Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Comparative Study
. 1993 Jan-Feb;38(1-2):69-81.
doi: 10.1007/BF02916413.

Immobilization of Aspergillus niger NRC 107 Xylanase and beta-Xylosidase, and Properties of the Immobilzed Enzymes

M A Abdel-Naby  1
Affiliations
Comparative Study

Immobilization of Aspergillus niger NRC 107 Xylanase and beta-Xylosidase, and Properties of the Immobilzed Enzymes

M A Abdel-Naby. Appl Biochem Biotechnol. 1993 Jan-Feb.

Abstract

Aspergillus niger NRC 107 xylanase and beta-xylosidase were immobilized on various carriers by different methods of immobilization, including physical absorption, covalent binding, ionic binding, and entrapment. The immobilized enzymes were prepared by physical adsorption on tannin-chitosan, ionic binding onto Dowex-50W, covalent binding on chitosan beads through glutaraldehyde, and entrapment in polyacrylamide had the highest activities. In most cases, the optimum pH of the immobilized enzymes were shifted to lower than those of free enzymes. The optimum reaction temperature of immobilized xylanase was shifted from 50C to 52.5-65C, whereas that of immobilized beta-xylosidase was shifted from 45C to 50-60C. The Km values of immobilized enzymes were higher than those of native enzymes. The operational stability of the immobilized enzymes was evaluated in continuous operation in packed-bead column-type reactors. The enzymes covalently bounded to chitosan showed the highest operational stability. However, the enzymes immobilized by physical absorption or by ionic binding showed a low operational stability. The enzymes entrapped in polyacrylamide exhibited lower activity, but better operational stability.

PubMed Disclaimer

References

    1. J Biochem. 1979 Apr;85(4):1091-8 - PubMed
    1. Appl Environ Microbiol. 1985 Oct;50(4):924-9 - PubMed
    1. J Chem Technol Biotechnol. 1990;48(2):185-200 - PubMed
    1. Biochem Biophys Res Commun. 1973 Jun 8;52(3):905-12 - PubMed
    1. J Biol Chem. 1952 Mar;195(1):19-23 - PubMed

Publication types