Pyrrolnitrin production by biological control agent Pseudomonas cepacia B37w in culture and in colonized wounds of potatoes

• Published in: Applied and Environmental Microbiology Vol. 60; no. 6; pp. 2031 - 2039
• Main Authors: BURKHEAD, K. D, SCHISLER, D. A, SLININGER, P. J
• Format: Journal Article
• Language: English
• Published: Washington, DC American Society for Microbiology 01.06.1994
• Subjects: Agronomy. Soil science and plant productions; antibioticos; antibiotics; Antibiotics (antibacterial agents, antifungal agents); Antibiotics, microbial producers, chemotherapic agents, antiseptics, disinfecting agents; antibiotique; antifungal properties; Applied microbiology; Bacteria; Biochemistry; biodeterioration; biodeterioro; Biological and medical sciences; Biological control; Biology of microorganisms of confirmed or potential industrial interest; Biotechnology; Control; fongicide; Fundamental and applied biological sciences. Psychology; Fungal plant pathogens; Fungi; fungicidas; fungicides; Fusarium sambucinum; gibberella; microbial pesticides; Microbiology; Microorganism-Plant Interactions; Miscellaneous; Mission oriented research; papa; perdidas postcosecha; perte apres recolte; pesticide microbien; Phytopathology. Animal pests. Plant and forest protection; plaguicidas microbianos; pomme de terre; postharvest losses; Potatoes; propiedades antimicosicas; propriete antifongique; Pseudomonas cepacia; Solanum tuberosum; Pseudomonadales; Plant pathogen; Solanum tuberosum; Biological control; Colletotrichum truncatum; Biological activity; Fungi; Antibiotic; Antifungal agent; Pseudomonas cepacia; Dicotyledones; Angiospermae; Production; Bacteria; Pseudomonadaceae; Spermatophyta; Fungi Imperfecti; Solanaceae; Fusarium sambucinum; Tuber plant; Mechanism of action; Thallophyta
• ISSN: 0099-2240; 1098-5336
• DOI: 10.1128/AEM.60.6.2031-2039.1994

Bacterial strain B37w (= NRRL B-14858), an isolate noteworthy because it inhibits the growth of the bioherbicide fungus Colletotrichum truncatum, was selected for further studies of bacterial antifungal properties. This isolate was identified as a Pseudomonas cepacia strain by performing carbohydrate utilization and fatty acid profile analyses, as well as other biochemical and physiological tests. Petri plate assays revealed that strain B37w exhibited antifungal activity against the potato dry rot fungus Fusarium sambucinum. Using bioautography, we correlated antifungal activity with production of a specific compound. Isolation from strain B37w and identification of the antifungal antibiotic pyrrolnitrin are described. A whole-potato assay revealed B37w's ability to colonize potato wounds. Wounded potatoes were inoculated with B37w, and pyrrolnitrin was detected in these potatoes by thin-layer chromatography-bioautography at a concentration on the order of nanograms per wound. We performed an assay in which we examined efficacy against F. sambucinum-incited potato dry rot and found that B37w inhibited disease development. This is the first report of P. cepacia or pyrrolnitrin activity against the economically important potato pathogen F. sambucinum.