From wheat straw to bioethanol: integrative analysis of a separate hydrolysis and co-fermentation process with implemented enzyme production

Table 2 Mass balance analysis of the benchtop SHCF process

	Input	Output
1st step: enzyme production ( *T. reesei* SVG17)
Pre-cultures (WS_pre-culture)	5.6 g DM WS
Batch cultivation (WS_{fungal ferm})	120 g DM WS
Total cellulolytic activity		1.7 FPU/mL
ηHandling 75%		5,100 FPU total
2nd step: saccharification (enzymatic hydrolysis)
Substrate loading (WS_{enz hydrolysis})	170 g DM WS
Glucose (ηGlucose 67%, ηHandling 75%)		39.5 g
Xylose (ηXylose 95%, ηHandling 75%)		18.4 g
3rd step: ethanol production ( *S. cerevisiae* IBB10B05)
Ethanol (Y _Ethanol 0.4 g/g_Glc+Xyl)		23.1 g
Total
Substrate loading - pre-treated	295.6 g DM WS
Substrate loading - raw material	325.2 g DM RM
Ethanol		23.1 g
Y _{Ethanol-Process}	71.2 g_Ethanol/kg_{DM RM}

An overview of the process is depicted in Figure 1. Boundary conditions: batch fermentations with 30 g_{DM WS}/L, 15% DM WS, and 30 FPU/g_{DM WS.}

ISSN: 1754-6834