Evaluation of basidiomycetous fungi for pretreatment of contaminated soil

BACKGROUND: For most dioxin‐contaminated sawmill soils, combustion is recommended. However, the process may be inefficient if the soil has a high organic matter content. The use of saprotrophic basidiomycetous fungi is an alternative for pretreatment of this kind of soil. A total of 147 fungi were evaluated for their ability to grow in sawmill soil. From this screening, the best soil colonizing fungi were selected to study their enzyme activities and degradation of soil organic matter. Pine (Pinus sylvestris) bark was used as a co‐substrate to propagate the fungi into the soil. The activities of manganese peroxidase (MnP), laccase, endo‐1,4‐β‐glucanase, endo‐1,4‐β‐xylanase, and endo‐1,4‐β‐mannanase were analysed from the inocula and fungal treated soil. RESULTS: The screening revealed that 56 out of 147 fungi were able to grow in non‐sterile soil, and most of them were litter‐decomposing fungi (LDF). In pine bark cultures, the highest enzyme activities were observed with Phanerochaete velutina, which produced 5 U g^?1 of MnP. The activity of endo‐1,4‐β‐glucanase was generally higher than that of other hydrolytic enzymes. The highest carbon loss from soil with a high organic matter content was achieved by P. velutina (3.4%) and Stropharia rugosoannulata (2.4%). CONCLUSIONS: Many LDF, and in addition the white‐rot fungus P. velutina, are potential degraders of soil organic matter since they showed good growth and respiratory activity. Pine bark was a suitable lignocellulosic co‐substrate and a good promoter of MnP activity. Copyright © 2009 Society of Chemical Industry     

A survey of ellagitannin content in raspberry and blackberry cultivars grown in Trentino (Italy)

This study describes the first application of a new procedure for acid hydrolysis of Rubus ellagitannins in methanol, which allows quantification of all the major reaction products (ellagic acid, methyl-sanguisorboate, methyl gallate and an unknown ellagic acid derivative) and estimation of the mean degree of polymerization (mDP) of Rubus ellagitannins. The ellagitannins of 21 raspberry and 15 blackberry cultivars produced in Trentino, Italy during 2005 were extracted and characterised. The total content of ellagitannins was shown to vary by a factor of 2 among raspberry cultivars and by a factor of 4 among blackberry cultivars.     

Assimilation of traumatic experiences and physical-health outcomes: Cautions for the Pennebaker paradigm.

This study reports an application of the assimilation model, a theory of psychotherapeutic change, to an analogue study in which 43 students were asked to write for 20 minutes a day for 4 days ("Pennebaker paradigm") about a traumatic experience. Contrary to expectations based on previous research, participants who showed the greatest change in assimilation level and achieved the highest levels of assimilation during the study subsequently had more health-center visits than participants whose assimilation was less. Qualitative exploratory work suggested that there may be negative consequences of exposing traumatic experiences in the absence of supportive therapy to contain and fully integrate the experiences. A more measured approach to the benefits of brief exposition of traumatic experiences may be warranted. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Selective deposits of versican in the extracellular matrix of restenotic lesions from human peripheral arteries

Although a large percentage of the volume of human restenotic arterial lesions is occupied by extracellular matrix (ECM), the composition and organization of this ECM are not well characterized. In this study, restenotic segments taken from 30 human peripheral arteries by directional atherectomy at times ranging from 13 days to 36 months after angioplasty were analyzed for specific patterns of ECM composition and organization by light and electron microscopic histochemistry and immunohistochemistry. Histochemical analysis revealed the presence of distinct zones, enriched either in proteoglycans or fibrillar collagen. Most sections contained these regions juxtaposed to each other. The frequency of these two distinct ECMs did not change as a function of time after angioplasty. The collagen-rich zone usually contained elongated smooth muscle cells spaced close together except in regions resembling fibrous plaques. The proteoglycan-rich ECM contained both elongated and stellate-shaped smooth muscle cells randomly arranged and separated by wide distances. This region resembled the loose-connective-tissue-containing myxoid region typical of restenotic lesions. Immunohistochemical analysis of these regions revealed that the proteoglycan-containing zone stained intensely for versican, a large interstitial chondroitin sulfate proteoglycan, whereas the collagen-containing areas were mostly negative for versican but positive for type I collagen. The versican-positive regions also immunostained for biglycan, a small leucine-rich dermatan sulfate proteoglycan, and sparsely for elastin. However, both of these ECM molecules were present in the versican-negative type I collagen-positive regions of the lesions. These results suggest that the development of restenotic lesions involves localized deposits of specific ECM molecules that may play a role in the asymmetric renarrowing of this tissue after angioplasty.     

