TABLE 4.
Effect of chromosomal integration of different IRC7 alleles in the haploid strain AWRI1631 in sulfur compound formation during fermentation of 90 ml of SGJ-thiol medium
| AWRI1631 construct | Sulfur compounda
|
|||
|---|---|---|---|---|
| H2S tube (µg) | 4-MMP (ng·liter−1) | 3-MH (ng·liter−1) | 3-MHA (ng·liter−1) | |
| No yeast | ND | 107 | ND | ND |
| IRC7S | 122 BC | 662 G | 324 F | 9.6 E |
| IRC7L | 178 A | 14,672 A | 961 A | 61.4 A |
| IRC7L T185A | 135 B | 5,469 B | 564 C | 28.2 C |
| IRC7L T185A K43R | 121 BC | 4,549 D | 563 C | 25.1 CD |
| IRC7L T185A P146R | 121 BC | 3,559 E | 531 CD | 20.6 DE |
| IRC7L T185A G253R | 94 C | 652 G | 367 EF | 7.6 F |
| IRC7L T185A G321D | 116 BC | 2,303 F | 453 DE | 16.5 E |
| IRC7L T185A E323G | 123 BC | 4,849 C | 740 B | 40.8 B |
a
Each results is expressed as the mean of three independent replicates; standard deviations were typically 10% and never exceeded 20%. The conversion yields of the AWRI1631 IRC7L strain for Cys-3-MH and Cys-4-MMP were 0.78% and 12.1%, respectively. H2S released during fermentation (H2S tube) was measured with silver nitrate selective gas detector tubes. Means with the same letter are not significantly different from each other (Tukey’s HSD test, P < 0.05). ND, not detected.