Biodegradation of p-cresol by Pseudomonas spp.

International audiencePhenols are toxic to several biochemical reactions. However, biological transformation of phenols to nontoxic entities exists in specialized microbes, owing to enzymatic potential involving enzymes of aromatic catabolic pathways. In this study, a series of experiments were performed to examine the effects of the mineral medium composition and the pH on p-cresol removal. In this purpose, p-cresol biodegradation was carried out in a batch reactor containing mixed bacteria; the temperature (30°C), the stirring velocity (200 rpm), the KH2PO4 concentration (1.5 g/L), the K2HPO4 concentration (2 g/L), and p-cresol concentration (100 mg/L) were kept constants. The initial pH was varied in the range 5–9 and the mineral components were tested in the following concentration ranges: 0–2 g/L for Nitrogen sources (NH4Cl, KNO3, and NH4NO3), 0–0.5 g/L for NaCl, and 0–0.2 g/L for MgSO4. Their effects on p-cresol biodegradation and specific growth rate were examined. The shorter biodegradation time of p-cresol was 30.5 h for NH4Cl, NaCl, and MgSO4 concentrations of 1, 0.3, and 0.1 g/L, respectively. Maximum specific growth rate (0.34 h−1) and total p-cresol removal were recorded for an optimal pH value of 8

Mécanisme du transfert pervaporatif des mélanges aqueux d'acétate d'éthyle à travers des membranes en PDMS

L'étude porte sur le transfert du système “eau - acétate d'éthyle" à travers un matériau polymère, la polydiméthylsiloxane, réticulé à différents degrés. À partir des résultats expérimentaux, le transfert de matière a pu être exprimé pour les faibles teneurs en ester, en utilisant la loi de Fick dans laquelle le coefficient de diffusion est constant. L'absence de couplage des flux est démontrée par le fait que le coefficient de diffusion de l'eau dans le silicone rendant compte du transfert global en pervaporation est identique à sa valeur mesurée à l'état pur

Kinetic modelization of phenol biodegradation using Monod and Haldane models - effect of ammonium chlorid concentration

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First detection of vanA positive Enterococcus faecium clonal complex 17 in hospital wastewater in Algeria: an epidemiological report

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