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.

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.

Lignocellulosic biomass has long been recognized as a potential sustainable source of mixed sugars for fermentation to biofuels and other biomaterials. Several technologies have been developed during the past 80 years that allow this conversion process to occur, and the clear objective now is to make this process cost-competitive in today's markets. Here, we consider the natural resistance of plant cell walls to microbial and enzymatic deconstruction, collectively known as "biomass recalcitrance." It is this property of plants that is largely responsible for the high cost of lignocellulose conversion. To achieve sustainable energy production, it will be necessary to overcome the chemical and structural properties that have evolved in biomass to prevent its disassembly.

http://science.sciencemag.org/content/sci/315/5813/804.full.pdf

Biomass recalcitrance: engineering plants and enzymes for biofuels production.

The End of History and the Last Man

Border Gateway Protocol (BGP) is the protocol backing the core routing decisions on the Internet. It maintains a table of IP networks or 'prefixes' which designate network reachability among autonomous systems (AS). Point of concern in BGP is its lack of effective security measures which makes Internet vulnerable to different forms of attacks. Many solutions have been proposed till date to combat BGP security issues but not a single one is deployable in practical scenario. Any security proposal with optimal solution should offer adequate security functions, performance overhead and deployment cost. This paper critically analyzes the deployment issues of best three proposals considering trade-off between security functions and performance overhead.

Comparative analysis of

The seven ages of wine

Ensuring sustainable management of water and soil for Australian grape and wine production

Les levures revetent une importance primordiale tout au long du processus de vinification ancien et complexe. Dans les fermentations spontanees, on observe un modele de croissance progressive de levures indigenes, les dernieres phases etant invariablement dominees par les souches Saccharomyces cerevisiae, qui tolerent l'alcool. Cette espece est universellement connue sous le nom de « levure de vin » et s'emploie tres frequemment pour amorcer et executer des fermentations viniques. La fonction premiere de la levure de vin consiste a catalyser la conversion rapide, complete et efficace des sucres du raisin en ethanol, en bioxyde de carbone et autres metabolites mineurs mais importants, sans odeurs etrangeres. Toutefois, etant donne l'exigence des pratiques modernes de vinification et la complexite des marches vinicoles, la demande de souches de levures de vin specialisees, presentant diverses caracteristiques oenologiques optimisees, ameliorees ou inedites, ne cesse d'augmenter. cette presentation a pour but de decrire la situation actuelle des levures de vin genetiquement ameliorees et les objectifs potentiels pour un developpement plus pousse des souches. A la lumiere des connaissances limitees sur les genomes complexes des levures de vin industrielles et des impressionnants obstacles a la resolution d'une multitude de problemes complexes d'ordre scientifique, technique, economique, commercial, securitaire, juridique et ethique, cette presentation precise egalement les reserves que suscitent certaines expectatives irrealistes a court terme. Toutefois, malgre l'actuel courant d'opposition contre les organismes genetiquement modifies (OGM) et les produits qui s'ensuivent, il serait desavantageux a long terme, tant pour le producteur que pour le consommateur de vin, d'ignorer plus avant les possibilites qu'offre la technique genetique dans le secteur international du vin. En science moderne du vin, cette technologie apporte de puissants outils pour obtenir des informations sur les aspects fondamentaux de la levure de vin et est souvent employee pour creer des prototypes genetiquement modifies permettant de resoudre des problemes complexes et de tester des hypotheses en vue d'atteindre ensuite les objectifs initiaux au moyen d'une strategie alternative, qui ne recourt pas aux OGM. Ces perspectives sont mises en lumiere par des exemples de prototypes de levure de vin genetiquement amelioree et par le role que les souches de levain pourraient jouer dans l'amelioration de la fermentation, du traitement et de la biopreservation des vins, ainsi que par leur capacite a ameliorer les effets salutaires et la qualite organoleptique du vin. A notre connaissance, aucune de ces levures de vin genetiquement ameliorees n'a encore ete utilisee a l'echelle commerciale; ce phenomene devrait persister tant que les consommateurs et les producteurs n'auront pas admis que les produits genetiquement modifies sont surs, de bonne qualite et bons pour la sante.

Development of superior wine yeast: current status and future opportunities to meet the consumer challenge

In this study, the aroma-production profiles of seven different Hanseniaspora strains, namely H. guilliermondii, H. meyeri, H. nectarophila, H. occidentalis, H. opuntiae, H. osmophila and H. uvarum were determined in a simultaneous co-inoculation with the wine yeast Saccharomyces cerevisiae Champagne Epernay Geisenheim (Uvaferm CEG). All co-inoculated fermentations with Hanseniaspora showed a dramatic increase in ethyl acetate levels except the two (H. occidentalis and H. osmophila) that belong to the so-called slow-evolving clade, which had no meaningful difference, compared to the S. cerevisiae control. Other striking observations were the almost complete depletion of lactic acid in mixed-culture fermentations with H. osmophila, the more than 3.7 mg/L production of isoamyl acetate with H. guilliermondii, the significantly lower levels of glycerol with H. occidentalis and the increase in certain terpenols, such as citronellol with H. opuntiae. This work allows for the direct comparison of wines made with different Hanseniapora spp. showcasing their oenological potential, including two (H. meyeri and H. nectarophila) previously unexplored in winemaking experiments.

/pdf/aroma-profiles-of-vitis-vinifera-l-cv-gewurztraminer-must-2bc6acqt.pdf

Isak S. Pretorius

Papers

The seven ages of wine

Ensuring sustainable management of water and soil for Australian grape and wine production

Development of superior wine yeast: current status and future opportunities to meet the consumer challenge

Aroma Profiles of Vitis vinifera L. cv. Gewürztraminer Must Fermented with Co-Cultures of Saccharomyces cerevisiae and Seven Hanseniaspora spp.

Wine-Omics: new platforms for the improvement of yeast strains and wine quality