The role of bacilli in cocoa fermentation is not well known. Their potential of production of pectinolytic enzymes during this process was evaluated. Bacillus growth was monitored and pectinolytic strains were screened for their use of pectin as sole carbon source. Effects of cocoa fermentation parameters susceptible to influence on enzyme production were analysed. Among 98 strains isolated, 90 were positive for pectin degradation and 80% of them presented detectable pectinolytic activities in submerged fermentation. Forty-eight strains produced polygalacturonase (PG), 47 yielded pectin lyase (PL) and 23 strains produced both enzymes. Bacilli growth was not significantly affected during fermentation. PL production was favoured by galactose, lactose, glucose as sugars, and arginine, glutamine, cysteine and ammonium sulphate as nitrogen compounds. Pectin at low concentration (0.05%) and iron stimulated PL production. It was strongly repressed by galacturonic acid (1%), and negatively affected by nitrogen starvation, zinc and temperatures above 45°C. PL yield was very weak below pH 4.0 and in anaerobic conditions. PG production was weakened by sucrose and cation depletion. It was increased slightly by cysteine, ammonium nitrate and nitrogen starvation and significantly above 40°C. PG synthesis was not affected by acidic pH (3.0-6.0) or oxygen availability. As fermentation products, lactate and acetate lowered the production of both enzymes while ethanol had no effect. The high proportion of pectinolytic producers among the strains studied and analysis of factors influencing pectinolytic enzymes production, suggest that Bacillus sp. is liable to produce at least one enzyme during cocoa fermentation.

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Microbial pectinolytic strains are targeted as potential starter to control cocoa fermentation. This study analyses the ability of yeasts pectinolytic strains to grow under stress conditions. After an initial growth, a decline trend was observed in yeast growth cycle during the cocoa fermentation. The 36 yeasts pectinolytic strains screened from 205 isolates showed tolerance to both alcoholic stress (10-12% alcohol) and thermic stress (up to 40°C) corresponding to surviving population round 75%. However, temperature-alcohol cross stress provokes full inhibition of strains that failed to grow at only 35°C under 8-10% alcohol. As acid stress, citric acid at 4% has the same effect as alcohol. In contrast, acetic acid and lactic acid respectively at 0.5% and 2% exerted individually, a higher pressure on yeast growth inhibiting up to 60% the fungal population. However, the viability of yeasts strains to a given concentration of lactic (1%) or acetic (0.25%) acid proved to be relatively stable with YS201 at increasing temperature up to 40°C. Cross stress involving temperature and alcohol or single acid stress may be the limiting factor for yeasts pectinolytic growth as starter in controlled cocoa fermentation.

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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.

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Pectinolytic enzymes play an important role in cocoa fermentation. In this study, we characterized three extracellular pectate lyases (Pels) produced by bacilli isolated from fermenting cocoa beans. These enzymes, named Pel-22, Pel-66, and Pel-90, were synthesized by Bacillus pumilus BS22, Bacillus subtilis BS66, and Bacillus fusiformis BS90, respectively. The three Pels were produced under their natural conditions and purified from the supernatants using a one-step chromatography method. The purified enzymes exhibited optimum activity at 60°C, and the half-time of thermoinactivation at this temperature was approximately 30 min. Pel-22 had a low specific activity compared with the other two enzymes. However, it displayed high affinity for the substrate, about 2.5-fold higher than those of Pel-66 and Pel-90. The optimum pHs were 7.5 for Pel-22 and 8.0 for Pel-66 and Pel-90. The three enzymes trans-eliminated polygalacturonate in a random manner to generate two long oligogalacturonides, as well as trimers and dimers. A synergistic effect was observed between Pel-22 and Pel-66 and between Pel-22 and Pel-90, but not between Pel-90 and Pel-66. The Pels were also strongly active on highly methylated pectins (up to 60% for Pel-66 and Pel-90 and up to 75% for Pel-22). Fe 2؉ was found to be a better cofactor than Ca 2؉ for Pel-22 activity, while Ca 2؉ was the best cofactor for Pel-66 and Pel-90. The amino acid sequences deduced from the cloned genes showed the characteristics of Pels belonging to Family 1. The pel-66 and pel-90 genes appear to be very similar, but they are different from the pel-22 gene. The characterized enzymes form two groups, Pel-66/Pel-90 and Pel-22; members of the different groups might cooperate to depolymerize pectin during the fermentation of cocoa beans.