Open AccessProtease‐deficient mutants of the Quorn® mycoprotein fungus, Fusarium graminearum A3/5
Author(s) -
Griffen Alison M,
Novakova Michaela,
Mokhtar Seri I,
Wiebe Marilyn G,
Robson Geoffrey D,
Trinci Anthony P.J
Publication year - 1998
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1998.tb12825.x
Subject(s) - protease , chemostat , mutant , proteases , microbiology and biotechnology , biology , biochemistry , casein , enzyme , bacteria , genetics , gene
Protease‐deficient mutants of two highly branched (colonial) mutants of the Quorn® mycoprotein fungus, Fusarium graminearum A3/5, were generated by UV mutagenesis. One protease‐deficient mutant of each strain was studied in glucose‐limited chemostat culture ( D = 0.17 h −1 , pH=5.8) with 5 g casein l −1 added to the medium and they were found to produce no or very little aspartic protease, which is produced by the parental strains under the same conditions. In chemostat culture the protease‐deficient mutants were unstable with respect to lack of proteolytic activity regardless of whether or not casein (500 mg l −1 ) was included in the medium. At low dilution rate ( D = 0.07 h −1 ) or at increased pH (pH=6.9), the parental strains produced other proteases in addition to the aspartic protease.