The absence of new antibiotics is guiding more and more researchers to specific ecosystems. One hundred and sixty-three Actinobacteria isolates were isolated from Merzouga sand and screened for their antibacterial and antifungal activities. To test the antimicrobial effect of isolates, four microorganisms known as human potential pathogens were used. The electrophoretic profiles of isolates obtained by repetitive element PCR fingerprinting (rep-PCR) were compared by clustering. Results showed that among the tested isolates, 59% were active against one or more in testing Gram-positive, Gram-negative and the yeast Candida albicans. The importance of culture media for the activity expression was revealed. Comparative analysis of antimicrobial activity divided isolates into 15 groups. The comparison of the average diameters of inhibition zones using Minitab V.17 allowed subdivision of the 15 groups into 20 subgroups. Dendrograms derived from the BOXA1R-PCR fingerprints showed that 36 isolates were grouped in 16 clusters, containing from two to four isolates while 127 isolates were not grouped. The tested antimicrobial activities showed a high biological diversity with important inhibition of pathogens tested. The rep-PCR revealed a high taxonomic diversity of isolates. The combination of antimicrobial activity and rep-PCR results revealed the diverse pattern of Merzouga sand dune Actinobacteria.

This study reported the volatile profile, the antimicrobial activity and the synergistic potential of essential oil (EO) from the Moroccan endemic Thymus atlanticus (Ball) Roussine, in combination with the antibiotics ciprofloxacin and fluconazole for the first time, to the best of our knowledge. The EO chemical composition was determined by gas chromatography coupled to mass spectrometry (GC-MS) analysis and the antimicrobial activity assessed by the disc diffusion method against three Gram positive (Bacillus subtilis, Micrococcus luteus, Staphylococcus aureus) and three Gram-negative bacteria (Pseudomonas aeruginosa, Escherichia coli and one clinical isolate, Klebsiella pneumonia). The antifungal activity was evaluated in four pathogenic yeasts (Candida albicans, C. glabrata, C. krusei and C. parapsilosis). The minimum inhibition concentration (MIC) and the synergistic effect with ciprofloxacin and fluconazole were determined by the two-fold dilution technique and checkerboard test, respectively. Twenty-one constituents were identified by GC-MS in the EO, including carvacrol (21.62%) and borneol (21.13%) as the major components. The EO exhibited a significant antimicrobial activity with inhibition zones ranging from 0.7 mm to 22 mm for P. aeruginosa and B. subtilis, respectively, and MIC values varying from 0.56 mg/mL to 4.47 mg/mL. The fractional inhibitory concentration index (FICI) values ranged from 0.25 to 0.50 for bacteria and from 0.25 to 0.28 for yeasts. The maximum synergistic effect was observed for K. pneumonia with a 256-fold gain of antibiotic MIC. Our results have suggested that EO from T. atlanticus may be used alone or in association with antibiotics as a new potential alternative to prevent and control the emergence of resistant microbial strains both in the medical field and in the food industry.

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Lawsonia inermis, commonly known as Henna, is a plant that has been extensively utilized throughout the ages for its medicinal and cosmetic properties. This plant contains a variety of bioactive compounds and has attracted significant interest due to its potential antioxidant and antimicrobial activities. The aim of our study is to evaluate the antioxidant capacity and antibacterial activity of Lawsonia inermis seeds. L. inermis seed powder was extracted using hexane, dichloromethane, ethanol and water. The 4 fractions were quantified for polyphenols, flavonoids and tannins contents. The antioxidant capacity was assessed using 4 methods: 2,2?-Diphenyl- picrylhydrazyl hydrate (DPPH) , 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic) (ABTS), Ferric Reducing Antioxidant Power (FRAP), and Phosphomolybdate assay (PMA). Antimicrobial activity was determined by agar diffusion against Staphylococcus aureus, Bacillus cereus, Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa and Candida albicans. The liquid dilution method was used to determine the minimum inhibitory concentration, minimum bactericidal concentration and minimum fungicidal concentration. The highest content of polyphenols and tannins was obtained in the ethanolic fraction, with values of 594.01±6.07 mg GAE/g dw and 242.4±1.6 mg CE/g dw respectively. The ethanolic fraction exhibited significant scavenging of free radicals (DPPH) with an IC50 of 3.06±0.01 µg/mL, lower than the IC50 of the standard quercetin (5.30±0.02 µg/mL). Moreover, the ethanolic fraction showed antimicrobial activity against S. aureus, B. cereus and E. faecalis strains, with zone of inhibition values of 15.5±0.7, 14.0±0.0 and 14.5±0.7 mm respectively. The minimum inhibitory concentration of the ethanolic fraction was found to be 1.563 mg/mL against both S. aureus and B. cereus strains, while the minimum bactericidal concentration was 3.125 mg/mL against B. cereus and 6.25 mg/mL against E. faecalis strains. L. inermis seeds exhibit significant antioxidant capacity and demonstrate antimicrobial activity. These findings indicate the potential of L. inermis seeds as a valuable source of bioactive compounds with antioxidant and antimicrobial properties.

Microbial volatile organic compounds have been shown to affect a wide insect behavior. In this paper, we report the draft genome sequence of Bacillus licheniformis strain Ba1 previously isolated from desert soil in Morocco. The assembled and annotated draft genome contains 4,726 coding genes, 6 rRNAs and 97 tRNAs.