Abstract
The ability of sludge, lignin and humic acid to support the growth and production of antimicrobial substances by 19 microorganism strains was tested. Organisms from seven genera: Bacillus, Pseudomonas, Streptomyces, Beauveria, Paecilomyces, Trichoderma and Trichosporon grew on the tested media. On these media, they were also examined for the production of anti-phytopathogenic activity against Fusarium oxysporum P1 BIM, Botrytis cinerea B1 BIM and Pseudomonas syringae. pv. glicinea B-280 BIM. Strains Pseudomonas aurantiaca S-1, Bacillus sp. 19 and Streptomyces sp. 11 synthesize antimicrobial metabolites on the different media. Protease, cellulase, α-amylase, xylanase and peroxidase were also produced by the same microorganisms, which can explain their ability to grow on sludge, and laccase was produced only by P. aurantiaca S-1. HPLC analysis of the lignin culture media before and after P. aurantiaca S-1 growth has shown that the major lignin peak in the culture broth disappeared.
Acknowledgements
This study was supported by a grant from the Projects and Network Co-operation within the Visby Programme University Co-operation with Central-Eastern Europe.
We are grateful to Simon Gough for critical reading of the manuscript.