ISSN 2329-9835
International Journal of Diseases and Disorders ISSN 2329-9835 Vol. 6 (1), pp. 001-011, January, 2018. © International Scholars Journals
Full Length Research Paper
Identification and partial characterization of antifungal and antibacterial activities of two Bacillus sp. strains isolated from salt soil in Tunisia
Sihem Ben Maachia1,2,3*, Rafik Errakhi1, Florence Mathieu1, Mohamed Chérif3 and Ahmed Lebrihi1
1Laboratoire de Génie chimique UMR 5503 (CNRS/INPT/UPS), Institut National Polytechnique de Toulouse, 1, Av. de l’Agrobiopole, 31326 Castanet-Tolozan, France.
2Centre Régional des Recherches en Agriculture Oasienne, Dégache, Tozeur, Tunisia.
3Laboratoire de Phytopathologie, Institut National Agronomique de Tunisie, Tunis, Tunisia.
Accepted 10 May, 2017
Abstract
Two Bacillus sp. strains (B29 and B27) isolated from soil in the South of Tunisia were tested for their abilities to produce antimicrobial compounds. Both strains showed antimicrobial activity against Gram-positive and Gram-negative bacteria, yeasts and fungi. The produced compounds were extracted by using four different solvents. The hexane extract allowed to obtain maximum of activity of the strain B29. The activity of the strain B27 was not elucidated by the four solvents used. Bio-autography results of B29 hexane extract revealed presence of different antibiotics and antifungal compounds with different Rf values of 0.3 and 0.76 for antifungal compounds and of 0.12, 0.14, 0.19 and 0.3 for antibiotics. Two active fractions were isolated from the culture broth of the strain B29 using semi-preparative HPLC. Partial sequencing of the 16S RDNA gene was used to identify both of Bacillus strains. They may be assigned to new Bacillus species.
Key words: Antimicrobial activity, Bacillus sp., characterization, salt soil, Tunisia.