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Expression of Aspergillus hemoglobin domain activities in Aspergillus oryzae grown on solid substrates improves growth rate and enzyme production
Author(s) -
te Biesebeke Rob,
Boussier Amandine,
van Biezen Nick,
Braaksma Machtelt,
van den Hondel Cees A. M. J. J.,
de Vos Willem M.,
Punt Peter J.
Publication year - 2006
Publication title -
biotechnology journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.144
H-Index - 84
eISSN - 1860-7314
pISSN - 1860-6768
DOI - 10.1002/biot.200600036
Subject(s) - aspergillus oryzae , aspergillus niger , aspergillus , biology , protease , gene , enzyme , biochemistry , amylase , strain (injury) , gene expression , microbiology and biotechnology , food science , chemistry , anatomy
DNA fragments coding for hemoglobin domains (HBD) were isolated from Aspergillus oryzae and Aspergillus niger. The HBD activities were expressed in A. oryzae by introduction of HBD gene fragments under the control of the promoter of the constitutively expressed gpdA gene. In the transformants, oxygen uptake was significantly higher, and during growth on solid substrates the developed biomass was at least 1.3 times higher than that of the untransformed wild‐type strain. Growth rate of the HBD‐activity‐producing strains was also significantly higher compared to the wild type. During growth on solid cereal substrates, the amylase and protease activities in the extracts of the HBD‐activity‐producing strains were 30–150% higher and glucoamylase activities were at least 9 times higher compared to the wild‐type strain. These results suggest that the Aspergillus HBD‐encoding gene can be used in a self‐cloning strategy to improve biomass yield and protein production of Aspergillus species.