Effect of coffee physical structure on volatile release

The mechanisms of volatile release from soluble coffee powders with different roasting degrees were studied. The presence of volatiles in the headspace during coffee humidification was analyzed by gas chromatography. Small amounts of volatiles were observed at low water activities (a_w), independently from the roasting degree; as the a_w increased headspace volatiles rose and then decreased as the moisture further increased. The changes in a_w and volatiles went along with the changes of coffee structure from a free-flowing powder to a sticky viscous fluid. The mechanism of volatiles release was controlled by both kinetic and thermodynamic factors. The former prevailed at low a_w in glassy systems; while the latter became important at high a_w when, due to increased mobility, equilibrium conditions were approached. Modified state diagrams were used to predict the critical temperature and a_w at which structural collapse and volatile release occurred. As far as equilibrium condition was achieved, coffee volatiles were partially re-adsorbed in the liquid phase.     

Characterisation of gold kiwifruit pectin isolated by enzymatic treatment

Pectin was extracted from gold kiwifruit by four commercial enzyme preparations (Celluclast 1.5 L, Cytolase CL, Cellulyve TR 400 and NS33048). The chosen enzymes were used either in single or in combination, with and without protease addition. The recovered pectin was characterised and compared for the yield, total nonstarch polysaccharide and neutral sugar composition, protein and ash, pectin, molecular weight distribution and the viscosity. Results indicated that enzyme‐extracted gold kiwifruit pectin was rich in galacturonic acid. Purified pectin yield, and their physicochemical composition and rheological property (viscosity), was significantly affected by the type of enzyme used. The pectin extracted by Celluclast 1.5 L demonstrated to be the most viscous and recorded the highest in molecular weight (M_w) (1.65 × 10⁶ g mol^–1) compared with the other extracts. The extract M_w and their distribution were discussed and related to their viscosity behaviour.     

Fractional channel reservation in mobile communication systems

A fractional channel reservation scheme is proposed. In conventional channel reservation schemes, the number of channels reserved for handoff calls has always been an integer. The proposed fractional channel reservation algorithm can be used to finely control the communication service quality. By varying the number of reserved channels for handoff calls by fractions of one     

Environmental impact of castor oil catalytic transfer hydrogenation

In the vegetable oil chemical industry, hydrogenation is one of the most important processes. An alternative method for vegetable oil hydrogenation is the use of catalytic transfer hydrogenation (CTH), which can utilize organic molecules as hydrogen donors at ambient pressure. These alternative processes should be optimized in relation to the variables required for a good conversion and impacts should also be known to be minimized. An assessment of the environmental impact of laboratory scale chemical processes is an important tool to improve the technological aspects of a process (increased yields, reduced production times, lower costs) and it can also lead to the creation of a cleaner technology. Using the Leopold Matrix, we have succeeded in developing a more efficient and cleaner process for the CTH of castor oil using Raney Ni as a catalyst and cyclohexene or isopropanol as a hydrogen donor solvent. The results of the technical and environmental assessments showed that the extent of conversion for the unsaturation reaction was high (>99 %), and the environmental impact of the process could be significantly reduced to create a cleaner technology. It was found, after process optimization, that the remaining environmental impacts were negative (67.48 %), local (78.95 %), temporary (95.33 %), direct (80.12 %), and reversible (95.32 %).