Improving acetyl-CoA biosynthesis in via the overexpression of pantothenate kinase and PDH bypass.

BACKGROUND

Acetyl-CoA is an important precursor in . Various approaches have been adopted to improve its cytosolic level previously with the emphasis on engineering the "acetyl-" part of acetyl-CoA. To the best of our knowledge, there have been no reports on engineering the "-CoA" part so far.

RESULTS

In this study, we had tried to engineer from both the "-CoA" part via pantothenate kinase overexpression (PanK from , the rate-limiting enzyme for CoA synthesis) and the "acetyl-"part through PDH bypass introduction ( from and Se from ). A naringenin-producing reporter strain had been constructed to reflect cytosolic acetyl-CoA level as acetyl-CoA is the precursor of naringenin. It was found that PanK overexpression or PDH bypass introduction alone only led to a twofold or 6.74-fold increase in naringenin titer, but the combination of both (strain CENFPAA01) had resulted in 24.4-fold increase as compared to the control (strain CENF09) in the presence of 0.5 mM substrate -coumaric acid. The supplement of PanK substrate pantothenate resulted in another 19% increase in naringenin production.

CONCLUSIONS

To greatly enhance acetyl-CoA level in yeast cytosol, it is feasible to engineer both the "acetyl-" part and the "-CoA" part simultaneously. Insufficient CoA supply might aggravate acetyl-CoA shortage and cause low yield of target product.