Bacillus subtilis produces various families of lipopeptides with different homologous compounds. To produce "new molecules" with improved activities and to select strains that produced a reduced number of homologs or isomers, we studied the effects of different media on the nature of the synthesis of fatty acid chains for each lipopeptide family. This study focused on two B. subtilis strains cultivated in flasks. Optimized medium for lipopeptide production and Landy medium modified by replacing glutamic acid with other alpha-amino acids were used. We found that the intensity of production of homologous compounds depends on the strain and the culture medium. Analysis of these lipopeptides by high-performance liquid chromatography showed that the strain B. subtilis NT02 yielded various homologous compounds when cultivated in Landy medium (L-Glu), but primarily one homologous product in high relative amounts when cultivated in the optimized medium. Mass spectrometric analysis and determination of the amino acid composition of this molecule enabled us to identify it as Bacillomycine L c15.

No abstract

Introduction: Campylobacter jejuni is one of the major causes of gastroenteritis worldwide of the last century. The aim of this study was to investigate the antibiotics profiles and the virulence gene in C. jejuni strains isolated from chicken in Côte d’Ivoire. Methodology: A total of 336 chicken ceaca samples recovered from market of two municipality of Abidjan were examined by conventional microbiological methods and molecular test using PCR. The antibiotic susceptibility tests of the isolates were determined by disk diffusion method. The presence of virulence genes was examined using simple PCR method. Results: Among of 336 samples, 168 (50%) were positives for C. jejuni. Among the C. jejuni isolates, 159 strains (94.64%) were resistant to one or more antimicrobial agents. The highest percentage of antimicrobial resistance was found for Nalidixic acid (85.33%), Tétracyclin (71.76%) and Ciprofloxacin (55.65%). Moreover, MDR including 3, 4, 5 and 6 antibiotics families was detected in 16.66% of isolates. On the other hand, detection of virulence putative gene shows presence of cadF in 100% of tested strains. In addition, cdtA, cdtB and cdtC genes were detected in 100%; 89.51% and 90.32% respectively of C. jejuniisolates. Conclusion: Because of the key role of broiler chicken in human campylobacteriosis infection, it will important in first time to monitoring using of antibiotics in chicken farms and in second time to verify presence of campylobactériosis in country.

No abstract

The aim of this work was to identify acetic acid bacteria expressing technological characteristics for further use in vinegar production in tropical countries. It was focused on isolation and identification of thermotolerant acetic acid bacteria strains from Elaeis guineensis wine of Côte d'Ivoire (Ivorian palm wine). A screening was performed to find out strains with high vinegar production, tolerant against high ethanol, acid and sugar concentrations as well as tolerating high production temperatures. Among 104 isolated strains, 5 were selected for their growth ability, acetification capacity (acetic acid production higher than 30 g/l) and suroxydation at 37°C. Tolerance against 6% acetic acid and 9% ethanol was observed. Osmotolerance study showed tolerance against 5% and 10% glucose giving 100% and 50% relative growth, respectively. Resistance against desiccation showed survival rate of 50% at 37°C after 5 h treatment and 10% after 20 h treatment. The best aeration rate in flasks for acetification was 70%. Polyphasic identification study based on biochemical, physiological and molecular characterization showed that the 5 isolates were all Acetobacter pasteurianus. Owing to their potentialities, these strains may be used as starters in vinegar production after conducting preservation studies.