Bacillus subtilis BS 107 as an antagonist of potato blackleg and soft rot bacteria

• Published in: Canadian journal of microbiology Vol. 44; no. 8; pp. 777 - 783
• Main Authors: Sharga, B.M, Lyon, G.D
• Format: Journal Article
• Language: English
• Published: Ottawa, ON National Research Council of Canada 01.08.1998; Canadian Science Publishing NRC Research Press
• Subjects: Anti-Bacterial Agents - biosynthesis; Anti-Bacterial Agents - isolation & purification; Anti-Bacterial Agents - pharmacology; Antibiotics; Bacillus subtilis; Bacillus subtilis - physiology; Bacillus subtilis - ultrastructure; Bacteria; Bacteria - drug effects; Bacterial plant pathogens; Biological and medical sciences; biological control; Diseases & pests; Ethanol; Filtrate; Fundamental and applied biological sciences. Psychology; Generalities. Techniques. Transmission, epidemiology, ecology. Antibacterial substances, control; Microbiology; Microscopy, Electron, Scanning; Pectobacterium carotovorum - drug effects; Pectobacterium carotovorum - pathogenicity; Pectobacterium carotovorum - ultrastructure; Pectobacterium carotovorum subsp. atrosepticum; Pectobacterium carotovorum subsp. carotovorum; Phytopathology. Animal pests. Plant and forest protection; Plant Diseases - microbiology; Potatoes; R&D; Research & development; Silica; Solanum tuberosum; Solanum tuberosum - microbiology; Thin layer chromatography; Plant pathogen; Bacillus subtilis; Solanum tuberosum; Biological control; Bacillaceae; Biological activity; Erwinia carotovora; Antagonism; Antibiotic; Bacillales; Dicotyledones; Angiospermae; Bacteria; Spermatophyta; Tuber plant; Solanaceae; Activity spectrum; Mechanism of action; Enterobacteriaceae
• ISSN: 0008-4166; 1480-3275
• DOI: 10.1139/cjm-44-8-777

Antimicrobial substances were produced by Bacillus subtilis BS 107 in a defined medium and isolated from culture filtrate by precipitation at pH 2.5. Active fractions were extracted in ethyl acetate, acetone, and 80% ethanol and purified by thin-layer chromatography (TLC) on silica gel plates developed with an ethanol-water mixture (2:1, v/v). In each case, a band with a Rf of 0.75 formed an inhibitory zone when the TLC plates were placed in contact with agar seeded with test cultures of the Erwinia spp. The antibiotic was released into the culture medium during early stages of growth of Bacillus subtilis BS 107 but higher amounts were released in older cultures. The antibiotic was resistant to the action of nucleases, proteases, and lipase. It was stable when autoclaved twice for 35 min at 2 atm (1 atm = 101.325 kPa) in acidic, neutral, and alkaline solutions. It remained active over the pH range of 1-14 during 1 month of observation and exhibited no loss of antimicrobial activity when stored at 4 degrees C for over 1 year. Bacillus subtilis BS 107 showed activity in vitro and in vivo against Erwinia carotovora subsp. atroseptica and Erwinia carotovora subsp. carotovora, the causal agents of potato blackleg and tuber soft rot. The application of an antagonist or its antibiotic to cut potato tissues prevented or reduced symptoms of the diseases. The antibiotic was active in vitro against a broad spectrum of bacterial and fungal species.