Increased isobutanol production in Saccharomyces cerevisiae by overexpression of genes in valine metabolism

Table 2 Aerobic batch cultivations of the ILV2 ILV3 ILV 5 overexpression strain and reference strain in shake flasks^a

	Buffered mineral medium		YPD complex medium
	Reference stain^b	ILV2 ILV3 ILV5 overexpression strain ^b	Reference strain	ILV2 ILV3 ILV5 overexpression strain
Specific growth rate, per h	0.36 ± 0.00	0.11 ± 0.00	0.52 ± 0.00	0.50 ± 0.00
Biomass (CH_1.78O_0.6N_0.19) yield, g/g glucose	0.33 ± 0.06	0.14 ± 0.05	0.34 ± 0.00	0.35 ± 0.00
Ethanol yield, g/g glucose	0.22 ± 0.05	0.28 ± 0.10	0.12 ± 0.01	0.19 ± 0.02
Pyruvate yield, g/g glucose	0.0002 ± 0.0000	0.0002 ± 0.0000	0.0137 ± 0.0003	0.0134 ± 0.0005
Succinate yield, g/g glucose	0.20 ± 0.02	0.26 ± 0.01	0.02 ± 0.00	0.01 ± 0.00
Glycerol yield, g/g glucose	0.006 ± 0.006	0.026 ± 0.017	0.002 ± 0.000	0.013 ± 0.000
Acetate yield, g/g glucose	0.0000 ± 0.0000	0.0052 ± 0.0022	0.0929 ± 0.0047	0.0929 ± 0.0018

^aThe cultivations were carried out in shake flask. Buffered mineral medium containing 40 g/l glucose and YPD complex medium containing 17 g/l glucose were used.
^bThe reference strain used was CEN.PK 113-5D. The overexpression strain used was ILV235_XCY561.
YPD = yeast extract/peptone/dextrose.

ISSN: 2731-3654