title: Combined effect of improved cell yield and increased specific productivity enhances recombinant enzyme production in genome-reduced Bacillus subtilis strain MGB874.
abstract: Genome reduction strategies to create genetically improved cellular biosynthesis machineries for proteins and other products have been pursued by use of a wide range of bacteria. We reported previously that the novel Bacillus subtilis strain MGB874, which was derived from strain 168 and has a total genomic deletion of 874 kb (20.7%), exhibits enhanced production of recombinant enzymes. However, it was not clear how the genomic reduction resulted in elevated enzyme production. Here we report that deletion of the rocDEF-rocR region, which is involved in arginine degradation, contributes to enhanced enzyme production in strain MGB874. Deletion of the rocDEF-rocR region caused drastic changes in glutamate metabolism, leading to improved cell yields with maintenance of enzyme productivity. Notably, the specific enzyme productivity was higher in the reduced-genome strain, with or without the rocDEF-rocR region, than in wild-type strain 168. The high specific productivity in strain MGB874 is likely attributable to the higher expression levels of the target gene resulting from an increased promoter activity and plasmid copy number. Thus, the combined effects of the improved cell yield by deletion of the rocDEF-rocR region and the increased specific productivity by deletion of another gene(s) or the genomic reduction itself enhanced the production of recombinant enzymes in MGB874. Our findings represent a good starting point for the further improvement of B. subtilis reduced-genome strains as cell factories for the production of heterologous enzymes.
authors.affiliation: Biological Science Laboratories, Kao Corporation, 2606 Akabane, Ichikai, Haga, Tochigi 321-3497, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Manabe
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Kageyama
authors.forename: Takuya
authors.initials: T
authors.lastname: Morimoto
authors.forename: Tadahiro
authors.initials: T
authors.lastname: Ozawa
authors.forename: Kazuhisa
authors.initials: K
authors.lastname: Sawada
authors.forename: Keiji
authors.initials: K
authors.lastname: Endo
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Tohata
authors.forename: Katsutoshi
authors.initials: K
authors.lastname: Ara
authors.forename: Katsuya
authors.initials: K
authors.lastname: Ozaki
authors.forename: Naotake
authors.initials: N
authors.lastname: Ogasawara
mesh_terms: D001412:Bacillus subtilis / Q000235:genetics* / Q000378:metabolism*; D004798:Enzymes / Q000096:biosynthesis* / Q000235:genetics*; D018628:Gene Dosage; D016680:Genome, Bacterial; D018698:Glutamic Acid / Q000378:metabolism; D010957:Plasmids; D011401:Promoter Regions, Genetic; D011994:Recombinant Proteins / Q000096:biosynthesis* / Q000235:genetics*; D017384:Sequence Deletion
chemical_list: D004798:Enzymes; D011994:Recombinant Proteins; D018698:Glutamic Acid