Table 1 Overview of metabolic engineering studies on the production of trans-4-hydroxy-l-proline by microbial cells

E. coli

pTr2-4OH

(1) + Da-p4h^o; (2) promoters^o; and (3)ΔputA;

41

Batch, 5 L (glucose + proline)

[58]

E. coli

pSTV29

(1) + Da-p4h; (2) + proB*; (3) + proA; and (4)ΔputA

25

Batch, 5 L (glucose)

[38]

E. coli and C. glutamicum

pET28a

Compared with the Ps-p4h and Bo-p4h, and Da-p4h

2.28 or 6.72

Batch, 250 mL(glucose) or Batch, 250 mL (glucose + proline)

[19]

C. glutamicum

pEKEx2

 + p4h

7.1

Fed-batch, 3 L (glucose + isoleucine)

[70]

E. coli

pUC19

(1) + Da-p4h^o; (2) expression vectors^o;

25.4

Fed-batch, 5 L (glycerol + proline)

[81]

E. coli

pTrc99a

(1) + Da-p4h; and (2) + VHb

14.4

Fed-batch, 1.4 L (glucose + proline)

[75]

E. coli

pTrc99a

(1) + Da-p4h; (2)ΔsucAB; (3)ΔaceAK; (4)ΔputA; and (5) + proB*; and (6) + proA gene

31

Fed-batch, 5 L (glucose)

[67]

E. coli

pTc

(1) + p4h^gm; (2)ΔputA; (3) + proB*; and (4) + proA

45.83

Fed-batch, 5 L (glucose)

[55]

C. glutamicum

pXMJ19

(1) + Da-p4h; (2)ΔsucCD; and (3) fine-tuning of proB* and p4h abundances

21.72

Fed-batch, 500 mL (glucose)

[62]

E. coli

pET21a

(1) + Un-p4h; (2) + p4h^re; (3) p4h*; (4)ΔputA; (5) + proB*; and (6) + proA

12.9

Fed-batch, 5 L (glucose)

[57]

E. coli

pDXW-10

(1) + p4h^rd; (2) + p4h^o; (3)ΔputA; (4)ΔproP; (5)ΔputP; (6)ΔaceA; (7) + proB*; and (8) a tunable circuit based on quorum sensing

54.8

Fed-batch, 7.5 L (glucose)

[69]