrane and biological envelope. GO annotation showed that these proteins were highly annotated in the three categories of biological processes， cell components and molecular functions. Conclusion: The secretory proteome of P. fluorescens consisted of different functional and properties proteins，involving key proteins that promote the extracellular colonization， biofilm formation， decomposition of food components， etc. It provides an important basis for further research on the spoilage mechanisms of P. fluorescens in fish. © 2024 Chinese Institute of Food Science and Technology. All rights reserved.