[Construction of recipient strain of expression-secretion system in filamentous fungi].
Glucoamylase overproducing A. niger T21 was mutated by UV mutagensis. An extracellular acid protease-deficient mutant, A. niger T21-201, which produced only 0.76% extracellular acid protease activity of the parent strain, was screened by casein-degradating plate and determination of protease activity. Moreover, the growth properties and the ability to secrete glucoamylase of A. niger T21-201 are identical to these of starting strain T21. The comparison of expression-secretion levels of heterologous gene in A. niger T21-201 and T21 was carried out with bacterial vhb as reporter, the level of expression-secretion of VHb in A. niger T21-201 was 6-7 times higher than that in T21, but the transcriptional levels of vhb gene in both strains were similar revealed by Northern blot. Therefore, it was demonstrated that the deficiency of acid protease of recipient T21-201 has significant effect on the protection of heterologous protein.
Liu
Li
L
Institute of Microbiology, China Academy of Sciences, Beijing 100080, China.
Liu
Jin
J
Qiu
Run-Xiang
RX
Zhu
Xing-Guo
XG
Tang
Guo-Min
GM
D001234:Aspergillus niger / Q000201:enzymology / Q000235:genetics*; D005087:Glucan 1,4-alpha-Glucosidase / Q000096:biosynthesis* / Q000235:genetics; D009154:Mutation; D011994:Recombinant Proteins / Q000096:biosynthesis*
D011994:Recombinant Proteins; D005087:Glucan 1,4-alpha-Glucosidase