Table 1 Consensus clostridial electrotransformation conditions leading to initial low-level transformation of C. pasteurianum

Cell growth

 Growth medium

YTG or 2×YTG

2×YTG

[44, 58, 59]

 Growth phase and OD₆₀₀ at time of harvest

mid to late exponential phase (OD₆₀₀ 0.5–0.9)

OD₆₀₀ 0.6-0.8

[25]

Washing and pulse delivery

 Wash and electroporation buffer

5–7 mM sodium phosphate, pH 6.5-7.4, containing 270 mM sucrose and 1 mM MgCl₂

5 mM sodium phosphate, pH 6.5, containing 270 mM sucrose and 1 mM MgCl₂

[25, 26, 29]

 Number of wash steps

1

1

[44, 45, 58]

 Cuvette gap width

0.4 cm

0.4 cm

[29, 45, 46]

 Volume of cells

600 μl

600 μl

[26]

 Pulse parameters

2.0–2.5 kV; 25 μF; 200–800 Ω; 4–8 ms

2.0–2.5 kV; 25 μF; 200–800 Ω; 6–9 ms

[44, 46]

Outgrowth

 Recovery and plating medium

YTG or 2×YTG

2×YTG

[58, 59]

 Transformation efficiency

Up to 10⁶ transformants μg^-1 DNA

2.4 × 10¹ transformants μg^-1 pMTL85141

[35]