Enzymatic improvement of mitochondrial thiol oxidase Erv1 for oxidized glutathione fermentation by Saccharomyces cerevisiae

Table 2 Growth and volumetric glutathione production of ERV1- and mutant-expressing strains

Expressing gene	Cell growth (g-cell l⁻¹)	GSH (mg l⁻¹)^a	GSSG (mg l⁻¹)^a	Total glutathione (mg l⁻¹)^a
Vector	1.87 ± 0.07 (100)	38.7 ± 4.0 (100)	47.1 ± 1.0 (100)	85.8 ± 4.7 (100)
ERV1	1.77 ± 0.03 (95)	32.3 ± 0.6 (83)	63.4 ± 2.7 (135)**	95.8 ± 3.3 (112)*
ERV1 ^S32A	1.61 ± 0.04 (86)*	20.3 ± 1.1 (52)**	85.2 ± 2.7 (181)**	105.5 ± 5.9 (123)**
ERV1 ^S32T	1.70 ± 0.11 (91)	28.3 ± 2.6 (73)*	70.5 ± 8.4 (150)**	98.8 ± 10.9 (115)
ERV1 ^N34A	1.64 ± 0.14 (88)	26.3 ± 2.8 (68)*	72.3 ± 7.1 (154)**	98.7 ± 9.9 (115)
ERV1 ^S32A/N34A	1.83 ± 0.13 (98)	35.5 ± 3.8 (92)	60.6 ± 1.3 (129)**	96.2 ± 4.5 (112)*
ERV1 ^S32T/N34A	1.71 ± 0.05 (91)*	29.3 ± 2.6 (76)*	76.4 ± 2.9 (162)**	105.7 ± 5.2 (123)**

Culture times are 48 h. Culture conditions are described in the "Methods" section. All fermentations for glutathione production were separately performed three times. All values are represented as mean ± standard deviation (n = 3). Parentheses represent the relative values (%)
Asterisks indicate statistical significances determined by Student’s t test. * p < 0.05. ** p < 0.01
^aVolumetric GSH, GSSG, and total glutathione (GSH and GSSG) concentrations were calculated from the cell concentrations and each cellular content as shown in Fig. 4a–c

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