Isolation of Acholeplasma laidlawii from Commercial, Serum-Free Tissue Culture Medium and Studies on Its Survival and Detection

This report documents the first isolation of Acholeplasma laidlawii from a commercial lot of serum-free Dulbecco basal medium. Experimental studies demonstrated survival of the organism for at least 1 year depending on the concentration of the contaminating organism as well as pH and temperature of storage of the serum-free medium. A comparison of isolation methods showed that concentration by filtration through 220-nm membrane filters and testing the filters for mycoplasma recovery, especially when using phenol red-diphasic Hayflick medium, was both sensitive and practical for the average laboratory.     

Effectiveness of fine root fingerprinting as a tool to identify plants of the Alps: Results of a preliminary study

To identify plants of the Alps through analysis of their roots is currently extremely difficult when using traditional identification methods such as dichotomous keys and/or illustrated atlases. Besides genetic analysis, other analytical methods, such as chromatographic analysis, could also be useful for root identification. Chromatographic fingerprints of root extracts of six species (Betula pendula, Picea abies, Fagus sylvatica, Larix decidua, Fraxinus excelsior and Corylus avellana) were analyzed in order to understand whether these species have a chromatographic fingerprint that identifies them, and hence to ascertain whether they can be identified by applying the method of analysis presented below. One hundred and sixty-two root samples were collected in various areas of the Alps and subjected to high-performance liquid chromatography (HPLC) analysis. Multivariate analysis techniques (e.g. cluster analysis) were employed for statistical analysis of chromatographic fingerprints. This study revealed that the chromatographic fingerprints of birch, spruce and larch samples were similar and that the method can therefore clearly identify the respective species. Instead, chromatographic fingerprint samples of beech, hazel and ash presented greater variability. Research proposals based on the results obtained in this study were also developed in order to implement and facilitate studies regarding plant roots.     

Habitat selection of European pine marten in Central Italy: from a tree dependent to a generalist species

Studies at small spatial scale are often fundamental to highlight the behavioural plasticity of a species and thus have important implications for conservation planning, in particular for species usually considered as habitat specialists. We investigated second-order habitat selection of the European pine marten in an area dominated by deciduous oak forest and open fields in central Italy, by radio-tracking 16 pine martens (eight males, eight females). Pine martens placed home ranges in areas with more open field than in the study area, whereas woodland (oak and conifer forests) comprised a smaller portion of the home range than predominant forest character of the studied area. Although the presence of the species in the open habitats has been documented, to our knowledge, our results provide the first evidence of home range establishment in this cover type by pine marten at population level. The combination of low predation risk and high availability of resources could allow pine martens to occupy open fields in our study area. We highlighted different individual strategies of habitat selection, with some individuals placing home ranges in areas with high forest coverage while others occupying open areas. We found no effects of sex and body condition on habitat selection, and this could indicate that in the study area, both forested and non-forested cover types, such as open fields, shrub and anthropic areas, can provide adequate food, overhead cover and resting sites for all individuals. Pine marten ability to occupy open fields seems thus more related to the behavioural flexibility of the species, rather than to the need to supplement dens and forage from complementary lower quality habitat. The high quality of the Mediterranean continental area studied could also explain the selection of open areas by the pine marten. Our results offer useful information on pine marten ecology and may be helpful for conservation management of this species in southern Europe.     

The role of macroinvertebrates for conservation of freshwater systems

Freshwater ecosystems are the most threatened ecosystems worldwide. Argentinian‐protected areas have been established mainly to protect vertebrates and plants in terrestrial ecosystems. In order to create a comprehensive biodiverse conservation plan, it is crucial to integrate both aquatic and terrestrial systems and to include macroinvertebrates. Here, we address this topic by proposing priority areas of conservation including invertebrates, aquatic ecosystems, and their connectivity and land uses. Location: Northwest of Argentina. We modeled the ecological niches of different taxa of macroinvertebrates such as Coleoptera, Ephemeroptera, Hemiptera, Megaloptera, Lepidoptera, Odonata, Plecoptera, Trichoptera, Acari, and Mollusca. Based on these models, we analyzed the contribution of currently established protected areas in the conservation of the aquatic biodiversity and we propose a spatial prioritization taking into account possible conflict regarding different land uses. Our analysis units were the real watersheds, to which were added longitudinal connectivity up and down the rivers. A total of 132 species were modeled in the priority area analyses. The analysis 1 showed that only an insignificant percentage of the macroinvertebrates distribution is within the protected areas in the North West of Argentina. The analyses 2 and 3 recovered similar values of protection for the macroinvertebrate species. The upper part of Bermejo, Salí‐Dulce, San Francisco, and the Upper part of Juramento basins were identified as priority areas of conservation. The aquatic ecosystems need special protection and 10% or even as much as 17% of land conservation is insufficient for species of macroinvertebrates. In turn the protected areas need to combine the aquatic and terrestrial systems and need to include macroinvertebrates as a key group to sustain the biodiversity. In many cases, the land uses are in conflict with the conservation of biodiversity; however, it is possible to apply the connectivity of the watersheds and create multiple‐use modules.     

