TABLE 1.
Growth of M. barkeri mutant strains on various methanogenic substrates
| Genotype | H2-CO2 |
Methanol |
Methanol-H2-CO2 |
Acetate |
||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Gen. (h)d | Max. ODe | Lag (h) | Gen. (h) | Max. ODe | Lag (h) | Gen. (h) | Max. ODe | Lag (h) | Gen. (h) | Max. ODf | Lag (h) | |
| Δhpta | 10.4 ± 0.7 | 0.42 ± 0.04 | 49 ± 11 | 8.9 ± 0.3 | 0.85 ± 0.05 | 36 ± 1 | 6.2 ± 0.5 | 0.77 ± 0.03 | 33 ± 1 | 43.6 ± 2.2 | 1.65 ± 0.04 | 195 ± 11 |
| Δfre | 10.3 ± 0.6 | 0.35 ± 0.03 | 59 ± 1 | 8.8 ± 0.4 | 0.78 ± 0.04 | 37 ± 1 | 7.0 ± 0.4 | 0.68 ± 0.01 | 38 ± 4 | 38.6 ± 2.3 | 1.68 ± 0.05 | 200 ± 13 |
| Δvhx | 10.7 ± 0.5 | 0.45 ± 0.02 | 60 ± 3 | 8.5 ± 0.2 | 0.78 ± 0.08 | 36 ± 2 | 7.5 ± 0.5 | 0.69 ± 0.04 | 51 ± 3 | 47.2 ± 3.8 | 1.70 ± 0.08 | 181 ± 22 |
| Δech | NGg | NAh | NA | 12.2 ± 0.9 | 0.69 ± 0.05 | 46 ± 1 | NG | NA | NA | NG | NA | NA |
| Δech Δfrh | NG | NA | NA | 12.1 ± 0.7 | 0.80 ± 0.05 | 54 ± 2 | 13 ± 2 | 0.54 ± 0.03 | 248 ± 17 | NG | NA | NA |
| Δech Δfrh Δvht | NG | NA | NA | 10.8 ± 0.2 | 0.71 ± 0.06 | 48 ± 3 | 9.0 ± 0.4 | 0.61 ± 0.02 | 48 ± 2 | NG | NA | NA |
| Δech Δfrh Δfre Δvht-vhxc | NG | NA | NA | 12.1 ± 0.2 | 0.84 ± 0.06 | 54 ± 2 | 9.3 ± 0.1 | 0.68 ± 0.03 | 45 ± 1 | NG | NA | NA |
| Ptet vhtb | NG | NA | NA | NG | NA | NA | NG | NA | NA | NG | NA | NA |
| Ptet vht Δechb | NG | NA | NA | NG | NA | NA | NG | NA | NA | NG | NA | NA |
| Δfrh Δvht | NG | NA | NA | 11.7 ± 0.7 | 0.89 ± 0.01 | 54 ± 2 | 35 ± 3 | 0.33 ± 0.03 | 151 ± 4 | NG | NA | NA |
| Δfrh Δfre Δvht-vhxc | NG | NA | NA | 12.3 ± 0.6 | 0.84 ± 0.07 | 58 ± 2 | 29 ± 2 | 0.43 ± 0.03 | 116 ± 3 | NG | NA | NA |
| Δfrh | NG | NA | NA | 19.5 ± 1.0 | 0.69 ± 0.05 | 122 ± 6 | 7.4 ± 0.6 | 0.64 ± 0.14 | 45 ± 3 | 38.2 ± 1.7 | 1.71 ± 0.03 | 219 ± 11 |
| Δfrh Δfre | NG | NA | NA | 16.5 ± 0.8 | 0.80 ± 0.00 | 89 ± 2 | 7.7 ± 0.2 | 0.74 ± 0.01 | 48 ± 1 | 39.6 ± 2.9 | 1.63 ± 0.07 | 170 ± 13 |
a
The M. barkeri Fusaro parental strain.
b
Growth in the absence of tetracycline.
c
Mbar_A1842 and Mbar_1843 were also deleted.
d
Gen., generation (doubling) time.
e
The maximum (max.) optical density at 600 nm was measured on a Spectronic 20 spectrophotometer.
f
The maximum (max.) optical density at 600 nm was measured on a Hewlett Packard 8453 spectrophotometer. Note that an OD of 1.0 on the Hewlett Packard 8453 spectrophotometer is equivalent to an OD of ∼0.2 on the Spectronic 20 spectrophotometer.
g
NG, no growth for at least 6 months of incubation.
h
NA, not applicable.