Table 6 Engineered strains of H. bluephagenesis TD01

TD04

TD01

Deletion of prpC gene

CDW of 8.9 g/L containing 70.12% (wt) of P(3HB-co-12.03 mol% 3HV) in presence of 0.5 g/L of propionic acid

Shake flasks

[98]

TD-prpC6prpC7

TD01

Controlled repression of prpC gene using CRISPRi systems

Improved CDW of 14.67 g/L containing 73.78% (wt) P(3HB-co-12.70 mol% 3HV) using 1.0 g/L of propionic acid as co-substrate

Shake flasks

[110]

TD08

TD04

Deletion of three phaZ genes

CDW of 80 g/L containing 70% (wt) of P(3HB-co-8 mol% 3HV) in 0.5 g/L of propionic acid

500-L fermentor

[98]

TD08 (pSEVA341-thrACBilvA)

TD08

Overexpression of thrACB operon and ilvA gene

Synthesis of PHBV with 3HV up to 6 mol% without using 3HV precursor

Shake flasks

[111]

TD08AB

TD08

Chromosomal expression of E. coli scpA-argK-scpB fragment

CDW of 54 g/L containing 57% (wt) P(3HB-co-8 mol% 3HV)

6-L fermentor

[122]

TD08AB (ΔsdhEΔicl)

TD08AB

Deletion of sdhE and icl genes

78% increase in 3HV yield

Shake flasks

[25]

TY194(ΔsdhEΔicl)

TD1.0(ΔprpC)

Integration of scpAB under the control of a P_porin promoter;

deletion of sdhE and icl genes

PHBV with 18 mol% 3HV content in presence of waste gluconate and glucose

Shake flasks

[25]

TY194 (ΔsdhE, G7::P_porin-ppc)

TY194 (ΔsdhE)

Integration of ppc and vgb genes under the control of P_porin and P_8vgb promoter

PHBV with 25 mol% 3HV from glucose and gluconate

Shake flasks

[25]

TD40

TD01

Integration of orfZ gene of Clostridium kluyveri

Block co-polymer of P3HB4HB with 16 mol% 4HB using GBL as co-substrate

1000-L fermentor

[126]

TDH4

TD01

orfZ expression using moderate promoter

4HB mol% similar to TD40 was achieved by consuming 17% less GBL

7-L fermentor

[127]

TDH5

TD01

orfZ expression using strong promoter

40% higher 4HB mol% than TD40 was achieved from GBL as co-substrate

7-L fermentor

[127]

TDH4-pCD-ΔphaP1

TDH4

Deletion of phaP1 and overexpression of minCD

Synthesis of large P3HB4HB granules of axial length 4 µm from GBL as co-substrate

Shake flasks

[116]

TDWT-D2

TD01

Introduction of double plasmid for expression of orfZ, ogdA, sucD, and 4hbd genes

Incorporation of 0.17 mol% 4HB solely from glucose

Shake flasks

[128]

TD△gabD2-D2

TDWT-D2

Deletion of gabD2 and gabD3

Incorporation of up to 24.9 mol% 4HB

7-L fermentor

[128]

TD68-194

TDG (gabD2 and gabD3 deleted TD01 derivative)

Chromosomal integration of the orfZ and 4hbd-sucD-ogdA genes using HRCGE system

Best 4HB-producing strain with 48.2 g/L CDW containing 75% (wt) P(3HB-co-16 mol% 4HB) solely from glucose

7-L fermentor

[26]

TD08 (pRE112-pMB1-udhA)

TD08

Overexpression of udhA

CDW of 12 g/L containing 92% (wt) PHB

Shake flasks

[98]

TD01PC

TD01

Deletion of phaC gene and integration of the phaC_Re downstream of the porin operon

12% increase in PHB yield

Shake flasks

[133]

TDPIΔC (pSEVA341-phaC _Re)

TD01ΔphaC

Plasmid expression of phaC_Re using inducible promoter

PHB content up to 81% (wt)

Shake flasks

[133]

TDPI (pBBR1-Ppolac-phaCAB)

TDPI (TD01 derivative with lacI gene inserted downstream of the porin operon)

Plasmid expression of phaCAB_Re using inducible promoter

Increased PHB concentration up to 7 g/L

Shake flasks

[134]

TD-HIGH

TD01

Chromosomal expression of the phaCAB operon

38% enhancement in PHB production

10-L fermentor

[135]

TD01 (tat-vgb)

TD01

Periplasmic expression of vgb with the help of the Tat peptide signal

50% improvement in CDW and PHB concentration

Shake flasks

[137]

TDHCD-R3

TDHCD-Ro (TD01 derivative with ΔpyrF deleted, T7-like RNA polymerase Mmp1 and vgb integrated into genome and harbouring mutagenesis plasmid)

Three rounds of selection in medium containing toxic metabolites

41.7% increase in CDW and 8.2% increase in PHB content

7-L fermentor

[24]

TDHCD-R3-8-3

TDHCD-R3

Plasmid expression of phaCAB_Re

12.3% increase in PHB content; CDW of 90.5 g/L with 78.8% (wt) PHB

7-L fermentor

[24]