澱粉混在セルロース系バイオマス・キャッサバパルプからのバイオ燃料及びバイオマテリアル生産技術開発

この博士論文は内容の要約のみの公開（または一部非公開）になっています筑波大学 (University of Tsukuba)201

Production of Ligninolytic Enzymes by White-Rot Fungus Datronia

This study focused on decolorization of 2 reactive dyes; Reactive Blue 19 (RBBR) and Reactive Black 5 (RB5), by selected white-rot fungus Datronia sp. KAPI0039. The effects of reactive dye concentration, fungal inoculum size as well as pH were studied. Samples were periodically collected for the measurement of color unit, Laccase (Lac), Manganese Peroxidase (MnP), and Lignin Peroxidase (LiP) activity. Eighty-six percent of 1,000 mg L−1 RBBR decolorization was achieved by 2% (w/v) Datronia sp. KAPI0039 at pH 5. The highest Lac activity (759.81 UL−1) was detected in the optimal condition. For RB5, Datronia sp. KAPI0039 efficiently performed (88.01% decolorization) at 2% (w/v) fungal inoculum size for the reduction of 600 mg L−1 RB5 under pH 5. The highest Lac activity (178.57 UL−1) was detected, whereas the activity of MnP and LiP was absent during this hour. The result, therefore, indicated that Datronia sp. KAPI0039 was obviously able to breakdown both reactive dyes, and Lac was considered as a major lignin-degradation enzyme in this reaction

Consolidated bioprocessing of starchy substrates into ethanol by industrial Saccharomyces cerevisiae strains secreting fungal amylases

The development of a yeast strain that converts raw starch to ethanol in one step (called Consolidated Bioprocessing, CBP) could significantly reduce the commercial costs of starch-based bioethanol. An efficient amylolytic Saccharomyces cerevisiae strain suitable for industrial bioethanol production was developed in this study. Codon-optimized variants of the Thermomyces lanuginosus glucoamylase (TLG1) and Saccharomycopsis fibuligera -amylase (SFA1) genes were -integrated into two S. cerevisiae yeast with promising industrial traits, i.e., strains M2n and MEL2. The recombinant M2n[TLG1-SFA1] and MEL2[TLG1-SFA1] yeast displayed high enzyme activities on soluble and raw starch (up to 8118 and 4461nkat/g dry cell weight, respectively) and produced about 64g/L ethanol from 200g/L raw corn starch in a bioreactor, corresponding to 55% of the theoretical maximum ethanol yield (g of ethanol/g of available glucose equivalent). Their starch-to-ethanol conversion efficiencies were even higher on natural sorghum and triticale substrates (62 and 73% of the theoretical yield, respectively). This is the first report of direct ethanol production from natural starchy substrates (without any pre-treatment or commercial enzyme addition) using industrial yeast strains co-secreting both a glucoamylase and -amylase

Statistical Approach for Optimization of Ethanol Production from Fast-growing Trees: Acacia mangium and Acacia hybrid

This is the first report of the potential of Acacia fast growing trees in Thailand, A. mangium and the Acacia hybrid (A. mangium x A. auriculiformis), as raw material for ethanol production through a simultaneous saccharification and fermentation process by Saccharomyces cerevisiae TISTR 5339. Alkaline pulping was applied as the pretreatment process. Optimization of ethanol production was studied using response surface methodology based on central composite design. The optimized conditions of 100 g/L solid loading and an A600 of S. cerevisiae TISTR 5339 of 2 gave observed values of ethanol production of 35.7 and 27.3 g/L, which corresponded with the predicted values of 32.32 and 26.37g/L from A. mangium and A. hybrid, respectively. This condition was then used for up-scaling in a 10-L stirred bioreactor. The improved maximum ethanol concentrations of 37.84 and 36.52 g/L were obtained from A. mangium and Acacia hybrid, respectively, within 96 h of cultivation at 30 °C and no aeration rate