Construction of industrial Saccharomyces cerevisiae strains for the efficient consolidated bioprocessing of raw starch

Table 4 Soluble starch hydrolysing activities (U ml⁻¹) of the industrial S. cerevisiae ER and M2n transformants expressing the temG_Opt glucoamylase and temA α-amylase originating from T. emersonii when grown in 2 × SC^−URA broth for 72 h

	2% raw starch		0.2% soluble starch
	30 °C	37 °C	30 °C	37 °C
Total amylase activity (Reducing sugar assay^a)
ER T1	0.29 (0.10)	0.42 (0.09)	2.03 (0.35)	3.39 (0.20)
ER T12	0.99 (0.02)	1.38 (0.08)	9.11 (0.05)	15.30 (0.52)
M2n T1	0.33 (0.03)	0.48 (0.02)	2.21 (0.05)	3.99 (0.28)
M2n T2	0.20 (0.02)	0.29 (0.03)	1.28 (0.30)	2.46 (0.15)
Released glucose (Glucose kit assay^b)
ER T1	0.15 (0.03)	0.16 (0.04)	1.47 (0.23)	2.12 (0.18)
ER T12	0.44 (0.04)	0.48 (0.06)	4.43 (0.29)	6.32 (0.22)
M2n T1	0.27 (0.01)	0.29 (0.02)	1.11 (0.10)	1.59 (0.12)
M2n T2	0.16 (0.01)	0.17 (0.01)	0.65 (0.15)	0.96 (0.13)

The assays were performed at 30 °C and 37 °C in citrate buffer at pH 5 with raw and soluble corn starch. Parental strains did not give any starch-degrading activities. Values represent the mean of three repeats and standard deviations are reported in parentheses
^aReducing sugar assay detects all reducing sugars (monosaccharides and oligosaccharides)
^bGlucose assay detects only glucose

ISSN: 2731-3654