Testing of the new streptomyces strains for production of phenoloxidases

International audienc

Optimization of Different Key Culture Conditions for Enhanced Biodegradation of a Refractory Emerging Pollutant by a Bacterial Isolate Through a Statistical Approach

International audienc

Increase of the Trametes Versicolor Efficiency in the Bioremediation Process for Diclofenac Biodegradation in Aquatic Environments

International audienceDiclofenac (DCF) is a non-steroidal anti-inflammatory drug and, as pollutant, it represents a persistent residue hazard to health and to the environment. Trametes versicolor was previously selected for its ability in diclofenac biodegradation (up to 20%) during cultivation in submerged system under aerobic conditions at an initial DCF concentration of 10 mg L-1. The influence of some factors such as nitrogen sources glucose, MnSO4 center dot H2O, CuSO4 center dot 5H(2)O, inoculum level, initial DCF concentration and incubation time, upon the biodegradation potential was examined by Plackett-Burman analysis. The parameters significantly influencing the DCF biotransformation were found to be yeast extract, glucose, CuSO4 center dot 5H(2)O and inoculum level. In these optimum conditions, the DCF biotransformation yield was 80%. This result was 60% superior in comparison with the medium without optimization. Analysis of variance exhibited a high coefficient of determination (R-2) value of 0.9987 and ensured that the polynomial model with the experimental data was a satisfactory one. Optimal conditions obtained in this work led to a solid foundation for further use of Trametes versicolor in biotreatment of high strength DCF pollutant effluents in water waste

Screening of soil bacteria as potential agents for drugs biodegradation: a case study with clofibric acid

International audienceBACKGROUND Clofibric acid (CLF), the main pharmacologically active metabolite of blood lipid regulating pharmaceutical clofibrat, etofibrat, etofyllinclofibrat is one of the most widely reported drugs found in water. It is hardly or not degraded by the conventional technology used in wastewater treatment plants. RESULTS Sixteen new filamentous bacteria belonging to genus Streptomyces spp. isolated from different Romanian soil samples and three strains from a collection of microorganisms (MIUG) were morphologically characterized, tested based on their resistance against clofibric acid toxicity and then investigated as bioremediation agents. Only five Streptomyces spp. isolates coded MIUG 4.88, MIUG 4.89, LP1, LP2, SNA, showed high CLF tolerance at most of the concentrations tested (0.2, 0.5, 1, 5, 8 mg L−1). CONCLUSION The data obtained showed that only the strain Streptomyces MIUG 4.89 presents promising potential for clofibric acid biodegradation, with an elimination yield of 35%, which was not reported for this class of bacteria to date. However, further research is needed for optimization of the CLF biodegradation conditions to enhance its bioremediation yield especially in polluted aquatic systems. © 2016 Society of Chemical Industr

Improving Biodegradation of Clofibric Acid by Trametes pubescens through the Design of Experimental Tools

International audienceClofibric acid (CLF) is the main pharmacologically active metabolite in composition of the pharmaceutical products used for controlling blood lipid content. This xenobiotic compound is highly persistent in the aquatic environment and passes unchanged or poorly transformed in wastewater treatment plants. A white-rot fungal strain of Trametes pubescens was previously selected, for its ability for clofibric acid biodegradation (up to 30%) during cultivation in submerged system under aerobic conditions at an initial CLF concentration of 15 mg L−1. Plackett-Burman design (PBD) and response surface methodology (RSM) were used for experimental planning, mathematical modelling and statistical analysis of data of the biotechnological process of CLF biotransformation by Trametes pubescens fungal strain. After optimization, the capacity of the selected Trametes pubescens strain to degrade CLF was increased by cultivation in a liquid medium containing 3 g·L−1 yeast extract, 15 g·L−1 peptone, 5 g·L−1 glucose and mineral salts, inoculated at 2% (v/v) vegetative inoculum and cultivated at pH 5.5, during 14 days at 25 °C and 135 rpm. In these optimized biotechnological conditions, the CLF biotransformation yield was 60%

Response surface optimization of experimental conditions for carbamazepine biodegradation by Streptomyces MIUG 4.89.

International audienc

Potential of newly isolated wild Streptomyces strains as agents for the biodegradation of a recalcitrant pharmaceutical, carbamazepine

International audienceCarbamazepine (CBZ) is a recalcitrant xenobiotic pharmaceutical pollutant highly stable in soil and wastewater during treatment. The biodegradation of CBZ using streptomycetes has been few studied up to now. Sixteen newly filamentous bacteria belong to genus Streptomyces spp. isolated from different Romanian soil samples and three strains from a collection of microorganisms (MIUG) were morphologically characterized, tested based on their resistance against CBZ toxicity and then selected as agents for bioremediation. Five Streptomyces spp. strains coded MIUG 4.88, MIUG 4.89, SNA, LP1 and LP2 showed CBZ tolerance at all of the tested concentrations, i.e. 0.05, 0.2, 1, 5 and 8 mg L−1. Two of these (MIUG 4.89 and SNA strains) were selected based on their resistance to target compound and were then assessed for CBZ biodegradation. The strain Streptomyces MIUG 4.89 showed an interesting efficiency for CBZ removal, with a yield of 35% when it was cultivated in submerged conditions on a minimal medium supplemented with 5 g L−1 glucose. This ability was linked to extracellular laccase production. These results are promising for the use of these filamentous bacteria as bioremediation agents

Green “one-pot” fluorescent bis-indolizine synthesis with whole-cell plant biocatalysis

An efficient one-pot route leading to bis-indolizine symmetric compounds has been developed via a new approach from the dipyridinium heterocyclic compound, reactive halogenated derivative, and activated alkyne through biocatalysis. A set of local plants was evaluated for its catalytic potential in “one-pot” biocatalysis of these valuable fluorescent compound synthesis reactions. Most of these biocatalysts containing enzymes from the oxidoreductase class (peroxidase: 0.56–1.08 mmol purpurogallin‧g−1 fresh weight‧min−1, polyphenol oxidase (PPO) : 27.19–48.95 PPO units‧mg tissue−1, CAT: 3.27–21.71 µmol O2‧g−1 fresh weight‧min−1), were used as green catalysts in the multi-component cycloaddition reaction, in an aqueous buffer solution, for the production of bis-indolizine compounds in moderate to excellent yields (45–85%). The horseradish root (Armoracia rusticana) has been selected as the most promising biocatalyst source among the evaluated plants, and the obtained yields were greater than in the conventional synthesis method. The structures of indolizine derivatives were confirmed by nuclear magnetic resonance spectra, elemental analyses, as well as Fourier transform-infrared spectra. The cytotoxicity of the latter obtained indolizine compounds on the growth of the model microorganism, Saccharomyces cerevisiae MIUG 3.6 yeast strain, was also evaluated. Various parameters (number of generations, growth rate, generation time, dry matter yield, the degree of the budding yeast cells, and the degree of yeast autolysis, fermentation intensity), which describe the yeast growth, suggest that the nutrient broth supplemented with different concentrations of bis-indolizine compounds (10 and 1 µM) had no toxic effect on the yeast strain growth, under submerged cultivation conditions