PubMed İndeksli Yayınlar Koleksiyonu / PubMed Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7645
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Article Enhanced Catalytic Performance of Rhizomucor Miehei Lipase on Di-N and Diethylhexyl Phthalates: Insights Into Substrate Specificity and Immobilization Strategy(Taylor & Francis Ltd, 2025) Balci, Esin; Rosales, Emilio; Curras, Marta Pazos; Sofuoglu, Aysun; Sanroman, M. A.Di-n-butyl (DnBP) and Diethylhexyl Phthalates (DEHP), known as potential endocrine disruptors, are priority pollutants categorized by many regulatory agencies. Enzymatic degradation is a green and efficient approach to remove PEs in the environment. In this study, the DnBP and DEHP degradation performance of Rhizomucor miehei lipase (palatase) in free and immobilized forms on Halloysite nanoclays (HNCs) in an aqueous system was investigated. Upon enzyme immobilization, the alterations in the palatase's secondary structure were examined using the circular dichroism (CD) analysis. The binding affinity of DnBP and DEHP to palatase was evaluated with molecular docking approaches. The enzyme's immobilization efficiency and relative activity were found to be 80.3% and 87.8%, respectively. CD results revealed that palatase retained its secondary structure to a significant extent. HNCs-palatase (HNCs-P) exhibited a high stability, as the structural integrity of palatase was mostly preserved. Both free palatase (FP) and HNCs-P fully degraded DnBP and DEHP (100 mg/L) to phthalic acid and a degradation pathway of DnBP and DEHP was suggested. Immobilization prevented the enzyme inhibition caused by the accumulation of metabolites. After seven consecutive uses, HNCs-P was still able to degrade DnBP (63.3%) and DEHP (72.8%). Molecular docking results showed that DEHP had a higher affinity for palatase than DnBP. This study suggests that enzyme immobilization onto HNCs can increase their stability and catalytic performance. FP and HNCs-P effectively hydrolyse ester bonds responsible for phthalate toxicity. Considering their high efficiency, FP and HNCs-P can be used as potential phthalate degraders in various environmental remediation processes.Article Citation - WoS: 9Citation - Scopus: 13An Exposure–risk Assessment for Potentially Toxic Elements in Rice and Bulgur(Springer Verlag, 2017) Sofuoğlu, Sait Cemil; Sofuoğlu, AysunRice and wheat are rich sources of essential elements. However, they may also accumulate potentially toxic elements (PTE). Bulgur, the popular alternative to rice in the eastern Mediterranean, is produced by processing wheat, during which PTE content may change. This study determined PTE concentrations in rice and bulgur collected from 50 participant households in the City of Izmir, Turkey, estimated ingestion exposure, and associated chronic-toxic and carcinogenic human health risks. Comparison of the determined concentrations to the available standard levels and the levels reported in the literature revealed that Cd, Co, and Pb in rice might be of concern. The estimated health risks of individual participants supported this result with exceedance of respective threshold or acceptable risk levels at the 95th percentile. Population risk estimates indicated that the proportion with higher than the threshold or acceptable risk is about 10%, 24%, and 12% for Cd, Co, and Pb in rice, respectively. Results of this study showed that health risks associated with PTE exposure through bulgur consumption are lower than those of rice, and below the threshold or acceptable risk levels.