Yazar "Alaeddinoglu, G" seçeneğine göre listele

Listeleniyor 1 - 2 / 2
  • Küçük Resim
    Öğe
    Affinity interaction of hydroxypyruvate reductase from Methylophilus spp. with Cibacron blue F3GA-derived poly(HEMA EGDMA) microspheres: partial purification and characterization
    (Elsevier Sci Ltd, 1999) Arica, MY; Halicigil, C; Alaeddinoglu, G; Denizli, A
    A methylotrophic hydroxypyruvate reductase was partially purified and characterized from Methylophilus spp. using the biomimetic dye, Cibacron Blue F3FA attached to poly(HEMA-EGDMA) microspheres. The absorption capacities of the dye-affinity microspheres were determined by changing pH and the concentration of the proteins in the adsorption medium. Hydroxypyruvate reductase was desorbed from the dye-affinity support specifically with 2 mM NADH solution. The enzyme was purified 10.4-fold with 47% yield. The molecular mass and subunit molecular mass of the enzyme was estimated to be 75 kDa and 37 kDa on the basis of its mobility in polyacrylamide and SDS-polyacrylamide gels, respectively. This suggested a homogeneous dimer structure. The optimal pH was between 5.0 and 7.0, and the maximum enzyme activity was obtained at 50 degrees C. The K-m values of hydroxpyruvate reductase were 0.222 mM for hydroxpyruvate and 0.067 mM for NADH. (C) 1999 Elsevier Science Ltd. All rights reserved.
  • Küçük Resim
    Öğe
    Controlled release of aldicarb from lignin loaded ionotropic hydrogel microspheres
    (Taylor & Francis Ltd, 1999) Kok, FN; Wilkins, RM; Cain, RB; Arica, MY; Alaeddinoglu, G; Hasirci, V
    Aldicarb loaded microspheres of carboxymethyl cellulose, CMC, of various compositions were prepared with the crosslinking action of AI(III). Into these microspheres, lignin was introduced as a filler to further regulate the rate of release. The encapsulation efficiency was low (4.15-13.00%) due to the high water solubility of aldicarb. Release into aqueous media was quite rapid and almost complete within 24h. Initial stages of the release (60% of AS released) was investigated to determine the release mechanism and it was found that release from the microspheres was governed by Fickian diffusion. Among the various parameters, the ratio of lignin to CMC and aldicarb to CMC were found to be influential on the rate of release from the crosslinked CMC-lignin microspheres. The soil behaviour confirmed the delayed release effect of the controlled release formulation compared to Temik (a commercial preparation of aldicarb), especially when lignin was incorporated.