Optimization of the benzoate-inducible benzoate p-hydroxylase cytochrome P450 enzyme system in Aspergillus niger

Introduction in the fungus Aspergillus niger of multiple copies of the A. niger bphA gene, encoding the cytochrome P450 enzyme benzoate p-hydroxylase, did not result in increased activities of this enzyme [Gorcom RFM van, et al. Mol Gen Genet (1990) 223: 192-197] probably because of low expression l...

Full description

Saved in:
Bibliographic Details
Published in:Applied microbiology and biotechnology 1996-11, Vol.46 (4), p.360-364
Main Authors: Brink, J.M. van den, Hondel, C.A.M.J.J. van den, Gorcom, R.F.M. van
Format: Article
Language:English
Subjects:
Aspergillus niger - enzymology
Aspergillus niger - genetics
Benzoates - pharmacology
Benzoic Acid
Biological and medical sciences
Biotechnology
Fundamental and applied biological sciences. Psychology
Gene Dosage
Gene Expression Regulation, Fungal - drug effects
Genes, Fungal - genetics
Genetic engineering
Genetic technics
Methods. Procedures. Technologies
Microsomes - enzymology
Molecular cloning
NADH, NADPH Oxidoreductases - genetics
NADH, NADPH Oxidoreductases - metabolism
NADPH-Ferrihemoprotein Reductase
Oxygenases - genetics
plant biochemistry
plant breeding
plant genetics
plant physiology
Transformation, Genetic
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Introduction in the fungus Aspergillus niger of multiple copies of the A. niger bphA gene, encoding the cytochrome P450 enzyme benzoate p-hydroxylase, did not result in increased activities of this enzyme [Gorcom RFM van, et al. Mol Gen Genet (1990) 223: 192-197] probably because of low expression levels of the gene encoding the second component of the microsomal cytochrome P450 enzyme system, cytochrome P450 reductase. For improvement of this and other cytochrome-P450-dependent reactions, A. niger strains were constructed in which the copy number of the A. niger cprA gene (encoding cytochrome-P450 reductase) or the copy numbers of both cprA and the cytochrome-P450-encoding gene were increased. Expression of both genes was controlled by their own transcription control regions. Benzoate p-hydroxylase activity of different transformants was determined in microsomal fractions using a newly developed indirect in vitro assay. In transformants containing multiple copies of both genes, benzoate p-hydroxylase activity was significantly higher than in the wild-type strain or in transformants in which the copy number of only one of the genes was increased. These results clearly indicate the importance of co-expression of cytochrome-P450 reductase for achieving maximal cytochrome P450 activities in cytochrome-P450-overproducing filamentous fungi.
ISSN:0175-7598
1432-0614
DOI:10.1007/BF00166230