Table 4.

Relative growth rates on single amino acids as carbon sources

Amino acidRelative growth rate (±SD,n = 2)a
G0 (ZK2557)GI (ZK2553)GIsgaA(ZK2561)GIsgaB(ZK2559)GIsgaC(ZK2563)GII (ZK2555)
Alanine1.00 (±0.01)1.04 (±0.02)0.88 (±0.00)1.25 (±0.01)1.11 (±0.02)1.21 (±0.01)
Asparagine01.00 (±0.03)1.90 (±0.04)0.69 (±0.03)0.72 (±0.04)1.60 (±0.03)
Aspartate001.00 (±0.01)000.53 (±0.00)
Glutamate1.00 (±0.03)2.93 (±0.01)9.14 (±0.00)1.92 (±0.07)2.17 (±0.03)9.29 (±0.00)
Glutamineb 01.00 (±0.02)0.87 (±0.04)0.75 (±0.09)0.76 (±0.03)0.82 (±0.00)
Serine1.00 (±0.05)1.63 (±0.36)0.86 (±0.06)9.81 (±0.66)2.30 (±0.14)9.19 (±0.28)
Threonine1.00 (±0.02)2.17 (±0.11)1.16 (±0.02)3.66 (±0.00)3.92 (±0.11)5.01 (±0.04)
Prolinec 1.00 (±0.1)0.72 (±0.11)2.1 (±0.1)0.45 (±0.05)1.6 (±0.1)10.5 (±0.7)
  • a For all amino acids except proline (see footnote c), growth rates in liquid M63 plus 0.5% amino acid (plus 0.03% isoleucine) medium were determined. A relative growth rate of 1.00 indicates a generation time (in hours) of 4.50 on alanine, 14.0 on asparagine, 11.2 on aspartate, 58.5 on glutamate, 12.0 on glutamine, 61.2 on serine, or 304 on threonine; a relative growth rate of zero indicates no growth.

  • b Cultures stopped growing at an OD of 600 nm of 0.2 to 0.3. This was not due to alkalinization of the medium, as the pH remained below 7.5, nor was it due to end product inhibition, as the cultures grew readily when spiked with 0.2% glucose.

  • c Overnight LB cultures were diluted into M63 medium and plated on M63 proline (0.5%) plus isoleucine (0.03%). Values indicate relative colony areas (±SD, n = 20) after 4 days of incubation.