Effect of storage conditions on the stability and fermentability of enzymatic lignocellulosic hydrolysate

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Effect of storage conditions on the stability and fermentability of enzymatic lignocellulosic hydrolysate

Publication Type:

Journal Article

Source:

Bioresource Technology, Volume 147, p.212-220 (2013)

Keywords:

Conversion, Deconstruction, Enabling Technologies

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 AFEXTM (Ammonia Fiber Expansion) 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.