Knocking out the MFE-2 gene of Candida bombicola leads to improved medium-chain sophorolipid production.
FEMS Yeast Res
; 9(4): 610-7, 2009 Jun.
Article
in En
| MEDLINE
| ID: mdl-19416371
ABSTRACT
The nonpathogenic yeast Candida bombicola synthesizes sophorolipids. These biosurfactants are composed of the disaccharide sophorose linked to a long-chain hydroxy fatty acid and have potential applications in the food, pharmaceutical, cosmetic and cleaning industries. In order to expand the range of application, a shift of the fatty acid moiety towards medium-chain lengths would be recommendable. However, the synthesis of medium-chain sophorolipids by C. bombicola is a challenging objective. First of all, these sophorolipids can only be obtained by fermentations on unconventional carbon sources, which often have a toxic effect on the cells. Furthermore, medium-chain substrates are partially metabolized in the beta-oxidation pathway. In order to redirect unconventional substrates towards sophorolipid synthesis, the beta-oxidation pathway was blocked on the genome level by knocking out the multifunctional enzyme type 2 (MFE-2) gene. The total gene sequence of the C. bombicola MFE-2 (6033 bp) was cloned (GenBank accession number EU371724), and the obtained nucleotide sequence was used to construct a knock-out cassette. Several knock-out mutants with the correct geno- and phenotype were evaluated in a fermentation on 1-dodecanol. All mutants showed a 1.7-2.9 times higher production of sophorolipids, indicating that in those strains the substrate is redirected towards the sophorolipid synthesis.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Candida
/
Fungal Proteins
/
Glycolipids
/
Gene Knockout Techniques
Language:
En
Journal:
FEMS Yeast Res
Journal subject:
MICROBIOLOGIA
Year:
2009
Document type:
Article
Affiliation country:
Belgium