Publications by authors named "Michalis Koutinas"

An environmental toxicological assessment of fourteen furanic compounds serving as valuable building blocks produced from biomass was performed. The molecules selected included well studied compounds serving as control examples to compare the toxicity exerted against a variety of highly novel furans which have been additionally targeted as potential or current alternatives to biofuels, building blocks and polymer monomers. The impact of the furan platform chemicals targeted on widely applied ecotoxicity model organisms was determined employing the marine bioluminescent bacterium and the freshwater green microalgae , while their ecotoxicity effects on plants were assessed using dicotyledonous plants and .

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Current knowledge on the capacity of plastics as vectors of microorganisms and their ability to transfer microorganisms between different habitats (i.e. air, soil and river) is limited.

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An orange peel waste biorefinery was developed employing a design of experiments approach to optimize the ultrasound-assisted dilute acid hydrolysis process applied for production of useful commodities. Central composite design-based response surface methodology was used to approximate the combined effects of process parameters in simultaneous production of essential oils, pectin and a sugar-rich hydrolyzate. Application of a desirability function determined the optimal conditions required for maximal production efficiency of essential oils, pectin and sugars as 5.

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Pseudomonas citronellolis SJTE-3 was isolated as a highly efficient microorganism for biodegradation and valorization of drilling fluids (DF) wastewater. The strain metabolised DF and oily mud exhibiting up to 93%, 86%, 85% and 88% of chemical oxygen demand (COD), n-dodecane, n-tetradecane and naphthalene removal efficiency respectively. Enhanced bioconversion was enabled through production of biosurfactants that reduced the surface tension of water by 53% and resulted in 43.

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Cytokine storm can result from cancer immunotherapy or certain infections, including COVID-19. Though short-term immune-related adverse events are routinely described, longer-term immune consequences and sequential immune monitoring are not as well defined. In 2006, six healthy volunteers received TGN1412, a CD28 superagonist antibody, in a first-in-man clinical trial and suffered from cytokine storm.

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A process for the valorization of citrus peel waste (CPW) has been developed aiming to produce succinic acid and a series of added-value products through the biorefinery platform. CPW was subject to physicochemical and biological treatment to isolate essential oils (0.43%) and pectin (30.

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Background: Lupanine is a plant toxin contained in the wastewater of lupine bean processing industries, which could be used for semi-synthesis of various novel high added-value compounds. This paper introduces an environmental friendly process for microbial production of enantiopure lupanine.

Results: Previously isolated P.

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This paper deals with the development of a citrus peel waste (CPW) biorefinery that employs low environmental impact technologies for production of ethanol and methane. Three major yeasts were compared for ethanol production in batch fermentations using CPW pretreated through acid hydrolysis and a combination of acid and enzyme hydrolysis. The most efficient conditions for production of CPW-based hydrolyzates included processing at 116 °C for 10 min.

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Article Synopsis
  • Ionic liquids (ILs) are persistent environmental contaminants with toxicity issues, but the microorganism Sphingomonas sp. MKIV can biodegrade some major types of ILs.
  • MKIV showed impressive bioremediation capabilities, achieving over 90% removal efficiency for specific ILs, although its metabolic activity was hindered by the presence of certain compounds.
  • A toxicological assessment revealed moderate to low toxicity of the ILs tested, and MKIV's ability to produce biopolymer from glucose suggests potential applications in bioremediation and industrial processes.
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Currently, design and optimisation of biotechnological bioprocesses is performed either through exhaustive experimentation and/or with the use of empirical, unstructured growth kinetics models. Whereas, elaborate systems biology approaches have been recently explored, mixed-substrate utilisation is predominantly ignored despite its significance in enhancing bioprocess performance. Herein, bioprocess optimisation for an industrially-relevant bioremediation process involving a mixture of highly toxic substrates, m-xylene and toluene, was achieved through application of a novel experimental-modelling gene regulatory network - growth kinetic (GRN-GK) hybrid framework.

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This work explores the potential for development of a lupanine valorization process evaluating different isolated microorganisms for their capacity to metabolize the alkaloid. Ecotoxicological assessment demonstrated that lupanine is toxic for Vibrio fischeri and Daphnia magna exhibiting EC values of 89 mg L and 47 mg L respectively, while acting both as growth inhibitor for a monocotyledonous and as promoter for a dicotyledonous plant. Among the eight aerobic and anaerobic strains isolated and identified Rhodococcus rhodochrous LPK211 achieved 81% removal for 1.

