1.0. Introduction 4044 2.0. Biomass Chemistry and Growth Rates 4047 2.1. Lignocellulose and Starch-Based Plants 4047 2.2. Triglyceride-Producing Plants 4049 2.3. Algae 4050 2.4. Terpenes and Rubber-Producing Plants 4052 3.0. Biomass Gasification 4052 3.1. Gasification Chemistry 4052 3.2. Gasification Reactors 4054 3.3. Supercritical Gasification 4054 3.4. Solar Gasification 4055 3.5. Gas Conditioning 4055 4.0. Syn-Gas Utilization 4056 4.1. Hydrogen Production by Water−Gas Shift Reaction 4056

/pdf/synthesis-of-transportation-fuels-from-biomass-chemistry-3sckhzoqoz.pdf

Synthesis of transportation fuels from biomass: chemistry, catalysts, and engineering.

https://faculty.washington.edu/renatab/courses/PSE490/downloads/pretreatment.pdf

Features of promising technologies for pretreatment of lignocellulosic biomass.

Fundamental features of microbial cellulose utilization are examined at successively higher levels of aggregation encompassing the structure and composition of cellulosic biomass, taxonomic diversity, cellulase enzyme systems, molecular biology of cellulase enzymes, physiology of cellulolytic microorganisms, ecological aspects of cellulase-degrading communities, and rate-limiting factors in nature. The methodological basis for studying microbial cellulose utilization is considered relative to quantification of cells and enzymes in the presence of solid substrates as well as apparatus and analysis for cellulose-grown continuous cultures. Quantitative description of cellulose hydrolysis is addressed with respect to adsorption of cellulase enzymes, rates of enzymatic hydrolysis, bioenergetics of microbial cellulose utilization, kinetics of microbial cellulose utilization, and contrasting features compared to soluble substrate kinetics. A biological perspective on processing cellulosic biomass is presented, including features of pretreated substrates and alternative process configurations. Organism development is considered for "consolidated bioprocessing" (CBP), in which the production of cellulolytic enzymes, hydrolysis of biomass, and fermentation of resulting sugars to desired products occur in one step. Two organism development strategies for CBP are examined: (i) improve product yield and tolerance in microorganisms able to utilize cellulose, or (ii) express a heterologous system for cellulose hydrolysis and utilization in microorganisms that exhibit high product yield and tolerance. A concluding discussion identifies unresolved issues pertaining to microbial cellulose utilization, suggests approaches by which such issues might be resolved, and contrasts a microbially oriented cellulose hydrolysis paradigm to the more conventional enzymatically oriented paradigm in both fundamental and applied contexts.

/pdf/microbial-cellulose-utilization-fundamentals-and-4yec12qx1c.pdf

Microbial cellulose utilization: fundamentals and biotechnology.

Pretreatments to enhance the digestibility of lignocellulosic biomass

Pretreatment technologies for an efficient bioethanol production process based on enzymatic hydrolysis: A review

Les biocatalyseurs peuvent etre recuperes a partir de la phase dans laquelle ils se concentrent. L'utilisation de systemes polymere/sel permet de reduire les couts. Une autre solution est l'utilisation d'un polymere soluble qui peut agir a la fois comme substrat et comme composant de la phase

Extractive Bioconversions in Aqueous Two-Phase Systems

Immobilized enzymes are suitable analytical reagents because of their selective molecular recognition and long-term operational performance. The use of enzymes as analytical reagents has considerably increased by their introduction in flow systems, e.g., flow injection analysis (FIA) and liquid chromatography (LC).' However, the number of compounds that can be enzymatically analyzed is limited by the physical or chemical properties of the substrates and products. In cases where none of the substrates or products are measurable, coupled sequential reactions open the possibility to determine one of these components. By the use of coupled reactions, additional advantages can be gained: (A) compounds involved in unfavorable equilibria may also be efficiently converted by shifting the equilibrium constant with the subsequent reaction, resulting in a system thermodynamically favorable and with a linear response range; (B) the selectivity of the analysis can be improved and therefore the accuracy, diminishing the risk of interferences; (C) inhibitory products can be continuously removed; and (D) the sensitivity is increased if any of the specimen (substrates, products, or cofactors) enters in a cyclic sequence with the possibility of signal amplification and recovering of cofactors.2

Coupled Enzyme Reactions in Flow Injection Analysis and Liquid Chromatographya

Increasing ethanol productivity from xylose in recombinant Saccharomyces cerevisiae by protein engineering

Most fermentative microorganisms grow well-under anaerobic conditions managing a balanced redox and appropriate energy metabolism, but a few species do exist in which cells have to cope with inadequate energy recovery or capture and/or redox balancing. Two cases of these species, i.e., the metabolically engineered Saccharomyces cerevisiae enabling it to ferment xylose and Lactobacillus reuteri fermenting glucose via the phosphoketolase pathway, are here used to introduce a quantification parameter to capture what limits the growth rate of these microorganisms under anaerobic conditions. This dimensionless parameter, the cofactor formation flux ratio (RJ ), is the ratio between the redox formation flux (JNADH+NADPH), and the energy carrier formation flux (JATP), which are mainly connected to the central carbon pathways. Data from metabolic flux analyses performed in previous and present studies were used to estimate the RJ -values. Even though both microorganisms possess different central pathways, a similar relationship between RJ and the specific growth rate (μ) was found. Furthermore, for both microorganisms external electron acceptors moderately reduced the RJ -value, thereby raising the μ accordingly. Based on the emerging profile of this relationship an interpretation is presented suggesting that this quantitative analysis can be applied beyond the two microbial species experimentally investigated in the current study to provide data for future targeted strain development strategies.

/pdf/close-to-the-edge-growth-restrained-by-the-nad-p-h-atp-5e6rmwfas8.pdf

Bärbel Hahn-Hägerdal

Papers

Extractive Bioconversions in Aqueous Two-Phase Systems

Coupled Enzyme Reactions in Flow Injection Analysis and Liquid Chromatographya

Increasing ethanol productivity from xylose in recombinant Saccharomyces cerevisiae by protein engineering

Close to the Edge: Growth Restrained by the NAD(P)H/ATP Formation Flux Ratio.

Evaluation of UF and RO in a cellulose saccharification process