Cassava pulp enzymatic hydrolysis process as a preliminary step in bio-alcohols production from waste starchy resources
Cassava pulp enzymatic hydrolysis process as a preliminary step in bio-alcohols production from waste starchy resources
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木薯浆酶解工艺作为废淀粉资源生产生物醇的第一步
DOI：
10.1016/j.jclepro.2012.07.055
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发表时间：
2013
影响因子：
11.1
通讯作者：
W. Chulalaksananukul
中科院分区：
文献类型：
--
作者：
Chompunuch Virunanon;Chanika Ouephanit;Vorakan Burapatana;W. Chulalaksananukul
木薯淀粉工厂产生大量的废水和固体废物，需要几个步骤的废物处理来管理。特别是固体废物含有高水平的淀粉-木质纤维素生物质，特别是木薯浆（CP）。上述废水也含有残留的木薯成分，通常被称为木薯废水（CWW）。这些剩余资源是生产生物燃料（可再生能源载体）的潜在有前途的底物，例如丙酮-丁醇-乙醇（ABE）发酵过程产生的产品。淀粉-木质纤维素底物在发酵前采用酸水解与酶水解的传统组合步骤，存在酸污染废弃物、水解反应过程耗时长（数小时）等复杂问题。为了解决这些问题，以木薯浆（CP）单独或添加木薯淀粉废水（CWW）作为模型原料（原料），并建立了适应的一步酶解方法。这一步酶解过程缩短了最佳处理时间（2小时），并且产生的还原糖水平等于先前报道的酸水解和酶水解两阶段结合的水平。在对淀粉进行一步酶解后，将还原糖溶液分别用酿酒酵母（Saccharomyces cerivisae） TISTR5339或丁酸梭菌（Clostridium butyricum TISTR1032）发酵，生产乙醇和ABE。在无菌废水中（利用酿酒酵母）对CP （67 g/L）进行乙醇发酵，产生的生物产物混合物的乙醇含量（除其他成分外）为8.8 g/L，但用CWW代替水后，乙醇浓度增加到12.9 g/L。与C. butyricum单独发酵糖化CP或与CWW一起发酵，ABE的总产量分别为9.65 g/L和10.24 g/L，但添加CWW后，乙醇产量从9 g/L（占溶剂组成的93%）降至1.64 g/L（占溶剂组成的16%），其中丁醇为主要产物（53.2%;2.5 g/L）。
Tapioca starch factories generate a large amount of wastewater and solid waste which take several steps of waste treatment to manage. The solid waste in particular contains a high level of starchy-lignocellulosic biomass, especially cassava pulp (CP). The wastewater, above mentioned, contains also residual cassava constituents and, usually are named cassava wastewater (CWW). These residual resources are potentially promising substrates for the production of biofuels (renewable energy carriers), such as products resulted from acetone-butanol-ethanol (ABE) fermentation process. The conventional combination steps between acid hydrolysis and enzymatic hydrolysis of starchy-lignocellulosic substrate, before fermentation process, generate complicated problems such as acid contaminated waste and spending of a long time (several hours) for hydrolysis reaction process. To address these problems, cassava pulp (CP) alone or supplemented with cassava starch wastewater (CWW) was used as a model feedstock (raw material) and an adapted one step enzymatic hydrolysis was created. This one step enzymatic hydrolysis process shows a shortened optimum treatment time (2 h) and yielded a reducing sugar level that was equal to that previously reported for the two stage combination between of acid hydrolysis and enzymatic hydrolysis. After adapted one step enzymatic hydrolysis of the starch the reducing sugar solution was fermented using either Saccharomyces cerivisiae TISTR5339 or Clostridium butyricum TISTR1032 for ethanol and ABE production, respectively. The ethanolic fermentation (by using S. cerevisiae) of CP (67 g/L) in sterilized wastewater solution, yielded a bioproduct mixture having a content consisting (beside other components) from 8.8 g/L of ethanol, but this ethanol concentration was increased to 12.9 g/L with the replacement of the water by CWW. Fermentation of the saccharified CP alone or with CWW with C. butyricum yielded a total ABE production of 9.65 g/L and 10.24 g/L, respectively, but the ethanolic production was reduced from 9 g/L (93% of the solvent composition) to 1.64 g/L (16% solvent composition) by the addition of the CWW, with butanol as the major product (53.2%; 2.5 g/L).