Author/Authors :
Jin، نويسنده , , Mingjie and Bothfeld، نويسنده , , William and Austin، نويسنده , , Samantha and Sato، نويسنده , , Trey K. and La Reau، نويسنده , , Alex X. Li، نويسنده , , Haibo and Foston، نويسنده , , Marcus and Gunawan، نويسنده , , Christa and LeDuc، نويسنده , , Richard D. and Quensen، نويسنده , , John F. and Mcgee، نويسنده , , Mick and Uppugundla، نويسنده , , Nirmal and Higbee، نويسنده , , Alan and Ranatu، نويسنده ,
Abstract :
To minimize the change of lignocellulosic hydrolysate composition during storage, the effects of storage conditions (temperature, pH and time) on the composition and fermentability of hydrolysate prepared from AFEX™ (Ammonia Fiber Expansion – a trademark of MBI, Lansing, MI) pretreated corn stover were investigated. Precipitates formed during hydrolysate storage increased with increasing storage pH and time. The precipitate amount was the least when hydrolysate was stored at 4 °C and pH 4.8, accounting for only 0.02% of the total hydrolysate weight after 3-month storage. No significant changes of NMR (Nuclear Magnetic Resonance) spectra and concentrations of sugars, minerals and heavy metals were observed after storage under this condition. When pH was adjusted higher before fermentation, precipitates also formed, consisting of mostly struvite (MgNH4PO4·6H2O) and brushite (CaHPO4·2H2O). Escherichia coli and Saccharomyces cerevisiae fermentation studies and yeast cell growth assays showed no significant difference in fermentability between fresh hydrolysate and stored hydrolysate.
Keywords :
AFEX , Hydrolysate fermentation , Hydrolysate precipitate , Hydrolysate storage , Hydrolysate characterization
