Early evolution and ecology of camouflage in insects.

Taxa within diverse lineages select and transport exogenous materials for the purposes of camouflage. This adaptive behavior also occurs in insects, most famously in green lacewing larvae who nestle the trash among setigerous cuticular processes, known as trash-carrying, rendering them nearly undetectable to predators and prey, as well as forming a defensive shield. We report an exceptional discovery of a green lacewing larva in Early Cretaceous amber from Spain with specialized cuticular processes forming a dorsal basket that carry a dense trash packet. The trash packet is composed of trichomes of gleicheniacean ferns, which highlight the presence of wildfires in this early forest ecosystem. This discovery provides direct evidence of an early acquisition of a sophisticated behavioral suite in stasis for over 110 million years and an ancient plant-insect interaction.

An anamorph of the white-rot fungus Bjerkandera adusta capable of colonizing and degrading compact disc components.

A Geotrichum-like fungus isolated from a biodeteriorated compact disc (CD) was able to degrade in vitro the components of different CD types. The fungal hyphae inside the CD fragments grew through the aluminium layer and produced the solubilization of this metal. Furthermore, examination of CDs by scanning electron microscopy showed that the fungus was able to destroy the pits and lands structures grooved in the polycarbonate layer, confirming degradation of this aromatic polymer. The fungus secretes aryl-alcohol oxidase and Mn2+-oxidizing peroxidase, two kinds of oxidoreductases characteristic of ligninolytic basidiomycetes. Analysis of the ITS region of ribosomal DNA, as well as the morphological characteristics, the lack of sexual forms and the profile of enzymes secreted in liquid medium identified the fungus as a Geotrichum-like anamorph of Bjerkandera adusta (Willd.) P. Karst.

Enzymatic removal of free and conjugated sterols forming pitch deposits in environmentally sound bleaching of eucalypt paper pulp.

Free and conjugated sterols are among the main compounds responsible for pitch deposition in the manufacture of wood chemical pulps, making difficult the implementation of totally chlorine free bleaching (TCF) and closure of bleach plant circuits. In this work, the suitability of oxidative enzymes in efficiently removing sterols from eucalypt pulps is revealed. The enzymatic treatment was applied as an additional stage of an industrial-type TCF sequence for bleaching eucalypt kraft pulp. The pulp obtained after oxygen delignification was treated with a high-redox potential and thermostable fungal laccase using 1-hydroxybenzotriazole as an enzyme mediator. This pulp was further submitted to chelation and peroxide stages and compared with a control TCF pulp obtained using chemical reagents. The composition of the lipophilic extractives in the pulps and the corresponding liquids after the different stages was analyzed by gas chromatography and gas chromatography--mass spectrometry. Free sitosterol and sitosterol esters and glucosides, the major lipophilic compounds in eucalypt pulps, were completely removed during the laccase-mediator treatment. Only some intermediate products from sitosterol oxidation remained after the laccase stage, as well as in the final pulp. Pulp brightness was also improved due to the simultaneous removal of lignin by the laccase-mediator treatment.

Biodegradation of lignocellulosics: microbial, chemical, and enzymatic aspects of the fungal attack of lignin.

Wood is the main renewable material on Earth and is largely used as building material and in paper-pulp manufacturing. This review describes the composition of lignocellulosic materials, the different processes by which fungi are able to alter wood, including decay patterns caused by white, brown, and soft-rot fungi, and fungal staining of wood. The chemical, enzymatic, and molecular aspects of the fungal attack of lignin, which represents the key step in wood decay, are also discussed. Modern analytical techniques to investigate fungal degradation and modification of the lignin polymer are reviewed, as are the different oxidative enzymes (oxidoreductases) involved in lignin degradation. These include laccases, high redox potential ligninolytic peroxidases (lignin peroxidase, manganese peroxidase, and versatile peroxidase), and oxidases. Special emphasis is given to the reactions catalyzed, their synergistic action on lignin, and the structural bases for their unique catalytic properties. Broadening our knowledge of lignocellulose biodegradation processes should contribute to better control of wood-decaying fungi, as well as to the development of new biocatalysts of industrial interest based on these organisms and their enzymes.

Biodegradation of lignocellulosics: microbial, chemical, and enzymatic aspects of the fungal attack of lignin / Biodegradación de la lignocelulosa: aspectos microbiológicos, químicos y enzimáticos del ataque fúngico a la lignina

Wood is the main renewable material on Earth and is largely used as building material and in paper-pulp manufacturing. This review describes the composition of lignocellulosic materials, the different processes by which fungi are able to alter wood, including decay patterns caused by white, brown, and soft-rot fungi, and fungal staining of wood. The chemical, enzymatic, and molecular aspects of the fungal attack of lignin, which represents the key step in wood decay, are also discussed. Modern analytical techniques to investigate fungal degradation and modification of the lignin polymer are reviewed, as are the different oxidative enzymes (oxidoreductases) involved in lignin degradation. These include laccases, high redox potential ligninolytic peroxidases (lignin peroxidase, manganese peroxidase, and versatile peroxidase), and oxidases. Special emphasis is given to the reactions catalyzed, their synergistic action on lignin, and the structural bases for their unique catalytic properties. Broadening our knowledge of lignocellulose biodegradation processes should contribute to better control of wood-decaying fungi, as well as to the development of new biocatalysts of industrial interest based on these organisms and their enzymes (AU)

La madera es el principal material renovable en la Tierra y es utilizada en gran parte como material de construcción y en la fabricación de celulosa. Esta revisión describe la composición de los materiales lignocelulósicos y diversos procesos de alteración de la madera por parte de hongos, como el deterioro causado por los llamados hongos de podredumbre blanca, de podredumbre parda y de podredumbre blanda y por los hongos cromógenos o manchadores de la madera. También se tratan los aspectos químicos, enzimáticos y moleculares del ataque a la lignina por los hongos, que es clave en el deterioro de la madera. Se describen las técnicas analíticas modernas para investigar la degradación y la modificación del polímero de la lignina causadas por hongos, así como las diversas enzimas oxidativas (oxidoreductasas) que intervienen en la degradación de la lignina. Entre éstas se encuentran lacasas, peroxidasas ligninolíticas de alto potencial redox (lignina-peroxidasa, manganeso-peroxidasa y peroxidasas versátiles) y las oxidasas. Se destacan las reacciones catalizadas, su acción sinérgica sobre la lignina, y las bases estructurales de sus exclusivas propiedades catalíticas. Un mejor conocimiento de los procesos de biodegradación de la lignocelulosa debería contribuir a un mejor control de los hongos descomponedores de la madera, así como al desarrollo de nuevos biocatalizadores de interés industrial basados en estos organismos y sus enzimas (AU)