Antifungal activity of Streptomyces sp.14 strain isolated from Ouargla (Southeast of Algeria): identification, production and characterization of the active substance
By: Sabrina Bouaziz, Abdelaziz Messis, Azzeddine Bettache, Mohammed Didi Oueld El Hadj, Et Said Benallaoua
Key Words: Antifungal activity, Sahara soil, Streptomyces, Production kinetics
Int. J. Biosci. 9(5), 45-56, November 2016.
This work aims to study the antifungal activity of strain encoded I4. The strain was isolated from Saharan soil of Ouargla region (Southeast of Algeria). The identification of the isolate I4 was carried out on the basis of morphological, biochemical and physiological criteria whose taxonomy suggested that this isolate belonged to Streptomyces genus. The antifungal activity by the agar cylinder method on solid medium revealed that isolate I4 showed strong activity against various pathogenic fungi as well as gram-positive and gram-negative bacteria, hence the best activity observed against Aspergillus niger2CA936 with an inhibition zone of 30 mm in diameter. The production kinetics of the antibiotic ware made on M2 liquid medium. The optimal activity was achieved at the end of exponential growth phase and beginning of decline phase, in the fifth day of incubation. The antibiotics secreted by the strain I4 were hydrophobic, and more extractable by apolar solvents, it were revealed by bioautography and chemical development. The result obtained showed the presence of a single active zone, chemical developers suggested that the active molecule contains carbohydrate residues not of polyenic nature.