en Other Other Original Article Original Article <p style="text-align: justify;">Extreme ecosystems can be a source of untapped micro-organisms able to produce novel bioactive compounds of industrial interest. Consequently, in this work, 32 Actinomycetes were isolated from 6 soil samples collected from Algerian Sahara in searching for untapped producers of novel antimicrobial compounds. All the isolates were further subjected to antimicrobial screening against pathogenic bacteria, yeast and fungi. The obtained results indicated that three of the isolates (named C, MS1 and 10) showed antimicrobial activities against most of the tested pathogenic micro-organisms. Therefore, these three promising isolates, previously identified as <em>Streptomyces</em> by morphological, biochemical and physiological methods, were selected for their subsequent identification by the whole cell matrix assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS) analysis. Thus, the isolates C, MS1 and 10 were identified as <em>Streptomyces violaceoruber</em> B263 UFL, <em>Streptomyces albus</em> B262 UFL, and <em>Streptomyces badius</em> B192 UFL, respectively. These results pointed out Actinomycetes from Sahara soils as potential sources of novel antimicrobial compounds. Also, MALDI-TOF MS showed to be a robust technique for bacteria identification.</p> Actinobacteria, antimicrobial activities, MALDI-TOF MS, Sahara soils, strain identification 109 120 http://ijmcmed.org/browse.php?a_code=A-10-1135-1&slc_lang=en&sid=1 Harir Mohamed Mohamedharir57@yahoo.fr 10031947532846009347 10031947532846009347 No Biology of Microorganisms and Biotechnology Laboratory, University of Oran 1 Ahmed Ben Bella, Oran, Algeria. Bellahcene Miloud bellahcene_miloud@yahoo.fr 10031947532846009348 10031947532846009348 No Faculty of Sciences, Natural and Life Sciences Department, Mohamed Boudiaf University, M’sila, Algeria. Fortas Zohra torfez2000@yahoo.fr 10031947532846009349 10031947532846009349 No Biology of Microorganisms and Biotechnology Laboratory, University of Oran 1 Ahmed Ben Bella, Oran, Algeria. José María José María García-Arenzana arenzana@chdo.osakidetza.net 10031947532846009350 10031947532846009350 No Microbiología, Hospital Universitario Donostia, Donostia-San Sebastián, Spain. Antonio Veloso avelosofernandez@gmail.com 10031947532846009351 10031947532846009351 No POLYMAT, University of the Basque Country UPV/EHU, Donostia-San Sebastian, Spain. Susana Rodriguez-Couto srodriguez@ceiit.es 10031947532846009352 10031947532846009352 Yes Ceit-IK4, Water & Health Division, Donostia-San Sebastian, Spain.