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Ferradji F.Z.,Blida University | Mnif S.,University of Sfax | Badis A.,Blida University | Rebbani S.,National Center for Research and Development of Fisheries and Aquaculture | And 3 more authors.
International Biodeterioration and Biodegradation | Year: 2014

Petroleum and naphthalene (example of PAHs) degrading Streptomyces spp. isolates AB1, AH4, and AM2 were recovered from surface soils at Mitidja plain (North of Algeria). The degradation efficiencies were examined by HPLC and GC-MS analysis and the results showed that the biosurfactant producing isolates AB1, AH4 and AM2 could remove 82.36%, 85.23% and 81.03% of naphthalene after 12 days of incubation, respectively. During naphthalene degradation, a slight decrease in pH values was recorded for the three studied strains. Degradation metabolites were identified using GC-MS analysis of ethyl acetate extracts of the cell free-culture. The metabolism of degradation proceeds via the phthalic acid pathway for the three strains. Moreover, the selected strains showed an important degradation of the aliphatic fraction present in crude oil after 30 days of incubation. The finding suggests that the selected strains are suitable candidates for practical field application for effective in situ bioremediation of hydrocarbon-contaminated sites. © 2013 Elsevier Ltd.

Boulkour Touioui S.,Laboratory of Microbial Systems Biology LMSB | Boulkour Touioui S.,Blida University | Zarai Jaouadi N.,University of Sfax | Boudjella H.,Laboratory of Microbial Systems Biology LMSB | And 7 more authors.
World Journal of Microbiology and Biotechnology | Year: 2015

Streptomyces sp. strain AH4 exhibited a high ability to produce two extracellular proteases when cultured on a yeast malt-extract (ISP2)-casein-based medium. Pure proteins were obtained after heat treatment (30 min at 70 °C) and ammonium sulphate fractionation (30–60 %), followed by size exclusion HPLC column. Matrix assisted laser desorption ionization-time of flight mass spectrometry analysis revealed that the purified enzymes (named SAPS-P1 and SAPS-P2) were monomers with molecular masses of 36,417.13 and 21,099.10 Da, respectively. Their identified N-terminal amino acid displayed high homologies with those of Streptomyces proteases. While SAPS-P1 was optimally active at pH 12.0 and 70 °C, SAPS-P2 showed optimum activity at pH 10.0 and 60 °C. Both enzymes were completely stable within a wide range of temperature (45–75 °C) and pH (8.0–11.5). They were noted to be completely inhibited by phenylmethanesulfonyl fluoride and diisopropyl fluorophosphates, which confirmed their belonging to the serine proteases family. Compared to SAPS-P2, SAPS-P1 showed high thermostability and excellent stability towards bleaching, denaturing, and oxidizing agents. Both enzymes displayed marked stability and compatibility with a wide range of commercial laundry detergents and significant catalytic efficiencies compared to Subtilisin Carlsberg and Protease SG-XIV. Overall, the results indicated that SAPS-P1 and SAPS-P2 can be considered as potential promising candidates for future application as bioadditives in detergent formulations. © 2015, Springer Science+Business Media Dordrecht.

Jaouadi N.Z.,University of Sfax | Rekik H.,University of Sfax | Badis A.,Blida University | Trabelsi S.,University of Sfax | And 6 more authors.
PLoS ONE | Year: 2013

