Production of Reducing Sugar from Coffee Pulp Waste Using Mixture of Microorganisms, Enzymes, and Surfactants

This study has successfully investigated the effect of microorganisms, enzymes, and surfactants mixture to produce a reducing sugar from Coffee pulp waste. The experiment consisted of microbial pretreatment to reduce lignin content followed by comparing the hydrolysis by enzymes and microorganism using a surfactant and without surfactant to get a higher yield of reducing sugar. Pretreatment was conducted by mixture of Bacillus subtilis (BS) with Trichoderma reesei (TR) in the ratio of 2:1 (v/v) and Aspergillus niger (AN) with TR in the ratio of 1:1 (v/v). BS-TR mixture increased the cellulose content to 10.939 % and decreased the lignin and pectin content to 71.261 % and 55.046 %, respectively. Whereas, AN:TR mixture increased the cellulose content to 12.572 % and decreased the lignin and pectin content to 69.941 % and 52.294 %, respectively. Afterward, the result of enzymatic hydrolysis with 3 g of Tween 80 and biological hydrolysis showed increasing of reducing sugar yield of 0.5831 and 0.0341 %, respectively. Further investigation was described as the crystallinity index and the fructose, glucose, and sucrose contents. The addition of both PEG 4000 and Tween 80 as a surfactant in the enzymatic hydrolysis process could significantly increase the concentration of reducing sugar.