Enhanced enzymatic hydrolysis of eucalyptus by synergy of zinc chloride hydrate pretreatment and bovine serum albumin

- A simple and effective ZnCl2 hydrate pretreatment was developed in this study.
- ZnCl2 hydrate pretreatment generated highly digestible pretreated solid.
- BSA additive showed great potential for reducing cellulase dosage.
- High yield sugar was obtained after pretreatment and enzymatic hydrolysis.

Enhancement of eucalyptus enzymatic saccharification by synergy of ZnCl2 hydrate pretreatment and bovine serum albumin (BSA) was investigated in this study. The result showed that the ZnCl2 hydrate pretreatment could not only selectively extract up to ∼100% of the hemicellulose from eucalyptus, but also convert portion of high crystalline cellulose I into low crystalline cellulose II, which both beneficial for enhancing subsequent pretreated solids enzymatic saccharification. The addition of BSA into enzymatic hydrolysis step could significantly promote the glucose release from pretreated solids, especially, under the low enzyme loading. Furthermore, the material balance indicated that the highest glucose yield of this study was 35.5 g/100 g raw material, which representing 90.3% of glucose in raw eucalyptus, combined with the xylose yield, 13.9 g/100 g eucalyptus, it can be concluded that ZnCl2 hydrate pretreatment offered the potential to co-produce xylose and glucose from eucalyptus.

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