Corvini, Philippe
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Biodegradation of sulfamethoxazole by a bacterial consortium of Achromobacter denitrificans PR1 and Leucobacter sp. GP
2018-12, Reis, Ana C., Cvancarova Småstuen, M., Liu, Ying, Lenz, Markus, Hettich, Timm, Kolvenbach, Boris, Corvini, Philippe, Nunes, Olga C.
In the last decade, biological degradation and mineralization of antibiotics have been increasingly reported feats of environmental bacteria. The most extensively described example is that of sulfonamides that can be degraded by several members of Actinobacteria and Proteobacteria. Previously, we reported sulfamethoxazole (SMX) degradation and partial mineralization by Achromobacter denitrificans strain PR1, isolated from activated sludge. However, further studies revealed an apparent instability of this metabolic trait in this strain. Here, we investigated this instability and describe the finding of a low-abundance and slow-growing actinobacterium, thriving only in co-culture with strain PR1. This organism, named GP, shared highest 16S rRNA gene sequence similarity (94.6–96.9%) with the type strains of validly described species of the genus Leucobacter. This microbial consortium was found to harbor a homolog to the sulfonamide monooxygenase gene (sadA) also found in other sulfonamide-degrading bacteria. This gene is overexpressed in the presence of the antibiotic, and evidence suggests that it codes for a group D flavin monooxygenase responsible for the ipso-hydroxylation of SMX. Additional side reactions were also detected comprising an NIH shift and a Baeyer–Villiger rearrangement, which indicate an inefficient biological transformation of these antibiotics in the environment. This work contributes to further our knowledge in the degradation of this ubiquitous micropollutant by environmental bacteria.
Isolation of two Ochrobactrum sp. strains capable of degrading the nootropic drug—Piracetam
2018-07, Woźniak-Karczewska, Marta, Cvancarová, Monika, Chrzanowski, Łukasz, Corvini, Philippe, Cichocka, Danuta
Piracetam (2-oxo-1-pyrrolidine acetamide) is a popular cognitive enhancer, which has recently been detected in waste and drinking water. Nootropic drugs are designed to affect human metabolism and act on the nervous system, but their environmental effects have yet to be the subject of detailed studies. In this report, we present the efficient biodegradation of the cognitive enhancer, piracetam. Two bacterial strains capable of using this compound as the sole carbon source were isolated and later identified as Ochrobactrum anthropi strain MW6 and Ochrobactrum intermedium strain MW7. The compound's mineralization and the cleavage of the heterocyclic ring were shown in the experiments with 14C-labeled piracetam. This is also the first report of a pharmaceutical's degradation by the Ochrobactrum genus. This study presents model microorganisms that can be used in further investigation of piracetam's degradation pathways as well as enzymes and genes involved in the process.
Production of superparamagnetic nanobiocatalysts for green chemistry applications
2016-04-23, Gasser, Christoph, Ammann, Erik, Schäffer, Andreas, Shahgaldian, Patrick, Corvini, Philippe
Immobilization of enzymes on solid supports is a convenient method for increasing enzymatic stability and enabling enzyme reuse. In the present work, a sorption-assisted surface conjugation method was developed and optimized to immobilize enzymes on the surface of superparamagnetic nanoparticles. An oxidative enzyme, i.e., laccase from Trametes versicolor was used as model enzyme. The immobilization method consists of the production of superparamagnetic nanoparticles by co-precipitation of FeCl2 and FeCl3. Subsequently, the particle surface is modified with an organosilane containing an amino group. Next, the enzymes are adsorbed on the particle surface before a cross-linking agent, i.e., glutaraldehyde is added which links the amino groups on the particle surface with the amino groups of the enzymes and leads to internal cross-linking of the enzymes as well. The method was optimized using response surface methodology regarding optimal enzyme and glutaraldehyde amounts, pH, and reaction times. Results allowed formulation of biocatalysts having high specific enzymatic activity and improved stability. The biocatalysts showed considerably higher stability compared with the dissolved enzymes over a pH range from 3 to 9 and in the presence of several chemical denaturants. To demonstrate the reusability of the immobilized enzymes, they were applied as catalysts for the production of a phenoxazinone dye. Virtually, 100 % of the precursor was transformed to the dye in each of the ten conducted reaction cycles while on average 84.5 % of the enzymatic activity present at the beginning of a reaction cycle was retained after each cycle highlighting the considerable potential of superparamagnetic biocatalysts for application in industrial processes.
Biomineralisierung von Selen: Von Abwasserbehandlung zu Ressourcen-Wiedergewinnung
2015, Lenz, Markus, Kolvenbach, Boris, Corvini, Philippe
Bio- and photodegradation of fungicides in agro-industrial wastewater
2018-11, Cvancarova Småstuen, Milada, Svojitka, Jan, Corvini, Philippe
Biotransformation of ritalinic acid by laccase in the presence of mediator TEMPO
2018-07, Kobakhidze, Aza, Elisashvili, Vladimir, Corvini, Philippe, Cvancarova Småstuen, M.
