A novel engineered strain of Methylorubrum extorquens for methylotrophic production of glycolic acid

Table 5 Performance parameters of GA producing M. extorquens TK 0001 strains Mea-GA2 and Mea-GA3 expressing ghrA_eco from E. coli and ecm_mea or ecm_rsh from M. extorquens or R. sphaeroides, respectively

Strain	GX Feed	GP	μ [1 h^-1]	q_MeOH [mmol_MeOH g_CDW⁻¹ h⁻¹]	q_Gox [mmol_Gox g_CDW⁻¹ h⁻¹]	q_C [mmol_C g_CDW⁻¹ h⁻¹]	q_GA [mmol_GA g_CDW⁻¹ h⁻¹]	q_LA [mmol_LA g_CDW⁻¹ h⁻¹]	Y_X/S [g_CDW mol_C⁻¹]	Y_GA/S [mmol_GA mol_C⁻¹]	Y_LA/S [mmol_LA mol_C⁻¹]	Y_GA/X [mmol_GA g_CDW⁻¹]	Y_LA/X [mmol_LA g_CDW⁻¹]
Mea-GA2	−	I	0.13	−14.83	–	−14.83	0.15	0.29	9.08	10.34	19.54	1.14	2.15
		II	0.11	−12.44	–	−12.44	0.31	0.21	8.54	24.78	16.96	2.90	1.99
		III	0.04	−5.36	–	−5.36	0.14	0.15	6.82	26.93	28.10	3.95	4.12
Mea-GA3		I	0.16	−16.38	–	−16.38	0.13	0.23	9.96	7.96	14.11	0.80	1.42
		II	0.07	−10.42	–	−10.42	0.25	0.25	6.48	24.26	23.81	3.74	3.67
		III	0.04	−3.88	–	−3.88	−0.04	0.11	9.30	–	29.54	–	3.18
		III	–	–	–	–	–	−0.08	–	–	–	–	–
Mea-GA2	+	I	0.14	−16.82	−3.08	−22.99	0.29	0.25	5.97	12.64	10.77	2.12	1.80
		II	0.06	−4.54	−2.16	−8.86	0.31	0.09	6.91	34.63	10.41	5.01	1.51
		III	0.03	−6.14	−0.46	−7.05	0.39	0.16	4.64	55.26	22.85	11.91	4.93
Mea-GA3		I	0.16	−9.68	−1.54	−12.76	0.29	0.23	12.39	22.87	18.08	1.85	1.46
		II	0.08	−11.09	−1.95	−14.99	0.84	0.22	5.50	55.73	14.44	10.14	2.63
		III	0.03	−6.33	−0.30	−6.93	0.26	0.24	3.69	37.17	35.26	10.07	9.55

Strains were cultivated under standard conditions without (−) and with ( +) additional supply of 1.5 g L⁻¹ glyoxylate (GX Feed). Specific substrate uptake rates are given for the substrates methanol (q_MeOH) and glyoxylate (q_Gox) individually and as cumulated carbon uptake rate (q_C). Specific product formation rates are given for GA (q_GA) and for the main by-product LA (q_LA). Biomass- and product-substrate yields (Y_X/S, Y_GA/S, Y_LA/S) refer to the consumed molar carbon amount. Product-biomass yields are given for GA (Y_GA/X) and LA (Y_LA/S) individually. All performance parameters were determined individually for the three observed growth phases (GP I-III). Data reflect means of independent biological duplicates

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