Yazar "Erol, Kadir" seçeneğine göre listele

Listeleniyor 1 - 2 / 2
  • [ X ]
    Öğe
    Antimicrobial magnetic poly(GMA) microparticles: synthesis, characterization and lysozyme immobilization
    (Walter De Gruyter Gmbh, 2021) Erol, Kadir; Tatar, Demet; Veyisoglu, Aysel; Tokatli, Ali
    Micron-sized magnetic particles currently find a wide range of applications in many areas including biotechnology, biochemistry, colloid sciences and medicine. In this study, magnetic poly(glycidyl methacrylate) microparticles were synthesized by providing a polymerization around Fe(II)-Ni(II) magnetic double salt. Adsorption of lysozyme protein from aqueous systems was studied with these particles. Adsorption studies were performed with changing pH values, variable amount of adsorbent, different interaction times and lysozyme amounts. The adsorption capacity of the particles was investigated, and a value of about 95.6 mg lysozyme/g microparticle was obtained. The enzyme activity of the immobilized lysozyme was examined and found to be more stable and reusable compared to the free enzyme. The immobilized enzyme still showed 80% activity after five runs and managed to maintain 78% of its initial activity at the end of 60 days. Besides, in the antimicrobial analysis study for six different microorganisms, the minimum inhibitory concentration value of lysozyme immobilized particles was calculated as 125 tg/mL like free lysozyme. Finally, the adsorption interaction was found to be compatible with the Langmuir isotherm model. Accordingly, it can be said that magnetic poly(GMA) microparticles are suitable materials for lysozyme immobilization and immobilized lysozyme can be used in biotechnological studies.
  • [ X ]
    Öğe
    Enhanced kinetic performance and stability of catalase immobilized on epoxy-functionalized kaolinite
    (Nature Portfolio, 2026) Erol, Kadir; Veyisoglu, Aysel; Tatar, Demet; Kocabas, Buket Bulut; Alacabey, Ihsan; Gokmese, Ebru
    The immobilization of catalase onto stable, reusable supports is crucial for efficient peroxide-based biocatalytic applications. In this study, catalase was immobilized for the first time onto epoxy-functionalized kaolinite particles prepared via surface silanization with (3-glycidyloxypropyl)trimethoxysilane. Structural and surface characterizations confirmed successful organosilane grafting while preserving the layered kaolinite framework. The modified support exhibited rapid enzyme uptake and a high immobilization capacity of approximately 300 mg g(-1). Kinetic analysis showed a substantial decrease in K-m from 57.3 mM (free catalase) to 21.6 mM after immobilization, indicating enhanced substrate affinity. In contrast, V-max decreased due to diffusion limitations typical of heterogeneous systems. Despite this, catalytic efficiency increased nearly 1.8-fold. Moreover, immobilized catalase demonstrated significantly improved operational reusability and long-term storage stability compared to the free enzyme. These results highlight silanized kaolinite as a robust, low-cost, and efficient mineral-based support for catalase immobilization, with strong potential for environmental and industrial biocatalytic applications.