Methylphenidate is widely used as a medication for the treatment of attention deficit hyperactivity disorder (ADHD) in children. Less than 1% of methylphenidate is excreted unchanged in urine, while 80% of an oral dose is excreted as ritalinic acid (which is reportedly poorly degradable). This study aims to investigate the biotransformation of ritalinic acid by free and immobilized enzymes. The influence of various laccase mediators on biotransformation efficiency has been tested. Formation of the main transformation products has been monitored and their potential structures suggested. The effective transformation of ritalinic acid was observed only in the presence of 2,2,6,6-tetramethylpiperidine 1-oxyl mediator (TEMPO). The most effective enzyme was the laccase of T. versicolor 159. The main transformation product was an N-methyl derivative of ritalinic acid. Ritalinic acid was also reduced to aldehyde and alcohol, and a broad spectrum of intermediate complexes with oxoammonium ion of TEMPO were detected. This is the first time the biotransformation of ritalinic acid has been investigated in detail.
Environmental aspects of printable and organic electronics (POE)
2016-04, Hengevoss, Dirk, Zimmermann, Yannick, Brun, Nadja, Hugi, Christoph, Corvini, Philippe, Lenz, Markus, Fent, Karl, Nisato, Giovanni, Lupo, Donald, Ganz, Simone
Bacterial isolates degrading ritalinic acid—human metabolite of neuro enhancer methylphenidate
2018-07, Woźniak-Karczewska, Marta, Cvancarová, Monika, Chrzanowski, Łukasz, Corvini, Philippe, Cichocka, Danuta
The consumption of nootropic drugs has increased tremendously in the last decade, though the studies on their environmental fate are still scarce. Nootropics are bioactive compounds designed to alter human's physiology therefore the adverse effects towards wildlife can be expected. In order to understand their environmental impact, the knowledge on their transformation pathways is necessary. Methylphenidate belongs to the most prescribed neuro-enhancers and is among the most favored smart drugs used in non-medical situations. It is metabolized in human liver and excreted as ritalinic acid. Here, we showed for the first time that ritalinic acid can be biodegraded and used as a sole carbon and nitrogen source by various microbial strains originating from different environmental samples. Five axenic strains were isolated and identified as: Arthrobacter sp. strain MW1, MW2 and MW3, Phycicoccus sp. strain MW4 and Nocardioides sp. strain MW5. Our research provides the first insight into the metabolism of ritalinic acid and suggests that it may differ depending on the strain and growth conditions, especially on availability of nitrogen. The isolates obtained in this study can serve as model organisms in further studies on the catabolism of ritalinic acid and methylphenidate but potentially also other compounds with similar structures. Our findings have important implication for the sewage epidemiology. We demonstrated that ritalinic acid is subject to quick and efficient biodegradation thus its use as a stable biomarker should be reconsidered.
Rhizobacteria and Plant Symbiosis in Heavy Metal Uptake and Its Implications for Soil Bioremediation
2017, Sobariu, Dana Luminita, Fertu, Daniela Ionela, Diaconu, Mariana, Pavel, Lucian Vasile, Hlihor, Raluca-Maria, Dragoi, Elena Niculina, Curteanu, Silvia, Lenz, Markus, Corvini, Philippe, Gavrilescu, Maria
Certain species of plants can benefit from synergistic effects with plant growth-promoting rhizobacteria (PGPR) that improve plant growth and metal accumulation, mitigating toxic effects on plants and increasing their tolerance to heavy metals. The application of PGPR as biofertilizers and atmospheric nitrogen fixators contributes considerably to the intensification of the phytoremediation process. In this paper, we have built a system consisting of rhizospheric Azotobacter microbial populations and Lepidium sativum plants, growing in solutions containing heavy metals in various concentrations. We examined the ability of the organisms to grow in symbiosis so as to stimulate the plant growth and enhance its tolerance to Cr(VI) and Cd(II), to ultimately provide a reliable phytoremediation system. The study was developed at the laboratory level and, at this stage, does not assess the inherent interactions under real conditions occurring in contaminated fields with autochthonous microflora and under different pedoclimatic conditions and environmental stresses. Azotobacter sp. bacteria could indeed stimulate the average germination efficiency of Lepidium sativum by almost 7%, average root length by 22%, average stem length by 34% and dry biomass by 53%. The growth of L. sativum has been affected to a greater extent in Cd(II) solutions due its higher toxicity compared to that of Cr(VI). The reduced tolerance index (TI, %) indicated that plant growth in symbiosis with PGPR was however affected by heavy metal toxicity, while the tolerance of the plant to heavy metals was enhanced in the bacteria-plant system. A methodology based on artificial neural networks (ANNs) and differential evolution (DE), specifically a neuro-evolutionary approach, was applied to model germination rates, dry biomass and root/stem length and proving the robustness of the experimental data. The errors associated with all four variables are small and the correlation coefficients higher than 0.98, which indicate that the selected models can efficiently predict the experimental data.
Immobilization of an artificial imine reductase within silica nanoparticles improves its performance
2016, Hestericová, Martina, Correro, Maria Rita, Lenz, Markus, Corvini, Philippe, Shahgaldian, Patrick, Ward, Thomas R.
Silica nanoparticles equipped with an artificial imine reductase (biotinylated iridium complex conjugated with streptavidin) display marked redn. activity toward cyclic imines and NAD. The method, based on immobilization and protection of streptavidin on silica nanoparticles, shields the biotinylated metal cofactor against deactivation yielding >46,000 turnovers in pure samples and 4000 turnovers in crude cellular exts.