Faculty of Chemical Engineering, Technion-Israel Institute of Technology, 32000, Haifa, Israel.
Bioprocess Biosyst Eng. 2017 Nov;40(11):1635-1641. doi: 10.1007/s00449-017-1819-6. Epub 2017 Jul 25.
Cellulose is one of the most abundant bio-renewable materials on earth, yet the potential of cellulosic bio-fuels is not fully exploited, primarily due to the high costs of conversion. Hydrogel particles of regenerated cellulose constitute a useful substrate for enzymatic hydrolysis, due to their porous and amorphous structure. This article describes the influence of several structural aspects of the cellulose hydrogel on its hydrolysis. The hydrogel density was shown to be directly proportional to the cellulose concentration in the initial solution, thus affecting its hydrolysis rate. Using high-resolution scanning electron microscopy, we show that the hydrogel particles in aqueous suspension exhibit a dense external surface layer and a more porous internal network. Elimination of the external surface layer accelerated the hydrolysis rate by up to sixfold and rendered the process nearly independent of cellulose concentration. These findings may be of practical relevance to saccharification processing costs, by reducing required solvent quantities and enzyme load.
纤维素是地球上最丰富的可再生生物材料之一，但由于转化成本高，纤维素生物燃料的潜力尚未得到充分开发。再生纤维素水凝胶颗粒由于其多孔和无定形结构，构成了用于酶水解的有用基质。本文描述了纤维素水凝胶的几个结构方面对其水解的影响。水凝胶的密度与初始溶液中纤维素的浓度成正比，从而影响其水解速率。使用高分辨率扫描电子显微镜，我们表明水凝胶颗粒在水悬浮液中表现出致密的外部表面层和更多孔的内部网络。消除外部表面层可将水解速率提高多达六倍，并使该过程几乎与纤维素浓度无关。这些发现对于降低糖化处理成本（减少所需溶剂的量和酶的负载）可能具有实际意义。