A Ciprofloxacin Extended Release Tablet Based on Swellable Drug Polyelectrolyte Matrices

The aim of this work was the development of extended release tablets of 500 mg of ciprofloxacin based on swellable drug polyelectrolyte matrices (SDPM). A set of complexes of carbomer, ciprofloxacin and sodium, (CB–Cip)₅₀Na _x , having a molar ratio Cip/CB acid groups of 0.5 and variable proportions of Na⁺ was used to prepare SDPM. Characterization of complexes by FT-IR, powder X-ray diffraction and thermal analysis revealed that Cip, in its protonated form, is ionically bonded to the functional groups of CB. Rates of fluid uptake of (CB–Cip)₅₀Na _x matrices as well as Cip release in simulated gastric fluid were modulated by changes in the proportion of Na⁺ incorporated in the complexes. A direct correlation between fluid uptake and delivery rate was observed along the series of matrices. Release rates were modulated from 1.4 mg/min to 25 mg/min in going from (CB–Cip)₅₀Na₁₀ to (CB–Cip)₅₀Na₁₄. The analysis of kinetic data suggest that rates of swelling, ionic pair dissociation and drug diffusion play a role in the kinetic control of delivery. Complexes were satisfactorily prepared and processed together with small amounts of antiadherent and lubricant excipients to obtain a series of extended release SDPM tablets through the current tableting technology processes. Cip release from matrices was widely modulated by the composition of the complexes yielding a flexible system that allows selecting a composition that releases in 120 min 90% of the dose in simulated gastric fluid.     

Pine nut peroxidase immobilized on chitosan crosslinked with citrate and ionic liquid used in the construction of a biosensor

A biosensor based on the ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (BMI·Tf₂N) and a novel source of peroxidase (tissue from the pine nuts of Araucaria angustifolia) was constructed. This enzyme was immobilized on chitosan crosslinked with citrate and the biosensor used for the determination of rosmarinic acid by square-wave voltammetry. The peroxidase in the presence of hydrogen peroxide catalyzes the oxidation of rosmarinic acid to quinone and the electrochemical reduction of the product was obtained at a potential of +0.15 V vs. Ag/AgCl. Different analytical parameters influencing the biosensor response, that is, peroxidase units, pH, hydrogen peroxide concentration and parameters for the square-wave voltammetry (frequency, pulse amplitude and scan increment), were investigated. The best performance was observed for the biosensor under the following conditions: 1000 units mL⁻¹ peroxidase, pH 7.0 and 8.3 × 10⁻⁴ mol L⁻¹ hydrogen peroxide with a frequency of 30 Hz, pulse amplitude of 100 mV and scan increment of 5.0 mV. The biosensor gave a linear response to rosmarinic acid over the concentration range of 9.07 × 10⁻⁷ to 4.46 × 10⁻⁶ mol L⁻¹ with a detection limit of 7.25 × 10⁻⁸ mol L⁻¹. The recovery of rosmarinic acid in plant extracts ranged from 97.0% to 109.6% and the determination of this substance in these samples using the biosensor compared favorably with that using the capillary electrophoresis method.     

Equilibration kinetics in isolated and membrane-bound photosynthetic reaction centers upon illumination: a method to determine the photoexcitation rate

Kinetics of electron transfer, following variation of actinic light intensity, for photosynthetic reaction centers (RCs) of purple bacteria (isolated and membrane-bound) were analyzed by measuring absorbance changes in the primary photoelectron donor absorption band at 865 nm. The bleaching of the primary photoelectron donor absorption band in RCs, following a sudden increase of illumination from the dark to an actinic light intensity of I _exp, obeys a simple exponential law with the rate constant , in which α is a parameter relating the light intensity, measured in mW/cm², to a corresponding theoretical rate in units of reciprocal seconds, and k _rec is the effective rate constant of the charge recombination in the photosynthetic RCs. In this work, a method for determining the α parameter value is developed and experimentally verified for isolated and membrane-bound RCs, allowing for rigorous modeling of RC macromolecule dynamics under varied photoexcitation conditions. Such modeling is necessary for RCs due to alterations of the forward photoexcitation rates and relaxation rates caused by illumination history and intramolecular structural dynamics effects. It is demonstrated that the classical Bouguer–Lambert–Beer formalism can be applied for the samples with relatively low scattering, which is not necessarily the case with strongly scattering media or high light intensity excitation. An erratum to this article can be found at