Effective lead selection for improved protein production in Aspergillus niger based on integrated genomics.
The filamentous fungus Aspergillus niger is widely exploited for industrial production of enzymes and organic acids. An integrated genomics approach was developed to determine cellular responses of A. niger to protein production in well-controlled fermentations. Different protein extraction methods in combination with automated sample processing and protein identification allowed quantitative analysis of 898 proteins. Three different enzyme overproducing strains were compared to their isogenic fungal host strains. Clear differences in response to the amount and nature of the overproduced enzymes were observed. The corresponding genes of the differentially expressed proteins were studied using transcriptomics. Genes that were up-regulated both at the proteome and transcriptome level were selected as leads for generic strain improvement. Up-regulated proteins included proteins involved in carbon and nitrogen metabolism as well as (oxidative) stress response, and proteins involved in protein folding and endoplasmic reticulum-associated degradation (ERAD). Reduction of protein degradation through the removal of the ERAD factor doaA combined with overexpression of the oligosaccharyl transferase sttC in A. niger overproducing beta-glucuronidase (GUS) strains indeed resulted in a small increase in GUS expression.
Jacobs
Denise I
DI
DSM Food Specialties, PO Box 1, NL-2600 MA Delft, The Netherlands.
Olsthoorn
Maurien M A
MM
Maillet
Isabelle
I
Akeroyd
Michiel
M
Breestraat
Stefaan
S
Donkers
Serge
S
van der Hoeven
Rob A M
RA
van den Hondel
Cees A M J J
CA
Kooistra
Rolf
R
Lapointe
Thomas
T
Menke
Hildegard
H
Meulenberg
Rogier
R
Misset
Marijke
M
Müller
Wally H
WH
van Peij
Noël N M E
NN
Ram
Arthur
A
Rodriguez
Sabrina
S
Roelofs
Marc S
MS
Roubos
Johannes A
JA
van Tilborg
Marcel W E M
MW
Verkleij
Arie J
AJ
Pel
Herman J
HJ
Stam
Hein
H
Sagt
Cees M J
CM
D001234:Aspergillus niger / Q000235:genetics* / Q000378:metabolism*; D005656:Fungal Proteins / Q000096:biosynthesis* / Q000235:genetics*; D020869:Gene Expression Profiling; D023281:Genomics; D005966:Glucuronidase / Q000096:biosynthesis / Q000235:genetics; D007218:Industrial Microbiology; D020543:Proteome / Q000032:analysis
D005656:Fungal Proteins; D020543:Proteome; D005966:Glucuronidase