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Systems-based Saccharomyces cerevisiae strain design for improved squalene synthesis.

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Relation http://ir.cftri.com/14094/
https://doi.org/10.1016/j.bej.2019.04.025
 
Title Systems-based Saccharomyces cerevisiae strain design for improved squalene synthesis.
 
Creator Kalaivani, P.
Punil Kumar, H. N.
Sarma, Mutturi
 
Subject 24 Organic Chemistry
19 Yeast
 
Description Constraint-based flux balance analysis of S. cerevisiae has led to the identification of a novel
gene deletion targets, LYS1 and ADK1, for enhancement of squalene flux. LYS1 deletion
resulted in 2-fold improvement in squalene when compared to reference strain BY4741 with a
maximum yield of 33.1 mg/g DCW. A double mutant of ADK1 and LYS1 genes has increased
the squalene yield to 38 mg/g DW which is 2.38-fold higher over the control strain.
Furthermore, single copies of tHMG1 and POS5 (with mitochondrial signal sequence) genes
have been integrated into this double mutant in order to enhance the precursor pool and the
cofactor regeneration capacity, respectively, for enhanced squalene synthesis. The improved
strain, SK22 has resulted in squalene yield of 65 mg/g DW which is 4-folds higher than the
control strain. Finally, the engineered strain was cultivated in a bioreactor using fed-batch
strategy to improve the titer and productivity of squalene. Exponential feeding (open-loop
strategy) using high residual glucose (~40-60 g/L) has increased the squalene titer to a
maximum of 1.9 g/L with a yield of 0.15 g/g DCW, which is several folds higher than the
shake-flask results. Redirecting the lysine synthesis by external supplementation could
potentially improve squalene flux in S. cerevisiae.
 
Date 2019
 
Type Article
PeerReviewed
 
Format pdf
 
Language en
 
Identifier http://ir.cftri.com/14094/1/Biochemical%20Engineering%20Journal%202019.pdf
Kalaivani, P. and Punil Kumar, H. N. and Sarma, Mutturi (2019) Systems-based Saccharomyces cerevisiae strain design for improved squalene synthesis. Biochemical Engineering Journal, 148. pp. 37-45. ISSN 1369-703X