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Article Synopsis
  • The study investigates improving ethyl lactate (EL) production using enzymatic esterification, comparing various organic solvents for their effectiveness.
  • Chloroform and hexane were found to be the best solvents at low acid concentrations, yielding up to 88% and 75% EL, respectively, with higher LogP values correlating to better yields.
  • While commercial enzymes like Novozym 435 were the most efficient, non-commercial biocatalysts showed promise for hydrolysis, providing a cost-effective option despite lower overall esterification performance.
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Toluene is a pollutant catabolised through the interconnected pWW0 (TOL) and ortho-cleavage pathways of Pseudomonas putida mt-2, while upon succinate and toluene mixtures introduction in batch cultures grown on M9 medium, succinate was previously reported as non-repressing. The effect of a 40 times lower succinate concentration, as compared to literature values, was explored through systematic real-time qPCR monitoring of transcriptional kinetics of the key TOL Pu, Pm and ortho-cleavage PbenR, PbenA promoters in mixed-substrate experiments. Even succinate trace inhibited transcription leading to bi-modal promoters expression.

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The TOL plasmid promoters are activated by toluene leading to gene expression responsible for the degradation of the environmental signal. Benzoate is formed as an intermediate, activating the BenR protein of the chromosomal ortho-cleavage pathway that up-regulates the chromosomal PbenA promoter and the TOL Pm promoter resulting in cross-talk between the two networks. Herein, the transcriptional kinetics of the PbenR and PbenA promoters in conjunction with TOL promoters was monitored by real-time PCR during toluene biodegradation of different concentrations in batch cultures.

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Vanillin is a high value added product with many applications in the food, fragrance and pharmaceutical industries. A natural and low-cost method to produce vanillin is by microbial bioconversions through ferulic acid. Until now, limited microorganisms have been found capable of bioconverting ferulic acid to vanillin at high yield.

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This work explores the potential for the development of a hybrid fermentation-enzymatic process for the production of ethyl lactate from dairy waste. Cheese whey was used in Kluyveromyces marxianus and Lactobacillus bulgaricus batch cultures to produce ethanol and lactic acid respectively. Subsequently, the fermentation products were transferred into an organic phase through liquid-liquid extraction and ethyl lactate was formed in an esterification reaction catalyzed by lipases.

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The complexity of the regulatory network and the interactions that occur in the intracellular environment of microorganisms highlight the importance in developing tractable mechanistic models of cellular functions and systematic approaches for modelling biological systems. To this end, the existing process systems engineering approaches can serve as a vehicle for understanding, integrating and designing biological systems and processes. Here, we review the application of a holistic approach for the development of mathematical models of biological systems, from the initial conception of the model to its final application in model-based control and optimisation.

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The Notch1 signalling pathway has been shown to control neural stem cell fate through lateral inhibition of mash1, a key promoter of neuronal differentiation. Interaction between the Delta1 ligand of a differentiating cell and the Notch1 protein of a neighbouring cell results in cleavage of the trans-membrane protein, releasing the intracellular domain (NICD) leading to the up regulation of hes1. Hes1 homodimerisation leads to down regulation of mash1.

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The majority of models describing the kinetic properties of a microorganism for a given substrate are unstructured and empirical. They are formulated in this manner so that the complex mechanism of cell growth is simplified. Herein, a novel approach for modelling microbial growth kinetics is proposed, linking biomass growth and substrate consumption rates to the gene regulatory programmes that control these processes.

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The structure of the extant transcriptional control network of the TOL plasmid pWW0 born by Pseudomonas putida mt-2 for biodegradation of m-xylene is far more complex than one would consider necessary from a mere engineering point of view. In order to penetrate the underlying logic of such a network, which controls a major environmental cleanup bioprocess, we have developed a dynamic model of the key regulatory node formed by the Ps/Pr promoters of pWW0, where the clustering of control elements is maximal. The model layout was validated with batch cultures estimating parameter values and its predictive capability was confirmed with independent sets of experimental data.

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This work investigates the use of an oil absorber as an operational strategy in vapor phase bioreactors exposed to starvation periods, during the treatment of inhibitory pollutants. After being exposed to 1,2-dichloroethane (DCE) starvation periods, the response and stability of a combined oil-absorber-bioscrubber (OAB) system was compared to that of a bioscrubber only (BO) system. In the BO system, after a 5.

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Biotreatment technologies offer a cost-effective and efficient method for dealing with point-source releases of solvents. However, a major problem hampering these technologies is the fluctuating pollutant loads, which is especially critical for inhibitory pollutants. Provision of biotreatment systems able to cope with this problem is a significant technological and environmental challenge.

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