Anaerobic thermophilic fermentation for carboxylic acid production from in-storage air-lime-treated sugarcane bagasse

作者：Fu Zhihong^*; Holtzapple Mark T

来源：Applied Microbiology and Biotechnology, 2011, 90(5): 1669-1679.

DOI：10.1007/s00253-011-3178-6

• Mixed-culture fermentation
• Air-lime pretreatment
• Carboxylate platform
• Ultimate consolidated bioprocessing
• Simultaneous storage and pretreatment
• Marine microorganisms

Wet storage and in situ lime pretreatment (50 A degrees C, 1-atm air, 56 days, excess lime loading of 0.3 g Ca(OH)(2)/g dry biomass) of sugarcane bagasse (4,000 g dry weight) was performed in a bench-scale pile pretreatment system. Under thermophilic conditions (55 A degrees C, NH(4)HCO(3) buffer, methane inhibitors), air-lime-treated bagasse (80 wt.%) and chicken manure (20 wt.%) were anaerobically co-digested in 1-L rotary fermentors by a mixed culture of marine microorganisms (Galveston, TX). During four-stage countercurrent fermentation, the resulting carboxylic acids consisted of primarily acetate (average 87.7 wt.%) and butyrate (average 9.0 wt.%). The experimental fermentation trains had the highest yield (0.47 g total acids/g volatile solids (VS) fed) and highest selectivity (0.79 g total acids/g VS digested) at a total acid concentration of 28.3 g/L, which is equivalent to an ethanol yield of 105.2 gal/(tonne VS fed). Both high total acid concentrations (> 44.7 g/L) and high substrate conversions (> 77.5%) are predicted for countercurrent fermentations of bagasse at commercial scale, allowing for an efficient conversion of air-lime-treated biomass to liquid transportation fuels and chemicals via the carboxylate platform.

• 出版日期2011-6