微生物预处理对苹果渣原料糖化及燃料乙醇发酵效果的影响

Effect of microbial pre-treatment on the saccharification and cellulic ethanol production of apple pomace

【目的】研究微生物预处理途径制备苹果渣乙醇的特性,为纤维乙醇生产开拓新的廉价原料和低耗工艺提供技术支撑。【方法】以不同用量白腐菌（Trametes versicolor）或褐腐菌（Gloeophyllum trabeum）单菌预处理及其与黑曲霉（Aspergillus niger）复合的双菌预处理、半固态或液态配料对苹果渣进行不同的预处理,再分别采用2种黑曲霉菌株糖化,2种酵母和2种工艺发酵,测定不同步骤醪液的糖化产糖含量、总糖含量、乙醇生成量等。【结果】半固态条件下,0.8 mL白腐菌菌悬液单菌预处理的促进糖化效果最强,原料总糖含量提高70.8%。液态条件下,黑曲霉与白腐菌复合预处理促进苹果渣糖化能力最强,总糖含量提高66.2%;黑曲霉原始菌株与UA8菌株对半固态预处理后苹果渣未表现促进糖化的作用,对液态预处理苹果渣糖化作用明显,且以UA8菌株作用较强,糖化产糖量达到14.2~15.5 g/kg。黑曲霉与白腐菌组合的乙醇生成量均高于其他预处理组,且以液态配料方式高于半固态方式。啤酒酵母发酵醪的乙醇产量较安琪酵母有所提高;一步法发酵酒精生成高峰较二步法提前,发酵周期短。【结论】在各步骤选定的菌种和用量条件下,苹果渣经微生物预处理、一步法发酵的技术路线是一条高产纤维乙醇工艺,发酵8d内乙醇生成量达到228.4 mL/kg（干渣）。

【Objective】 The research investigated the characteristics of ethanol preparation from pomace under the pre-treatment with microganism in order to choose cheaper material and low-cost technology for cellulic ethanol.【Method】 Apple pomace was pre-treated with single fungun of Trametes versicolor or Gloeophyllum trabeum,or compound fungi as each was mixed with Aspergillus niger under hemi-solid or liquid state,then sachrified with either of A.niger strains,fermented with two species of yeast and two procedures,respectively.Saccharification sugar,soluble sugar and ethanl yield were determined.【Result】 Under hemi-solid state,single microbial treatment with 0.8 mL T.versicolor suspendance showed the best effect on sacchrification,which increased the total sugar content by 70.8%.Under liquid state,compound pre-treatment with T.versicolor and A.niger showed the best effect on sacchrification,which increased the total sugar content by 66.2%.Native strain and UA8 strain of A.niger played no role in the sacchrification of hemi-solid pre-treated pomace,whereas,their apparent roles were found in liquid pre-treated pomace and UA8 presented stronger effect with a saccharification yield of 14.2-15.5 g/kg.Compound pre-treatment of T.versicolor and A.niger resulted in higher ethanol yield than other treatments and the effect was better under liquid state than under hemi-solid state.Ethanol yield by Saccharomyces cerevisiae Hansen was higher than that by Anqi yeast in each treatment.Peak ethanol appeared earlier in simultaneous sacchrification and fermentation than that in two step process of sacchrification and fermentation,resulting in a shorter fermentation cycle.【Conclusion】 Under the selected fungi species and dosage for each step,a high cellulic ethanol technology with apple pomace was derived as microbial pre-treatment,then simultaneous sacchrification and fermentation,maximum ethanol yield of which was 228.4 mL/kg in 8 days.