Genome analysis of Pseudomonas strain 4B with broad antagonistic activity against toxigenic fungi

• Published in: Brazilian journal of microbiology Vol. 55; no. 1; pp. 269 - 280
• Main Authors: Veras, Flávio Fonseca, Stincone, Paolo, Welke, Juliane Elisa, Ritter, Ana Carolina, Siqueira, Franciele Maboni, Varela, Ana Paula Muterle, Mayer, Fabiana Quoos, Brandelli, Adriano
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01.03.2024; Springer Nature B.V
• Subjects: Abattoirs; Aflatoxin B1; Aflatoxins; Antifungal activity; Bacteria; Biomedical and Life Sciences; Biosynthesis; Biotechnology and Industrial Microbiology - Research Paper; Colonies; Food Microbiology; Fungi; Fungicides; Gene clusters; Genomes; Germination; Life Sciences; Medical Microbiology; Metabolites; Microbial Ecology; Microbial Genetics and Genomics; Microbiology; Mycology; Mycotoxins; Ochratoxin A; Phylogeny; Pseudomonas; Pseudomonas aeruginosa; Pyocyanin; Spore germination; Spores; Sporulation; Sucrose; Yeasts; Fungi; Genome; Pseudomonas
• ISSN: 1517-8382; 1678-4405; 1678-4405
• DOI: 10.1007/s42770-024-01253-w

Pseudomonas sp. 4B isolated from the effluent pond of a bovine abattoir was investigated as antifungal against toxigenic fungi. The complete genome of Pseudomonas 4B was sequenced using the Illumina MiSeq platform. Phylogenetic analysis and genome comparisons indicated that the strain belongs to the Pseudomonas aeruginosa group. In silico investigation revealed gene clusters associated with the biosynthesis of several antifungals, including pyocyanin, rhizomide, thanamycin, and pyochelin. This bacterium was investigated through antifungal assays, showing an inhibitory effect against all toxigenic fungi tested. Bacterial cells reduced the diameter of fungal colonies, colony growth rate, and sporulation of each indicator fungi in 10-day simultaneous growing tests. The co-incubation of bacterial suspension and fungal spores in yeast extract–sucrose broth for 48 h resulted in reduced spore germination. During simultaneous growth, decreased production of aflatoxin B1 and ochratoxin A by Aspergillus flavus and Aspergillus carbonarius , respectively, was observed. Genome analysis and in vitro studies showed the ability of P. aeruginosa 4B to reduce fungal growth parameters and mycotoxin levels, indicating the potential of this bacterium to control toxigenic fungi. The broad antifungal activity of this strain may represent a sustainable alternative for the exploration and subsequent use of its possible metabolites in order to control mycotoxin-producing fungi.