Degradation of Sevin by soil microorganisms

Microorganisms capable of transforming the pesticide 1-naphthyl N-methyl-carbamate (Sevin) were isolated from soil. Three isolates were able to accelerate the hydrolysis of Sevin to 1-naphthol. Several unidentified intermediates were separated by thin-layer chromatography and also by following the decomposition of Sevin-methyl-¹⁴C. Since 1-naphthol is a biological as well as a chemical decomposition product of Sevin, its transformation by the isolated microbes was also studied. A fungus, identified as Fusarium solani, altered 1-naphthol rapidly. Whereas one strain of bacterium degraded the hydrolysis product gradually, another strain accumulated it under certain conditions. Mixed cultures of the investigated microbes were more effective in transforming Sevin than pure cultures, and this phenomenon was also observed with 1-naphthol as substrate with the exception of one bacterial strain.     

Vegetative propagation of Vitellaria paradoxa by grafting

Vitellaria paradoxa or karité is a wild fruit-bearing tree species of sudano-sahelian parklands that plays an important socio-economic role in Sub-Saharan Africa due to the commercial and domestic value of the fruits. Principal constraints of karité fruit production are: long juvenile phase, slow growth, genetic variability and lack of knowledge regarding the cultivation of the species. To address these constraints and to enhance productivity and quality, five methods of grafting (side cleft, top cleft, tongue, chip budding and side veneer), two methods of pre-treatment of scions and rootstocks (washing with 10% sodium hypochlorite to wash off latex and sterilise and a control without washing), and two methods of protection of grafts against desiccation (covering with white plastic sheet and aluminium foil) were tested. The results showed decreasing success of survival of grafts 16 weeks after grafting for the five grafting techniques: side cleft (86.1%), tongue (80.9%), top cleft (78.1%), chip budding (38.1%) and side veneer (20.7%) grafting methods. The results also showed May to be the optimum time for grafting, with high rates of shoot growth and survival of grafts. The average annual growth rate of grafts was 12.6 cm. The pre-treatment of scions with 10% sodium hypochlorite, however, had no significant effect on survival of scions. There was also no significant difference in survival of scions between the two methods of protection of grafts against desiccation (aluminium foil and plastic sheet). Two grafts produced fruits two years after grafting using side veneer grafting.This revised version was published online in November 2005 with corrections to the Cover Date.     

Efficacy of insecticide mixtures against larvae of Culex quinquefasciatus (Say) (Diptera: Culicidae) resistant to pyrethroids and carbamates

The efficacy of insecticide mixtures of permethrin (pyrethroid) and propoxur (carbamate) was tested by larval bioassays on two strains of Culex quinquefasciatus (Say), one resistant to pyrethroids and the other resistant to carbamates. The method consisted in combining one insecticide at the highest concentration causing no mortality (LC0) with increasing concentrations of the second one. The concentration-mortality regression lines were determined for permethrin and propoxur alone and in combination, and synergism ratios (SR) were calculated in order to determine the magnitude of an increase or decrease in efficacy with use of the mixtures. With the pyrethroid-resistant strain (BK-PER), the results showed that propoxur at LC0 significantly enhanced the insecticidal activity of permethrin (SR50 = 1.54), especially on the upper range of the concentration-mortality regression. Conversely, when permethrin at LC0 was tested with propoxur against the carbamate resistant strain (R-LAB), an antagonistic effect was observed (SR50 = 0.67). With the BK-PER strain, an increased oxidative detoxification (MFO) appeared to be the main mechanism responsible for the synergistic interaction. Nevertheless, antagonism in the R-LAB strain is probably due to a physiological perturbation implying different target sites for pyrethroid (ie sodium channel) and carbamate insecticides [ie acetylcholinesterase (EC 3.3.3.7) and choline acetyltransferase (EC 2.3.1.6)].     

Diffusion coefficient of CO(2) molecules as determined by (13)C NMR in various carbonated beverages

In this paper, the NMR technique was used, for the first time, to accurately determine the diffusion coefficient D of CO(2)-dissolved molecules in various carbonated beverages, including champagne and sparkling wines. This parameter plays an important role concerning the bubble growth during its rise through the liquid (see ref 3). The diffusion coefficient of CO(2)-dissolved molecules D was compared with that deduced from the well-known Stokes-Einstein equation and found to significantly deviate from the general trend expected from Stokes-Einstein theory, i.e, D(SE) proportional, variant 1/eta, where D(SE) is the Stokes-Einstein diffusion coefficient and eta the viscosity of the liquid medium.     

