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Improvement of lactic acid production in Saccharomyces cerevisiae by a deletion of ssb1.
- Source :
-
Journal of industrial microbiology & biotechnology [J Ind Microbiol Biotechnol] 2016 Jan; Vol. 43 (1), pp. 87-96. Date of Electronic Publication: 2015 Dec 11. - Publication Year :
- 2016
-
Abstract
- Polylactic acid (PLA) is an important renewable polymer, but current processes for producing its precursor, lactic acid, suffer from process inefficiencies related to the use of bacterial hosts. Therefore, improving the capacity of Saccharomyces cerevisiae to produce lactic acid is a promising approach to improve industrial production of lactic acid. As one such improvement required, the lactic acid tolerance of yeast must be significantly increased. To enable improved tolerance, we employed an RNAi-mediated genome-wide expression knockdown approach as a means to rapidly identify potential genetic targets. In this approach, several gene knockdown targets were identified which confer increased acid tolerance to S. cerevisiae BY4741, of which knockdown of the ribosome-associated chaperone SSB1 conferred the highest increase (52%). This target was then transferred into a lactic acid-overproducing strain of S. cerevisiae CEN.PK in the form of a knockout and the resulting strain demonstrated up to 33% increased cell growth, 58% increased glucose consumption, and 60% increased L-lactic acid production. As SSB1 contains a close functional homolog SSB2 in yeast, this result was counterintuitive and may point to as-yet-undefined functional differences between SSB1 and SSB2 related to lactic acid production. The final strain produced over 50 g/L of lactic acid in under 60 h of fermentation.
- Subjects :
- Fermentation
Gene Knockdown Techniques
Lactic Acid chemistry
Polyesters
Polymers chemistry
RNA Interference
HSP70 Heat-Shock Proteins deficiency
HSP70 Heat-Shock Proteins genetics
Lactic Acid biosynthesis
Metabolic Engineering
Saccharomyces cerevisiae genetics
Saccharomyces cerevisiae metabolism
Saccharomyces cerevisiae Proteins genetics
Subjects
Details
- Language :
- English
- ISSN :
- 1476-5535
- Volume :
- 43
- Issue :
- 1
- Database :
- MEDLINE
- Journal :
- Journal of industrial microbiology & biotechnology
- Publication Type :
- Academic Journal
- Accession number :
- 26660479
- Full Text :
- https://doi.org/10.1007/s10295-015-1713-7