Membrane-assisted processing of xylooligosaccharide-containing liquors

Liquors from rice husk autohydrolyis, containing xylooligosaccharides, other saccharides, and nonsaccharide compounds, were subjected to two selected processing schemes to increase the proportion of substituted xylooligosaccharides in refined liquors. Nanofiltration through a ceramic membrane with a molecular mass cutoff of 1000 Da allowed simultaneous concentration and purification; this latter derived from the preferential removal of monosaccharides and nonsaccharide compounds. When liquors were nanofiltered to achieve a volume reduction factor of 5 operating at a transmembrane pressure of 14 bar, 58.6% of the nonsaccharide components and 20.9-46.9% of monosaccharides were kept in retentate, in comparison with 92% of xylooligosaccharides and glucooligosaccharides. When nanofiltered liquors were subjected to double ion-exchange processing, a final product with a nonsaccharide content near 9 kg/100 kg of nonvolatile components was obtained at a yield of 10.90 kg/100 kg oven dry rice husks. Alternatively, when nanofiltered liquors were subjected to ethyl acetate extraction and further double ion-exchange processing, a purified product with a nonsaccharide content of 5.66 kg/100 kg of nonvolatile components was obtained at a yield of 9.94 kg/100 kg oven dry rice husks. The nonsaccharide components remaining in the final concentrate were mainly made up of phenolic and nitrogen-containing compounds.     

Local illegal trade reveals unknown diversity and involves a high species richness of wild vascular epiphytes

Traffic of plants and animals of wild origin is a major threat to biological diversity creating a need for legal protection of traded species. Epiphytic vascular plants are a diverse guild which provides the horticultural market with many species. Many epiphytes are under protection intended to stop illegal trade at international and local levels. To measure the richness and volume of the epiphytes that are traded illegally on a local level, we monitored an illegal sale point in Xalapa, Veracruz, Mexico for 85 weeks. We recorded 27 traders, 207 species and 7598 plants. Nineteen species were known for Mexico but not native to Veracruz; two others had been collected in Veracruz but had never been reported before for Mexico. About 25% of epiphyte richness in Veracruz and 47% of the State’s epiphytic orchids are traded illegally. Most of the species traded could have been harvested in lower montane cloud forest (105 species), however all vegetation types of central Veracruz are potential epiphyte sources. Twenty-seven species protected by Mexican law were traded, along with 41 species endemic to Mexico and six endemic to Veracruz. We concluded that on a local level, the richness and volume of epiphytes illegally traded are high; in fact, the volume of orchids traded equals the annual average volume of legal Mexican orchid exports. Illegal epiphyte trade occurs worldwide, making necessary crucial increases of protective measures and the development of sustainable ways of harvesting epiphytes.     

Proteolytic properties of Funastrum clausum latex

As part of a screening of latex endopeptidases from plants growing in Argentina, the presence of proteolytic activity in the latex of Funastrum clausum stems is reported. The proteases present in the crude extract showed the main characteristics of the cysteine proteolytic class, i.e. optimum pH at alkaline range, isoelectric point (pI) higher than 9.0, and inhibition of proteolytic activity by thiol blocking reagents. A remarkable thermal stability was also evident in the crude extract. Endosterolytic preference tried on p-nitrophenyl esters of N-alpha-carbobenzoxy-L-amino acids was higher for the alanine, asparagine and tyrosine derivatives. Preliminary peptidase purification by two-step ionic exchange showed the presence of two proteolytic fractions with molecular masses of approximately 24.0 kDa according to SDS-PAGE.     

Energy Basal Levels and Allocation among Lipids, Proteins, and Carbohydrates in Enchytraeus albidus: Changes Related to Exposure to Cu Salt and Cu Nanoparticles

Energy intake and allocation are mainly used to maintain body functions, such as locomotion, growth, and reproductive output. It has been observed that environmental pollutants can affect the energy allocation either due to a cost of handling toxicants or because the toxicant interacts with the storage processes within the organisms. Less than a handful of studies are available reporting the effect of toxicants on energy reserves in enchytraeids and no studies have dealt with the influence of nanomaterials. The present paper shows results on the basal energy reserves (lipids, carbohydrates, and proteins) in Enchytraeus albidus and the influence of copper (Cu) salt and Cu nanoparticles on these reserves for two exposure durations. The energy allocation levels follow what has been reported for other worm species, although lower carbohydrate levels were observed. There were clear differences between worms exposed to control soils and those exposed to Cu for 3 weeks, but no difference after 6 weeks exposure. There was no apparent difference between the impacts of the two Cu exposure forms.