Table 1.
ERG production using engineered microbial cell factories.
| Host organism | Genetic engineering | ERG production | Medium | Cultivation conditions | Reference |
|---|---|---|---|---|---|
| Aspergillus oryzae | Multicopy integration of EGT1 and EGT2 genes from Neurospora crassa under the amyB promoter | 231.0 ± 1.1 mg·kg−1 solid medium in 120 h | Solid medium containing Nanatsuboshi rice and adenine | 50 mL petri dish at 30 °C | [1] |
| Escherichia coli | BW25113 parent strain (high l‐Cys producer), expression of egtBCDE genes from Mycobacterium smegmatis under the tac promoter on high‐copy, episomal plasmids | 24 ± 4 mg·L−1 in 72 h | M9Y medium supplemented with l‐His, l‐Met, ferric sulfate, and sodium thiosulfate. Induction with IPTG | 50 mL medium in 200 mL Erlenmeyer flask at 30 °C and 200 r.p.m. | [2] |
| Escherichia coli | BW25113 parent strain (high l‐Cys producer), expression of egtABCDE genes from M. smegmatis under the tac promoter, and expression of feedback‐insensitive cysE (T167A), feedback‐insensitive serA (T410stop), and wild‐type ydeE genes from E. coli under the ompA promoter on high‐copy, episomal plasmids, and deletion of the native metJ gene | 1311 ± 275 mg·L−1 in 216 h |
Batch phase – Medium containing glucose, salts, tryptone, yeast extract, l‐Met, and ammonium ferric citrate Fed‐batch phase – A 400 g·L−1 glucose solution was fed (0.65 L), and additional feeding of a solution containing with l‐His, l‐Met, sodium thiosulfate (0.25 L). One time addition of pyridoxine, ammonium ferric citrate, and IPTG |
Fed‐batch fermentation in a 3 L jar fermenter from Sanki Seiki, 30 °C and 490 r.p.m., aeration 1 L·min−1, pH 6.9–7.0 | [3] |
| Saccharomyces cerevisiae | CEN.PK113‐7D parent strain, integration of two copies of the EGT1 gene of N. crassa and the EGT2 gene of Claviceps purpurea under the TEF1 promoter | 598 ± 18 mg·L−1 in 84 h |
Batch phase – 0.5 L Mineral medium supplemented with l‐Arg, l‐His, l‐Met, and pyridoxine Fed‐batch phase – 0.5 L feeding medium contained 415 g/L glucose, salts, vitamins, trace metals, l‐Arg, l‐His, l‐Met, and pyridoxine |
Fed‐batch fermentation in 1 L Sartorius bioreactors, 30 °C and 500 r.p.m., aeration 0.5 L·min−1, pH 5.0 | [4] |
| Yarrowia lipolytica | W29 strain with integrated Cas9 and deletion of ku70, integration of two copies of the EGT1 gene of N. crassa and the EGT2 gene of C. purpurea under the control of the TEFintron and the GPD promoter | 1.63 ± 0.04 g·L−1 in 220 h |
Batch phase – 0.5 L mineral medium supplemented with pyridoxine Fed‐batch phase – 0.5 L feeding medium containing 730 g·L−1 glucose, salts, vitamins, trace metals, pyridoxine |
Fed‐batch fermentation in 1 L Sartorius bioreactors, 30 °C and 800–1200 r.p.m., aeration 0.5–1.0 L·min−1, pH 5.0 | This study |