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Table 3 Comparison of simultaneous saccharification and fermentation methods using SO2 pretreatment of softwoods with Saccharomyces cerevisiae strains

From: A strain of Saccharomyces cerevisiaeevolved for fermentation of lignocellulosic biomass displays improved growth and fermentative ability in high solids concentrations and in the presence of inhibitory compounds

Yeast straina Wood type Pretreatmentb Solids, % dry weight/volume Inoc, g/L Cellulase, FPU/gram dry weight Max EtOH, g/L Time to maximum EtOH production, hours % TM Reference
   SO2 conc. Reaction temp, °C Duration, min        
Tembec 1 Lodgepole pine 4.0 200 5 5% (washed) 5 40 FPU/g cellulase, 20 CU/g cellobiase 17.0 24 68c Ewanick et al. [36] (note: 6 hours enzyme preincubation)
Tembec 1 Douglas fir 4.5 195 4.5d 40 mL, WSF 5 No enzymes added 13.8 24 87e Keating et al. [37]
Y-1528 Douglas fir        14.7 24 92f  
Baker's yeast Spruce 2.5 215 5 8% 5 32 FPU/g cellulase, 28 IU/g cellobiase Not stated 72 60f Alkasrawi et al. [25]
Baker's yeastg          72 92f  
TMB 3000          48 89f  
Baker's yeast Spruce 3.0 215 5 5% 5 15 FPU/g cellulose, 23 CU/g cellobiase Not stated 24 49f Söderström et al. [35]
Baker's yeast Spruce 3.0 210 5 12% WIS 5 15 FPU/g cellulose, 23 CU/g cellobiase 20.0 (graph) 72 37f Hoyer et al. [38]
XR122N Pine 3.3 215 5 10% 4 15 FPU/g cellulose, 60 CU cellobiase 28.7 48 98c This study
XR122N Pine 3.3 215 5 12% 4 15 FPU/g cellulose, 60 CU cellobiase 23.6 48 76c This study
  1. Abbreviations: FPU, filter paper unit; Inoc, inoculation; CU, cellobiase unit; temp, temperature; WIS, water-insoluble solids; WSF, water-soluble fraction.
  2. aSaccharomyces.
  3. bAll biomass was pretreated with SO2 in a single step and was not delignified before pretreatment or fermentation.
  4. cTheoretical yield based on cellulose and hemicellulose content derived from gravimetric and analytical analyses of pretreated material.
  5. dSteam explosion output was diluted to 15% w/w and filtered, and the pH altered to 6.0. Suspended solids not filtered out.
  6. eTheoretical yield was based on the content of glucose and mannose in the pretreated material.
  7. fTheoretical yield was based on the content of glucose and mannose in the liquid and of glucan in the solid material.
  8. gIn hydrolysate.