{"title":"Immobilization of Xylanase into Zeolitic Imidazolate Framework-67 (ZIF-67) and Manganese-Doped ZIF-67 (Mn/ZIF-67): A Comparison Study","authors":"Büşra Bakar, Gamze Dik, Ahmet Ulu, Burhan Ateş","doi":"10.1007/s11244-023-01898-1","DOIUrl":null,"url":null,"abstract":"<p>It has been discovered that metal–organic frameworks (MOFs) have desirable qualities for the immobilization of enzymes, including a high surface area, significant interior pore volumes, and easily changeable pore size. Herein, the xylanase (Xyl) enzyme was immobilized for the first time to two different carrier supports, zeolitic imidazolate framework-67 (ZIF-67) and manganese-doped ZIF-67 (Mn/ZIF-67) by in situ method. The physicochemical characterizations of MOFs with and without Xyl were performed by FT-IR, XRD, SEM, and EDAX techniques. Xyl@ZIF-67 and Xyl@Mn/ZIF-67 were evaluated in terms of optimum temperature, optimum pH, kinetic parameters, thermal stability, reusability as well as juice clarification and compared with free Xyl. Optimum temperature values were 50 °C for Xyl@ZIF-67 and 70 °C for free Xyl and Xyl@Mn/ZIF-67. Optimum pH values for free Xyl, Xyl@ZIF-67, and Xyl@Mn/ZIF-67 were recorded as 6.0, 8.0, and 7.0, respectively. K<sub>m</sub> values for free Xyl, Xyl@ZIF-67, and Xyl@Mn/ZIF-67 were calculated as 3.139, 5.430, and 0.799 mg/mL, respectively, while V<sub>max</sub> values were calculated as 0.167, 0.226, and 0.062 µmol/min/mL, respectively. The results revealed that in comparison to the free Xyl, Xyl@ZIF-67, and Xyl@Mn/ZIF-67 exhibited more thermal resistance. After incubation at 70 °C for 120 min, the free Xyl remained at 28.7% of the activity, while the Xyl@ZIF-67 and Xyl@Mn/ZIF-67 remained at 85.7% and 40.0%, respectively. Moreover, after eight cycles, the Xyl@ZIF-67 and Xyl@Mn/ZIF-67 retained more than 70% of their initial activity. Further, the transmittance of apple juice was increased from 65.61 to 94.73% and from 77.80 to 84.13%, respectively, when Xyl@ZIF-67 and Xyl@Mn/ZIF-67 were used as biocatalysts. Overall, these findings indicated that the suggested Xyl@ZIF-67 and Xyl@Mn/ZIF-67 have a high potential for juice clarification as an efficient heterogeneous biocatalyst.</p><h3 data-test=\"abstract-sub-heading\">Graphical Abstract</h3>\n","PeriodicalId":801,"journal":{"name":"Topics in Catalysis","volume":"6 1","pages":""},"PeriodicalIF":2.8000,"publicationDate":"2024-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Topics in Catalysis","FirstCategoryId":"92","ListUrlMain":"https://doi.org/10.1007/s11244-023-01898-1","RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"CHEMISTRY, APPLIED","Score":null,"Total":0}
引用次数: 0
Abstract
It has been discovered that metal–organic frameworks (MOFs) have desirable qualities for the immobilization of enzymes, including a high surface area, significant interior pore volumes, and easily changeable pore size. Herein, the xylanase (Xyl) enzyme was immobilized for the first time to two different carrier supports, zeolitic imidazolate framework-67 (ZIF-67) and manganese-doped ZIF-67 (Mn/ZIF-67) by in situ method. The physicochemical characterizations of MOFs with and without Xyl were performed by FT-IR, XRD, SEM, and EDAX techniques. Xyl@ZIF-67 and Xyl@Mn/ZIF-67 were evaluated in terms of optimum temperature, optimum pH, kinetic parameters, thermal stability, reusability as well as juice clarification and compared with free Xyl. Optimum temperature values were 50 °C for Xyl@ZIF-67 and 70 °C for free Xyl and Xyl@Mn/ZIF-67. Optimum pH values for free Xyl, Xyl@ZIF-67, and Xyl@Mn/ZIF-67 were recorded as 6.0, 8.0, and 7.0, respectively. Km values for free Xyl, Xyl@ZIF-67, and Xyl@Mn/ZIF-67 were calculated as 3.139, 5.430, and 0.799 mg/mL, respectively, while Vmax values were calculated as 0.167, 0.226, and 0.062 µmol/min/mL, respectively. The results revealed that in comparison to the free Xyl, Xyl@ZIF-67, and Xyl@Mn/ZIF-67 exhibited more thermal resistance. After incubation at 70 °C for 120 min, the free Xyl remained at 28.7% of the activity, while the Xyl@ZIF-67 and Xyl@Mn/ZIF-67 remained at 85.7% and 40.0%, respectively. Moreover, after eight cycles, the Xyl@ZIF-67 and Xyl@Mn/ZIF-67 retained more than 70% of their initial activity. Further, the transmittance of apple juice was increased from 65.61 to 94.73% and from 77.80 to 84.13%, respectively, when Xyl@ZIF-67 and Xyl@Mn/ZIF-67 were used as biocatalysts. Overall, these findings indicated that the suggested Xyl@ZIF-67 and Xyl@Mn/ZIF-67 have a high potential for juice clarification as an efficient heterogeneous biocatalyst.
期刊介绍：
Topics in Catalysis publishes topical collections in all fields of catalysis which are composed only of invited articles from leading authors. The journal documents today’s emerging and critical trends in all branches of catalysis. Each themed issue is organized by renowned Guest Editors in collaboration with the Editors-in-Chief. Proposals for new topics are welcome and should be submitted directly to the Editors-in-Chief.
The publication of individual uninvited original research articles can be sent to our sister journal Catalysis Letters. This journal aims for rapid publication of high-impact original research articles in all fields of both applied and theoretical catalysis, including heterogeneous, homogeneous and biocatalysis.
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