جستجوی مقالات مرتبط با کلیدواژه "deep eutectic solvents" در نشریات گروه "زیست شناسی"

Due to the resistance of pathogenic bacteria and fungi to common drugs and the inclination towards natural food preservatives, researchers are exploring antimicrobial agents of plant with organic origin as alternative compounds. This study aims to investigate the antibacterial and antifungal properties of various extracts of Vitis vinifera L. cv. Ghizil Uzum grape skin and seeds extracted through different methods.

Grape seed and skin extracts were obtained using maceration, sonication, deep eutectic solvent (DES), and a combination of sonication-DES methods. The antibacterial and antifungal properties of the extracts were determined using the agar well diffusion method, as well as the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) (or minimum fungicidal concentration, MFC) against Staphylococcus aureus, Salmonella typhimurium, Escherichia coli and Listeria monocytogenes as well as on Aspergillus flavus, Fusarium solani, Cladosporium and Penicillium citrinum.

The results showed that the combined sonication-DES method had the lowest MIC (0.78 mg/ml) and MBC (1.56 mg/ml) for the skin and seed extracts, indicating the effectiveness of this method in extracting phenolic compounds compared to other conventional methods (p≤ 0.05). Additionally, L. monocytogenes and S. aureus exhibited the lowest MIC and MBC values among the tested bacteria , while Cladosporium showed the lowest MIC and MFC among the fungi. Furthermore, grape seed extract obtained through the sonication-DES method demonstrated higher capability in controlling and inhibiting the growth of pathogenic bacteria, fungi, and spoilage microorganisms compared to other extraction methods, making it a promising extraction method for herbal compounds.

Deep eutectic solvents (DES) are significantly important in enzymatic reactions. These solvents increase the efficient contact between substrate and enzyme and therefore, may increase enzyme stability and activity. Bioluminescence is the production and emission of light by a living organism. The principal chemical reaction in bioluminescence involves the light-emitting pigment luciferin and the enzyme luciferase. The enzyme catalyzes the oxidation of luciferin, which requires the energy-carrying molecule adenosine triphosphate (ATP). Because of its easily detectable product, luciferase has found a wide range of application in biotechnology and molecular biology. However, its low thermostability, low turnover number and high Km for ATP restrict further use of luciferase based systems in commercial application. Newly developed method which can be used to increase the stability of proteins and biocatalysts is to take advantage of Deep eutectic solvents (DESs). One group of Deep eutectic solvents are generally composed of organic salts with hydrogen bond donors, as a result of which hydrogen bonds are formed. In this study, we investigated the effects of these solvents on kinetic properties of wild type and E354R/Arg356 mutant Lampyris turkestanicus luciferases in the presence of choline chloride: glycerol with molar ratio of 2:1 as DES. For this, both wild type and mutant, expressed in Escherichia coli BL21, the protein of interest purified through affinity chromatography and used for kinetic studies. Based on the obtained results, DES has positive effect on the thermostability of wild type and mutant luciferases.

Firefly luciferase is a light generating enzyme, which is used in different fields of biotechnology and molecular biology. Luciferase has found widespread applications in many areas of genetic analysis such as detecting gene expression, reporter gene assay and proteomics studies such as protein-protein interactions. Despite many advantages, there are some limitations in luciferase-based systems, the most important of which is its low stability. One of the newly developed methods to solve this problem is to take advantage of Deep Eutectic Solvents (DES). One group of DESs is those that composed of organic salts with hydrogen donor, due to which, intermolecular hydrogen bonds cause lower melting point in comparison with each of the component. In this study, we investigated the effects of DES on kinetic properties of wild type and I232R - E354R/Arg356 mutant Lampyris turkestanicus luciferases. For this, both enzymes, wild type and mutant, expressed in BL21, the protein of interest purified through affinity chromatography and used for kinetic studies. Here, we used choline chloride: glycerol as DES. According to the results, the wild type luciferase is much more thermostable in DES than I232R - E354R/Arg356 mutant. Furthermore, the remaining activity of both wild type and mutant luciferases are greater in the presence of DES than those in the absence of DES.