Dehairing is one of the highly polluting operations in the leather industry. The conventional lime-sulfide process used for dehairing produces large amounts of sulfide, which poses serious toxicity and disposal problems. This operation also involves hair destruction, a process that leads to increased chemical oxygen demand (COD), biological oxygen demand (BOD), and total suspended solid (TSS) loads in the effluent. With these concerns in mind, enzyme-assisted dehairing has often been proposed as an alternative method. The main enzyme preparations so far used involved keratinases. The present paper reports on the purification of an extracellular keratinase (KERUS) newly isolated from Brevibacillus brevis strain US575. Matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF/MS) analysis revealed that the purified enzyme was a monomer with a molecular mass of 29121.11 Da. The sequence of the 27 N-terminal residues of KERUS showed high homology with those of Bacillus keratinases. Optimal activity was achieved at pH 8 and 40°C. Its thermoactivity and thermostability were upgraded in the presence of 5 mM Ca2+. The enzyme was completely inhibited by phenylmethanesulfonyl fluoride (PMSF) and diiodopropyl fluorophosphates (DFP), which suggests that it belongs to the serine protease family. KERUS displayed higher levels of hydrolysis, substrate specificity, and catalytic efficiency than NUE 12 MG and KOROPON® MK EG keratinases. The enzyme also exhibited powerful keratinolytic activity that made it able to accomplish the entire feather-biodegradation process on its own. The kerUS gene encoding KERUS was cloned, sequenced, and expressed in Escherichia coli. The biochemical properties of the extracellular purified recombinant enzyme (rKERUS) were similar to those of native KERUS. Overall, the findings provide strong support for the potential candidacy of this enzyme as an effective and eco-friendly alternative to the conventional chemicals used for the dehairing of rabbit, goat, sheep and bovine hides in the leather processing industry. © 2013 Jaouadi et al.

Rekik H.,University of Sfax | Nadia Z.J.,University of Sfax | Bejar W.,University of Sfax | Kourdali S.,National Center for Research and Development of Fisheries and Aquaculture | And 9 more authors.
International Journal of Biological Macromolecules | Year: 2015

A novel extracellular lignin peroxidase (called LiP-SN) was produced and purified from a newly isolated Streptomyces griseosporeus strain SN9. The findings revealed that the pure enzyme was a monomeric protein with an estimated molecular mass of 43. kDa and a Reinheitzahl value of 1.63. The 19 N-terminal residue sequence of LiP-SN showed high homology with those of Streptomyces peroxidases. Its optimum pH and temperature were pH 8.5 and 65. °C, respectively. The enzyme was inhibited by sodium azide and potassium cyanide, suggesting the presence of heme components in its tertiary structure. Its catalytic efficiency was higher than that of the peroxidase from Streptomyces albidoflavus strain TN644. Interestingly, LiP-SN showed marked dye-decolorization efficiency and stability toward denaturing, oxidizing, and bleaching agents, and compatibility with EcoVax and Dipex as laundry detergents for 48. h at 40. °C. These properties make LiP-SN a potential candidate for future applications in distaining synthetic dyes and detergent formulations. © 2014 Elsevier B.V.

Boudjema K.,Blida University | Kourdali S.,National Center for Research and Development of Fisheries and Aquaculture | Bounakous N.,National Center for Research and Development of Fisheries and Aquaculture | Meknachi A.,National Center for Research and Development of Fisheries and Aquaculture | Badis A.,Blida University
Journal of Marine Biology | Year: 2014

Brown mussels (Perna perna) were exposed to cadmium (Cd), lead (Pb), and copper (Cu) concentrations under acute exposure and exposure-depuration tests for the estimation of biochemical biomarker catalase (CAT). The acute tests showed accumulated Cd, Pb, and Cu in Perna perna correlated linearly with the exposure concentrations (R 2 = 0.794, R 2 = 0.891, and R 2 = 0.985 for Cd, Pb, and Cu, resp.). The results of CAT increased significantly in tissues of treatment mussels after 72 h exposure when compared to control. The values of total protein were disturbed in exposed groups when compared with control. These results suggest that metabolites and catalase activity were affected by heavy metal exposures. Analysis using the Spearman rank correlation coefficient showed that the CAT activity appeared to have a significant positive correlativity (R s = 0.921, R s = 0.949, and R s = 0.949 for Cd, Pb, and Cu, resp.) with the accumulated Cd, Pb, and Cu concentrations, respectively. The result of exposure-depuration tests showed that there is a general tendency for CAT to decrease in depuration phase, suggesting that the induction of catalase is metal and/or mixture of metals dependent. © 2014 Kamel Boudjema et al.

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