ISSN 2756-3413
African Journal of Virology Research ISSN 3421-7347 Vol. 3 (3), pp. 001-010, March, 2009. © International Scholars Journals
Full Length Research Paper
Antifungal activity and bioactive compounds produced by Bacillus mojavensis and Bacillus subtilis
Mounia YOUCEF-ALI1*, Noreddine KACEM CHAOUCHE1, Laid DEHIMAT1, Insaf BATAICHE1, Mounira KARA ALI1, Hélène CAWOY2 and Philippe THONART2
1Laboratory of Mycology, Biotechnology and Microbial activity, FSNV, University Constantine-1 Constantine, 25000 Algeria. *E-mail: [email protected]
2Walloon Centre for Industrial Biology, Agro-Bio Tech, University of Liege Gembloux, 5030 Belgium.
Accepted 20 January, 2007
Abstract
The soil bacteria, CWBI-B1567 and CWBI-B1568, isolated from arid regions and identified as Bacillus subtilis (accession number KC341751) and Bacillus mojavensis (accession number KC341749) respectively, were screened and evaluated for their antifungal activity against Candida albicans, one of the most important human fungal pathogens. In vitro assay with the antagonists and their cell-free culture supernatants on agar plates showed that the two Bacillus strains effectively inhibited growth of the yeast. The capacity of these Bacillus strains to produce the cell-wall degrading enzymes was further studied. B. subtilis and B. mojavensis are able to produce cellulase and protease, but not chitinase. Bioactive molecules were produced by B. subtilis CWBI-B1567 and B. mojavensis CWBI-B1568 in a liquid culture medium optimised for lipopeptide production. The antifungal activity was equally demonstrated by testing the resulting supernatants and lipopeptide-enriched extracts. The electro-spray mass spectrometry coupled to liquid chromatography (ESI-LC-MS) analysis showed that both the B. subtilis and the B. mojavensis produced surfactin and iturin. However the fengycin group was produced only by B. mojavensis. Through this study, we have demonstrated that B. subtilis and B. mojavensis have a strong antifungal activity especially against C. albicans. This growth inhibition is probably due to the production of cell-wall degrading enzymes and different families of lipopeptide including iturins, fengycins and surfactins.
Key words: Bacillus subtilis CWBI-B1567, Bacillus mojavensis CWBI-B1568, antifungal activity, Candida albicans, lipopeptides, electro-spray mass spectrometry coupled to liquid chromatography (ESI-LC-MS), arid regions.