Non-revertible β-oxidation blocked
View Patent ↗Genetically modified strains of C. tropicalis , which will not revert to wild-type activity at the POX 4 and/or POX 5 locus, are disclosed. The strains are β-oxidation blocked and have been transformed through homologous recombination with a construct which deletes a portion of the POX 4 and/or POX 5 gene. The modified strains may be used to increase yields of dicarboxylic acids produced in host cells of the strains. Methods for blocking the β-oxidation pathway in a C. tropicalis host cell are also provided.
1. A Candida tropicalis cell derived from Candida tropicalis strain H53 by deletion of a 653 base pair portion of a coding region of a POX 4 gene open reading frame of strain H53 and insertion of a 1676 base pair URA 3 marker gene in the POX 4 coding region, wherein the cell is a cell of strain HDC100.
2. A process for producing a substantially pure α,ω-dicarboxylic acid which comprises culturing the Candida tropicalis cell of claim 1 in a culture medium containing a nitrogen source, an organic substrate and a cosubstrate.
3. A Candida tropicalis cell of strain HDC100.
4. A process for producing a substantially pure α,ω-dicarboxylic acid which comprises culturing the Candida tropicalis cell of claim 3 in a culture medium containing a nitrogen source, an organic substrate and a cosubstrate.
5. A Candida tropicalis cell of strain HDC100 deposited under Accession No. DSM19688.
6. A process for producing a substantially pure α,ω-dicarboxylic acid which comprises culturing the Candida tropicalis cell of claim 5 in a culture medium containing a nitrogen source, an organic substrate and a cosubstrate.