Vienna University of Technology

About: Vienna University of Technology is a education organization based out in Vienna, Austria. It is known for research contribution in the topics: Laser & Cloud computing. The organization has 16723 authors who have published 49341 publications receiving 1302168 citations.

Cellulases and beyond: the first 70 years of the enzyme producer Trichoderma reesei.

Abstract: More than 70 years ago, the filamentous ascomycete Trichoderma reesei was isolated on the Solomon Islands due to its ability to degrade and thrive on cellulose containing fabrics. This trait that relies on its secreted cellulases is nowadays exploited by several industries. Most prominently in biorefineries which use T. reesei enzymes to saccharify lignocellulose from renewable plant biomass in order to produce biobased fuels and chemicals. In this review we summarize important milestones of the development of T. reesei as the leading production host for biorefinery enzymes, and discuss emerging trends in strain engineering. Trichoderma reesei has very recently also been proposed as a consolidated bioprocessing organism capable of direct conversion of biopolymeric substrates to desired products. We therefore cover this topic by reviewing novel approaches in metabolic engineering of T. reesei.

Secondary organic aerosol formation in the atmosphere via heterogeneous reaction of gaseous isoprene on acidic particles

Abstract: [1] Water-soluble macromolecular substances with spectral properties of “humic-like substances” (HULIS) were recently found to form the major identified fraction of the organic aerosol at urban and rural sites in Europe. With primary sources identified so far (e.g., biomass combustion) it is not possible to explain the observed HULIS levels in Europe, therefore there is an ongoing search for other sources - which form HULIS in situ in the atmosphere. Here we show that secondary aerosol formation of atmospheric polymers occurs by heterogeneous reaction of isoprenoid or terpenoid emissions in the presence of a sulfuric acid aerosol catalyst. Competing oxidants such as ozone or the presence of humidity decreased the reaction yield, but the formation of humic–like substances was not disabled. Calculations indicate that the presented reaction pathway could be an additional source for HULIS in the continental aerosol.

Quantum state-controlled directional spontaneous emission of photons into a nanophotonic waveguide

Abstract: Nanoscale confinement in an optical fibre induces coupling between a photon’s spin and orbital angular momentum. Here, the authors use this effect to control the direction of photons spontaneously emitted from trapped caesium atoms into a nanofibre.

SIMON-A simulator for single-electron tunnel devices and circuits

Abstract: SIMON is a single electron tunnel device and circuit simulator that is based on a Monte Carlo method. It allows transient and stationary simulation of arbitrary circuits consisting of tunnel junctions, capacitors, and voltage sources of three kinds: constant, piecewise linearly time dependent, and voltage controlled. Cotunneling can be simulated either with a plain Monte Carlo method or with a combination of the Monte Carlo and master equation approach. A graphic user interface allows the quick and easy design of circuits with single-electron tunnel devices. Furthermore, as an example of the usage of SIMON, we discuss the essential problem of random background charge and present possible solutions.

Opportunities and challenges for combining chemo- and biocatalysis

Abstract: The past decade has seen a substantial increase in successful examples of the combination of chemo- and biocatalysis for multistep syntheses. This is driven by obvious advantages such as higher yields, decreased costs, environmental benefits and high selectivity. On the downside, efforts must be undertaken to combine the divergent reaction conditions, reagent tolerance and solvent systems of these ‘different worlds of catalysis’. Owing to progress in enzyme discovery and engineering, as well as in the development of milder and more compatible conditions for operating with various chemocatalysts, many historical limitations can already be overcome. This Review highlights the opportunities available in the chemical space of combined syntheses using prominent examples, but also discusses the current challenges and emerging solutions, keeping in mind the fast progress in transition metal-, organo-, photo-, electro-, hetero- and biocatalysis. Chemical and biological catalysts provide distinct advantages and disadvantages to the synthetic chemist. This Review focuses on efforts to combine chemo- and biocatalysts, outlining the opportunities achievable by this approach and also efforts to overcome any incompatibilities between these different systems.