• Title, Summary, Keyword: chemical immobilization

Search Result 331, Processing Time 0.03 seconds

Immobilization of Xylanase Using a Protein-Inorganic Hybrid System

  • Kumar, Ashok;Patel, Sanjay K.S.;Mardan, Bharat;Pagolu, Raviteja;Lestari, Rowina;Jeong, Seong-Hoon;Kim, Taedoo;Haw, Jung Rim;Kim, Sang-Yong;Kim, In-Won;Lee, Jung-Kul
    • Journal of Microbiology and Biotechnology
    • /
    • v.28 no.4
    • /
    • pp.638-644
    • /
    • 2018
  • In this study, the immobilization of xylanase using a protein-inorganic hybrid nanoflower system was assessed to improve the enzyme properties. The synthesis of hybrid xylanase nanoflowers was very effective at $4^{\circ}C$ for 72 h, using 0.25 mg/ml protein, and efficient immobilization of xylanase was observed, with a maximum encapsulation yield and relative activity of 78.5% and 148%, respectively. Immobilized xylanase showed high residual activity at broad pH and temperature ranges. Using birchwood xylan as a substrate, the $V_{max}$ and $K_m$ values of xylanase nanoflowers were 1.60 mg/ml and $455{\mu}mol/min/mg$ protein, compared with 1.42 mg/ml and $300{\mu}mol/min/mg$ protein, respectively, for the free enzyme. After 5 and 10 cycles of reuse, the xylanase nanoflowers retained 87.5% and 75.8% residual activity, respectively. These results demonstrate that xylanase immobilization using a proteininorganic hybrid nanoflower system is an effective approach for its potential biotechnological applications.

Conducting Polymer-Silica Composites for Immobilization of Enzymes

  • Kwon, Sang-Woon;Jeong, Bo-Ock;Lee, Eun-Hee;Kim, Yong-Shin;Jung, Yong-Ju
    • Bulletin of the Korean Chemical Society
    • /
    • v.33 no.5
    • /
    • pp.1593-1596
    • /
    • 2012
  • A new enzyme immobilization method based on hydrophobic interaction between supporting material and enzyme has been successfully developed. The efficacy of the new technique has been investigated by loading a horse radish peroxidase (HRP) enzyme on the surface of conducting polymer-silica composites and by measuring the enzyme activity and leaching property of HRP loaded within polymer-silica composites. The immobilized HRP enzyme showed activity profiles similar to that of free HRP in phosphate buffer (pH 6). Above all, HRP adsorbed on the polymer-silica composites has showed excellent stability over 10 days, compared to HRP adsorbed on the pristine silica. It is thought that with appropriate optimization works, the present method would be used as a cost-effective and facile route for the immobilization of biomolecules.

Immobilization of Penicillium citrinum by Entrapping Cells in Calcium Alginate for the Production of Neo-Fructooligosaccharides

  • Lim, Jung-Soo;Park, Seung-Won;Lee, Jin-Won;Oh, Kyeong-Keon;Kim, Seung-Wook
    • Journal of Microbiology and Biotechnology
    • /
    • v.15 no.6
    • /
    • pp.1317-1322
    • /
    • 2005
  • This work describes neo-fructooligosaccharides (neo-FOSs) production using the immobilized mycelia of Penicillium citrinum. Some critical factors were evaluated to optimize maximal production of neo-FOS. Optimal alginate and cell concentrations were determined to be $1.96\%$ alginate and $7.17\%$ cell, respectively, by statistical analysis. The optimal concentration of $CaCl_{2}$, which is related to bead stability, was determined to be 2 M. It was possible to increase the neo-FOS production by adding 15 units of glucose oxidase to the batch reaction. By co-immobilizing cells and glucose oxidase, neoFOS productivity increased $123\%$ compared with the whole-cell immobilization process. Based on the results above, a co-immobilization technique was developed and it can be utilized for large-scale production.

