Department of Agronomy Food Natural resources Animals and Environment (DAFNAE), Università di Padova, Agripolis, Viale dell'Università 16, 35020 Legnaro, PD, Italy.
Department of Agronomy Food Natural resources Animals and Environment (DAFNAE), Università di Padova, Agripolis, Viale dell'Università 16, 35020 Legnaro, PD, Italy.
Bioresour Technol. 2017 Nov;244(Pt 1):151-159. doi: 10.1016/j.biortech.2017.07.108. Epub 2017 Jul 24.
This work describes the feasibility of using rice milling by-products as feedstock for bioethanol. Starch-rich residues (rice bran, broken, unripe and discolored rice) were individually fermented (20%w/v) through Consolidated Bioprocessing by two industrial engineered yeast secreting fungal amylases. Rice husk (20%w/v), mainly composed by lignocellulose, was pre-treated at 55°C with alkaline peroxide, saccharified through optimized dosages of commercial enzymes (Cellic® CTec2) and fermented by the recombinant strains. Finally, a blend of all the rice by-products, formulated as a mixture (20%w/v) according to their proportions at milling plants, were co-processed to ethanol by optimized pre-treatment, saccharification and fermentation by amylolytic strains. Fermenting efficiency for each by-product was high (above 88% of the theoretical) and further confirmed on the blend of residues (nearly 52g/L ethanol). These results demonstrated for the first time that the co-conversion of multiple waste streams is a promising option for second generation ethanol production.
本研究探讨了以稻米加工副产物为原料生产生物乙醇的可行性。富含淀粉的残渣（米糠、碎米、未成熟米和变色米）分别以 20%（w/v）的浓度经两种工业工程酵母发酵（Consolidated Bioprocessing），这两种酵母能分泌真菌淀粉酶。主要由木质纤维素组成的稻壳（20%（w/v））在 55°C 下用碱性过氧化物预处理，通过优化商业酶（Cellic® CTec2）的用量进行糖化，并由重组菌株发酵。最后，根据稻米加工厂的比例将所有稻米副产物混合（20%（w/v）），通过优化的预处理、糖化和淀粉酶菌株发酵进行共加工生产乙醇。每种副产物的发酵效率都很高（高于理论值的 88%），在残渣混合物上进一步得到验证（接近 52g/L 乙醇）。这些结果首次表明，多废物流的共转化是第二代乙醇生产的一种很有前途的选择。
