Optimization of Enzyme Dosage and Sulfuric Acid (H_2SO_4) Concentration on Newspaper Waste Hydrolysis and Fermentation of its Hydrolyzate in Single and Consortium

摘要

Research of the optimum concentration of sulfuric acid (H_2SO_4) on acid hydrolysis and enzyme at the optimum dosage of enzyme hydrolysis of newspaper waste in producing hydrolyzate at optimum levels in reducing sugars and fermentation of its hydrolyzate was conducted. The purpose of this study was to obtain the optimum enzyme dosage and concentration of sulfuric acid hydrolysis of waste paper to produce the best reducing sugar hydrolyzate and microbes to obtain the most effective use of microbial fermentation process. Descriptive and experimental method were used in this research. Descriptive method was applied for evaluating enzyme and acid hydrolysis, preparation hydrolyzate and starter of culture as well as fermentation. The fermentation was conducted by experimental methods using Completely Randomized Design (CRD) with three replications. This study parameter included reducing sugar content, ethanol content, microbial population, Dextrose Equivalent (DE) and pH. Our finding showed that the highest reducing sugar content on sulfuric acid hydrolysis (H_2SO_4) was at a concentration of 6, whereas the liquefaction α-amylase enzyme was at dosage 0.52 μL · g~(-1). The optimum dosage for the hemicellulase enzyme hydrolysis was at 0.001 g · g~(-1), whereas the saccharification cellulase and amyloglucosidase enzyme were 0.83μL · g~(-1) and 0.56μL · g~(-1). The most effective and optimum microbial fermentation process was obtained with a consortium of Zymomonas mobilis and Pichia stipitis that produces the highest ethanol content by 6.523 % at 72 h with fermentation efficiency by 45.77 %. Consortium Zymomonas mobilis and Pichia stipitis also reached the highest end of exponential population phase with 27.5 × 1 010 CFU at 36 h with the highest maximum growth rate by 2.48. Additionally the effectiveness was also supported by the lowest reducing sugar content at 9.09 % with the highest growth yield by 1.689 and the end of Dextrose Equivalent (DE) by 56.140 at the lowest pH of 3.34.