Electrochemical modification of the redox potential of pasteurized milk and its evolution during storage

Several modifications that occur in milk during its processing and storage are driven by different oxidation-reduction reactions. In this study, a smooth electrolytic process was used to modify the redox state of the active species of milk thereby creating a mean to control these reactions. Five electroreduction treatments (2, 4, 6, 8, and 10 V) were applied to pasteurized skim milk. Parameters such as redox potential, dissolved oxygen, pH, conductivity, and current intensity were monitored during the course of each treatment. The proposed technology allows modulation of the redox potential of milk. Significant decreases of redox potential (441-707 mV) and of dissolved oxygen (3.3-8.3 mg L(-1)) were obtained. However, the results suggest that only a short-term modulation is created and that natural "milk equilibrium" is reestablished after 4-5 days of storage depending on the voltage difference applied during the electrochemical treatment.     

Tubulin polyglutamylase enzymes are members of the TTL domain protein family

Polyglutamylation of tubulin has been implicated in several functions of microtubules, but the identification of the responsible enzyme(s) has been challenging. We found that the neuronal tubulin polyglutamylase is a protein complex containing a tubulin tyrosine ligase-like (TTLL) protein, TTLL1. TTLL1 is a member of a large family of proteins with a TTL homology domain, whose members could catalyze ligations of diverse amino acids to tubulins or other substrates. In the model protist Tetrahymena thermophila, two conserved types of polyglutamylases were characterized that differ in substrate preference and subcellular localization.     

Influence of packaging on the aroma stability of strawberry syrup during shelf life

Different types of packaging (glass bottle, PVC, and PET) were compared for the preservation of aroma quality of a strawberry syrup during shelf life. Esters, alcohols, and aldehydes were analyzed by solid-phase micro-extraction (SPME) and solvent extraction. During storage, hydrolysis of esters in acids and alcohols led to a modification of the aroma profile which can be explained by the replacement of "fruity" and "fresh" notes by "dairy note" in the syrup. Aroma compounds that are responsible for fruity notes, such as methyl cinnamate, methyl anthranilate, and methyl dihydrojasmonate, were strongly reduced after 90 days. This could be explained by a selective interaction of these compounds with the polymer matrix (PET or PVC). After 330 days, a later and important decrease of the "fruity notes" occurred in both PETs; so PVC2 and the glass bottle were found to be able to maintain a balanced aroma for long-term storage.     

The efficacy of small-scale conservation efforts, as assessed on Australian golf courses

Habitat remnants on urban green-space areas (i.e. parks, gardens and golf courses) sometimes provide refuge to urban-avoiding wildlife, leading some to suggest these areas may play a role in wildlife conservation if they are appropriately designed and managed. The high densities observed on some green-space areas may however be attributed to external influences. Localised efforts to enhance the habitat value of urban green-space areas may therefore have little more than a cosmetic effect. This study investigated environmental factors influencing bird, reptile, mammal and amphibian diversity on Australian golf courses to assess the efficacy of small-scale conservation efforts. Abundance and species richness did not simply reflect local habitat qualities but were instead, partly determined by the nature of the surrounding landscape (i.e. the area of adjacent built land, native vegetation and the number of connecting streams). Vertebrate abundance and species richness were however, also associated with on-site habitat characteristics, increasing with the area of native vegetation (all vertebrates), foliage height diversity and native grass cover (birds), tree density, native grass cover and the number of hollows (mammals), woody debris, patch width and canopy cover (reptiles), waterbody heterogeneity and aquatic vegetation complexity (frogs). Localised conservation efforts on small land types can benefit urban-avoiding wildlife. Urban green-space areas can provide refuge to urban-avoiding vertebrates provided combined efforts are made at patch (management), local (design) and landscape (planning) scales.     

Predominant expression of diploid mandarin leaf proteome in two citrus mandarin-derived somatic allotetraploid hybrids

Fusion of citrus diploid parental protoplasts generates allotetraploid hybrids which do not retain their parental traits with regard to leaf aroma compound biosynthesis. The aim of this study was thus to examine hybrid leaf proteomes in comparison with their parents. Leaf soluble proteins from two citrus allotetraploid hybrids (mandarin + lime and mandarin + kumquat) and their diploid parents (mandarin, lime, and kumquat) were submitted to 2-D gel electrophoresis. Leaf proteome maps of the tetraploid hybrids were compared with those of their parents on the basis of the presence/absence of spots and of their spot relative volumes. The two allotetraploid hybrid maps were found closer to that of their mandarin parent than to those of their nonmandarin parents in terms of the presence/absence of spots as well as at a quantitative level. This approach has to be related to the already observed dominance of mandarin in allotetraploids with regard to volatile compound biosynthesis in leaves.     

Abundance and distribution of<Emphasis Type="Italic"> Xylosandrus germanus</Emphasis> (Blandford 1894) (Coleoptera,Scolytidae) in Belgium: new observations and an attempt to outline its range

In Belgium, the current distribution and abundance of Xylosandrus germanus (Coleoptera, Scolytidae), a relatively new species to the Belgian fauna, is poorly known. Therefore, data on the range and population levels of this ambrosia beetle, on a regional and local scale respectively, are presented. Based on those results, the beetles range is discussed. Among the analysed biotic and abiotic factors that could influence the species settlement and population levels, climatic ones, and temperature in particular, seem to exert a crucial influence.