Optimization of Lipase Pretreatment Prior to Lipase Immobilization to Prevent Loss of Activity

  • Lee, Dong-Hwan;Kim, Jung-Mo;Shin, Hyun-Yong;Kim, Seung-Woo
    • Journal of Microbiology and Biotechnology
    • /
    • v.17 no.4
    • /
    • pp.650-654
    • /
    • 2007
  • In our previous work, a method of pretreating lipase was developed to prevent loss of its activity during covalent immobilization. In this study, Rhizopus oryzae lipase was pretreated before immobilization and then immobilized on a silica gel surface. The effects of the various materials and conditions used in the pretreatment stage on the activity of immobilized lipase were investigated. Immobilized lipase pretreated with 0.1% of soybean oil had better activity than those pretreated with other materials. The optimal temperature, agitation speed, and pretreating time for lipase pretreatment were determined to be $40^{\circ}C$, 200rpm, and 45min, respectively. The activity of immobilized soybean oil pretreated lipase was 630U/g matrix, which is 20 times higher than that of immobilized non-pretreated lipase. In addition, immobilized lipase activity was maintained at levels exceeding 90% of its original activity after 10 reuses.

Performance of PEG on immobilization of zero valent metallic particles on PVDF membrane for nitrate removal

  • Chan, Yi Shee;Chan, Mieow Kee;Ngien, Su Kong;Chew, Sho Yin;Teng, Yong Kang
    • Membrane Water Treatment
    • /
    • v.9 no.1
    • /
    • pp.1-7
    • /
    • 2018
  • The principal objective of this study is to investigate the effect of Polyethylene Glycol (PEG) crosslinking in Polyvinylidene Fluoride (PVDF) in immobilization of Fe and bimetallic Fe/Cu and Cu/Fe zero valent particles on the membrane and its efficiency on removal of nitrate in wastewater. PVDF/PEG polymer solution of three weight compositions was prepared to manipulate the viscosity of the polymer. PEG crosslinking was indirectly controlled by the viscosity of the polymer solution. In this study, PEG was used as a modifier of PVDF membrane as well as a cross-linker for the immobilization of the zero valent particles. The result demonstrates improvement in immobilization of metallic particles with the increase in crosslinking of PEG. Nitrate removal efficiency increases too.

Gellan Gum as Immobilization Matrix for Production of Cyclosporin A

  • Survase, Shrikant A.;Annapure, Uday S.;Singhal, Rekha S.
    • Journal of Microbiology and Biotechnology
    • /
    • v.20 no.7
    • /
    • pp.1086-1091
    • /
    • 2010
  • This study explored the use of gellan gum as an immobilization matrix for the production of cyclosporin A (CyA) by immobilized spores and mycelia of Tolypocladium inflatum MTCC 557. Different carriers, such as gellan gum, sodium alginate, celite beads, and silica, were tested as immobilization carriers, along with the role of the carrier concentration, biomass weight, number of spore-inoculated beads, and repeated utilization of the immobilized fungus. The maximum CyA production was 274 mg/l when using gellan gum [1% (w/v)], and a mycelial weight of 7.5% (w/v) supported the maximum production of CyA. Additionally, the addition of a combination of $_L$-valine (6 g/l) and $_L$-leucine (5 g/l) after 48 h of fermentation produced 1,338 mg/l of CyA when using gellan gum. The immobilized mycelia beads were found to remain stable for four repetitive cycles, indicating their potential for semicontinuous CyA production.

Immobilization of MTBE using cyclodextrins

  • Baek, Ki-Tae;Yang, Ji-Won
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
    • /
    • /
    • pp.120-123
    • /
    • 2003
  • Immobilization behavior of methyl tert-butyl ether (MTBE) by various cyclodextrins(CDs) was studied to investigate the feasibility of MTBE removal using cyclodexrins. Even though MTBE has relatively low hydrophobicity and higher polarity compared to other organics, it was effectively immobilized by CDs. The immobilization isotherms was shown as a type of Freundlich isotherms, and the immobilization capacity of -CDs was the largest among natural COs. The initial apparent association constant for MTBE-CD complex follows the order : gamma = beta > methyl-beta > hydroxypropyl beta > alpha. These differences of the constants are related to the size of MTBE and CDs. The size of beta-CD and gamma-CD is large to encapsulate MTBE molecule into the cavity, which that of alpha-CB is too small to encapsulate MTBE.

  • PDF