Fungal enzyme sets for plant polysaccharide degradation

Enzymatic degradation of plant polysaccharides has many industrial applications, such as within the paper, food, and feed industry and for sustainable production of fuels and chemicals. Cellulose, hemicelluloses, and pectins are the main components of plant cell wall polysaccharides. These polysaccharides are often tightly packed, contain many different sugar residues, and are branched with a diversity of structures. To enable efficient degradation of these polysaccharides, fungi produce an extensive set of carbohydrate-active enzymes. The variety of the enzyme set differs between fungi and often corresponds to the requirements of its habitat. Carbohydrate-active enzymes can be organized in different families based on the amino acid sequence of the structurally related catalytic modules. Fungal enzymes involved in plant polysaccharide degradation are assigned to at least 35 glycoside hydrolase families, three carbohydrate esterase families and six polysaccharide lyase families. This mini-review will discuss the enzymes needed for complete degradation of plant polysaccharides and will give an overview of the latest developments concerning fungal carbohydrate-active enzymes and their corresponding families

Ferrotoroidic ground state in a heterometallic {Cr^IIIDy^III<inf>6</inf>} complex displaying slow magnetic relaxation

© 2017 The Author(s). Toroidal quantum states are most promising for building quantum computing and information storage devices, as they are insensitive to homogeneous magnetic fields, but interact with charge and spin currents, allowing this moment to be manipulated purely by electrical means. Coupling molecular toroids into larger toroidal moments via ferrotoroidic interactions can be pivotal not only to enhance ground state toroidicity, but also to develop materials displaying ferrotoroidic ordered phases, which sustain linear magneto-electric coupling and multiferroic behavior. However, engineering ferrotoroidic coupling is known to be a challenging task. Here we have isolated a {CrIIIDyIII6} complex that exhibits the much sought-after ferrotoroidic ground state with an enhanced toroidal moment, solely arising from intramolecular dipolar interactions. Moreover, a theoretical analysis of the observed sub-Kelvin zero-field hysteretic spin dynamics of {CrIIIDyIII6} reveals the pivotal role played by ferrotoroidic states in slowing down the magnetic relaxation, in spite of large calculated single-ion quantum tunneling rates

La lucha por el territorio en Nor Lípez : contexto, significado y proceso de una demanda de TCO en el altiplano meridional de Bolivia

Aunque su posición en parte parece extrema y uno podría tener la impresión de que las organizaciones y los derechos indígenas existan solamente gracias al sistema internacional, Brysk (1994) nos ofrece una mirada interesante sobre el nacimiento y desarrollo de los derechos indígenas. La marginalización nacional de los pueblos indígenas impidió la constitución de sus propios fuertes movimientos antes de los años 70. En 1971 se organizó la Conferencia de Barbados, en la que un grupo de antropólogos y abogados decidió promocionar las organizaciones indígenas mediante recursos internacionales

FATIGUE CRACK PROPAGATION BEHAVIOR OF 2091 T8 AND 2024 T3 UNDER CONSTANT AND VARIABLE AMPLITUDE LOADING

The fatigue crack propagation behavior of the damage tolerant 2091 T8 was compared with that of 2024 T3. Constant amplitude tests were performed in vacuum, air, and NaCl solution at R = 0.175 and in air at R = 0.7. The variable amplitude tests included periodic underloads superimposed on constant amplitude tests at R = 0.7, and periodic overloads in combination with low R-ratio tests. In general it was found that the crack propagation resistance of 2091 was slightly inferior in the lower ƊK-region as compared to 2024, but somewhat better at higher ƊK-values. For both alloys predicted propagation rates based on constant amplitude tests were lower than the experimentally measured values with periodic underloads. Periodic overloads resulted in crack growth retardation

Polarized Raman spectra of beryl and bazzite

The polarized Raman spectra of four different beryl crystals were studied at room temperature in the range from 30 to 4000 cm-1. The spectra show significant differences between the samples studied, and corrections are proposed for the reference Raman spectra of beryl previously reported by Adams and Gardner (1974). Type II water is observed in two crystals; the corresponding symmetric Raman stretching band at 3595 cm-1 is extremely strong for an impurity (about 20% of the strongest beryl lattice mode). Another, sharper, band of similar intensity at 3605 cm-1 could possibly originate from a hydroxyl stretching mode. Additional weaker bands are observed around 1600 cm-1 and 3600–3750 cm-1. The first polarized Raman spectra of bazzite are presented and discussed