Cell surface display of a β-glucosidase employing the type V secretion system on ethanologenic Escherichia coli for the fermentation of cellobiose to ethanol.
We used the autodisplay system AIDA-I, which belongs to the type V secretion system (TVSS), to display the β-glucosidase BglC from Thermobifida fusca on the outer membrane of the ethanologenic Escherichia coli strain MS04 (MG1655 ∆pflB, ∆adhE, ∆frdA, ∆xylFGH, ∆ldhA, PpflB::pdc (Zm)-adhB (Zm)). MS04 that was transformed with the plasmid pAIDABglCRHis showed cellobiase activity (171 U/g(CDW)) and fermented 40 g/l cellobiose in mineral medium in 60 h with an ethanol yield of 81 % of the theoretical maximum. Whole-cell protease treatment, SDS-PAGE, and Western-blot analysis demonstrated that BglC was attached to the external surface of the outer membrane of MS04. When attached to the cells, BglC showed 93.3 % relative activity in the presence of 40 g/l ethanol and retained 100 % of its activity following 2 days of incubation at 37 °C with the same ethanol concentration. This study shows the potential of the TVSS (AIDA-I) and BglC as tools for the production of lignocellulosic bio-commodities.
Departamento de Ingeniería Celular y Biocatálisis, Instituto de Biotecnología, Universidad Nacional Autónoma de México, A. P. 510-3, 62250, Cuernavaca, Morelos, Mexico.
Iván
I
Muñoz-Gutiérrez
Ricardo
R
Oropeza
Guillermo
G
Gosset
Alfredo
A
Martinez
D000192:Actinomycetales / Q000201:enzymology / Q000235:genetics; D058947:Bacterial Secretion Systems; D002475:Cellobiose / Q000378:metabolism*; D044602:Cellulases / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000166:cytology / Q000235:genetics / Q000378:metabolism*; D000431:Ethanol / Q000378:metabolism*; D005285:Fermentation; D001617:beta-Glucosidase / Q000235:genetics / Q000378:metabolism*
D058947:Bacterial Secretion Systems; D002475:Cellobiose; D000431:Ethanol; D044602:Cellulases; D001617:beta-Glucosidase