Marine bacterial activity against phytopathogenic Pseudomonas show high efficiency of Planctomycetes extracts

• Published in: European journal of plant pathology 2022-04, Vol.162 (4), p.843-854
• Main Authors: Gimranov, Emil, Santos, José D. N., Vitorino, Inês, Martín, Jesús, Reyes, Fernando, Moura, Luisa, Tavares, Fernando, Santos, Conceição, Mariz-Ponte, Nuno, Lage, Olga Maria
• Format: Article
• Language: English
• Subjects: Acetic acid; Actinobacteria; Agriculture; Agrochemicals; Antibiotics; Antimicrobial agents; Bacteria; Bioactive compounds; Biocompatibility; Biofilms; Biological activity; Biomedical and Life Sciences; Cereals; Ecology; Enzymes; Indoleacetic acid; Life Sciences; Liquid phases; Metabolites; Microorganisms; Orchards; Planctomycetes; Plant Pathology; Plant Sciences; Pseudomonas; R&D; Research & development; Secondary metabolites; Strains (organisms); Swimming; Tryptophan; Virulence
• ISSN: 0929-1873; 1573-8469
• DOI: 10.1007/s10658-021-02441-2

The genus Pseudomonas integrates several phytopathogenic species like P. syringae pv. syringae (Pss) and P. syringae pv. actinidae (Psa) and P viridiflava. Currently, effective treatments against these Pseudomonas phytopathogens are limited and mostly based on preventive measures or toxic agrochemicals, which pose risks of resistance-acquisition. Marine bacteria may represent new sources of sustainable bioactive compounds with use in agriculture. We assessed the anti-Pseudomonas activity of extracts from marine bacterial strains of seven genera of Actinobacteria and Planctomycetes. Pseudomonas strains were isolated from Portuguese orchards and included five Psa and one Pseudomonas sp. (B65). All the Pseudomonas strains used in this study shared common characteristics regarding swimming-motility, no biofilm-production in abiotic surfaces and production of indole-3-acetic acid (IAA) using a tryptophan-dependent pathway, showing the maintenance of virulence traits in culture. Four representative Pseudomonas strains were exposed to the marine Actinobacteria and Planctomycetes extracts obtained by liquid–liquid phase (LLPE). Only the planctomycetes Alienimonas chondri , Rhodopirellula rubra , Rubrinisphaera brasiliensis and Novipirellula caenicola inhibited Pseudomonas growth with percentages ranging from 56.48% to 83.08%. LC/HRMS dereplication of these bioactive extracts indicated the presence of several bioactive secondary metabolites like diketopiperazines, opening new perspectives for the use of these bacterial isolates and derived compounds in agriculture.