Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Article Citation - Scopus: 1Esterase-Mediated Degradation of Dibutyl and Diethylhexyl Phthalates in Aqueous and Soil Systems(Elsevier Ltd, 2025) Balci, E.; Sanli-Mohamed, G.; Sofuoglu, A.Phthalate esters (PAEs), widely used as plasticizers, pose severe environmental and health risks. This study investigated the enzymatic hydrolysis of PAE congeners (dibutyl phthalate (DBP) and diethylhexyl phthalate (DEHP)) in aqueous and soil systems using Bacillus subtilis esterase and a new thermoalkaliphilic Geobacillus sp. esterase. A novel esterase secreted from Geobacillus sp. which was isolated from a geothermal region (Türkiye) was expressed in E.coli and purified. Geobacillus sp. esterase was able to degrade almost 30% of DBP and 40% of DEHP (100 mg/L) in the aqueous system within 336 h, while it degraded virtually 59% and 98% of DBP in agricultural area soil (soil-1) and forest area soil (soil-2), respectively, at the same time. To compare with Geobacillus sp. esterase, Bacillus subtilis esterase was used, which fully degraded DBP with 100 mg/L in the soil-1 and soil-2 for 72 h and 2 h, respectively. The performances of both esterases to degrade DEHP (100 mg/L) were similar in soil-1 (∼35%) and soil-2 (∼50%) for 336 h. Soil characteristics significantly influenced PAE degradation. Compared to that in the aqueous system, Geobacillus sp. esterase in soil systems had a higher degradation efficiency. This was likely due to its origin from a soil microorganism. Variations in the degradation ability of two enzymes most probably arose from substrate specificities and enzyme dynamics. Molecular docking results showed that DBP had a higher affinity to both enzymes than DEHP. Overall, this study offers important evidence that Bacillus subtilis esterase and Geobacillus sp. esterase are effective biocatalysts for removing the pollutants with ester bonds in the environment. © 2025 Elsevier LtdArticle Citation - WoS: 29Citation - Scopus: 35Sustainable Bio-Nano Composite Coatings for the Protection of Marble Surfaces(Elsevier Masson SAS, 2015) Ocak, Y.; Sofuoglu, A.; Tihminlioglu, F.; Böke, H.Water repellency on natural stone surfaces is the most important issue in the protection of stone monuments from effects of atmospheric pollutants. In this study, effectiveness of a bio-nano composite coating, composed of a biodegradable polymer (poly-L-lactide [PLA]) and montmorillonite clay (MMT) was investigated for the protection of marble surfaces from pollution. The clay dispersion in polymer matrices was analyzed by using Scanning Tunnel Electron Microscopy (STEM) and X-Ray Diffraction (XRD), while protection performance was investigated by the measurement of surface roughness, wettability, water vapor permeability, capillary water absorption, and color changes on the marble surfaces. As a result, no alteration on the color of coated marbles was observed, significant improvement was obtained for hydrophobicity of the surface and inhibition of sulfation reaction on the exposed marble surfaces under acidic atmosphere. It could be said that PLA based nanocomposites seem to be promising materials as protective coating agents in reducing the effects of water and atmospheric pollutants on marble surfaces. © 2014 Elsevier Masson SAS.