COVALENT IMMOBILIZATION OF ASPERGILLUS-NIGER ON PHEMA MEMBRANE - APPLICATION TO CONTINUOUS-FLOW REACTORS


ARICA M., SHARIF F., ALAEDDINOGLU N., HASIRCI N., HASIRCI V.

JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY, vol.58, no.3, pp.281-285, 1993 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 58 Issue: 3
  • Publication Date: 1993
  • Doi Number: 10.1002/jctb.280580312
  • Journal Name: JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Aerospace Database, Agricultural & Environmental Science Database, Applied Science & Technology Source, Aqualine, Aquatic Science & Fisheries Abstracts (ASFA), BIOSIS, Biotechnology Research Abstracts, CAB Abstracts, Chemical Abstracts Core, Chimica, Communication Abstracts, Compendex, Computer & Applied Sciences, EMBASE, Food Science & Technology Abstracts, INSPEC, Metadex, Pollution Abstracts, Veterinary Science Database, Civil Engineering Abstracts
  • Page Numbers: pp.281-285
  • Middle East Technical University Affiliated: Yes

Abstract

Poly(2-hydroxyethyl methacrylate) (pHEMA) membrane was prepared via photopolymerization and activated with epichlorohydrin. The conidia of Aspergillus niger strains (wild type 'NRRL-3' and genetically improved strain 'NRRL-3/2-2A') were covalently-immobilized on the membranes. Uniform growth of A. niger cells on membrane surfaces was verified by SEM. The glucose oxidase (GOD) activity of the immobilized cells was determined in a continuous flow membrane reactor (CFMR) by assaying for hydrogen peroxide produced. The activity was also determined in the culture fluids of A. niger strains, freely grown in batch cultures. The CFMR was run with 0.1 mol dm-3 glucose with a fixed flow rate of 20 cm3 h-1 for 60 h during which a 10% loss of the original activity was detected. The loss of the activity with the freely cultivated mycelia was about 50% after 30 h. The GOD activity of the improved strain NRRL-3/2-2A was about 20 times higher whether in immobilized or in free form. The GOD activity of the immobilized A. niger strains in the continuous flow membrane reactor was found to be 2-5 times better than their counterparts freely grown in batch cultures indicating that immobilization increases the activity and the stability of the microorganisms.