Enzyme-based DNA extraction from zoospores of ruminal fungi

We report here a rapid, efficient and simple method for the extraction of high molecular weight DNA from zoospores of Neocallimastix frontalis EB188. This anaerobic fungus, isolated from bovine digesta, effectively degrades plant fiber in vitro (Barichievich et al. 1990. Appl. Env. Micro. 56:43-48). Our interest in ruminal fungi stems from their ability to degrade wood materials (Joblin et al. 1989. FEMS Micro. Lett. 56:119-122) and their potential use in biomass saccharification. Zoospore DNA synthesis is of particular interest to our laboratory. It is these motile zoospores which colonize and degrade plant materials (Mountfort 1987. FEMS Micro. Rev. 46:501-508). To detail fully this metabolic event, it will be necessary to extract nucleic acids from zoospores. Such procedures have not been reported in the literature. Using acetone drying and enzymatic removal of cell walls, we have isolated high molecular weight DNA from very small amounts of culture. The procedure takes less than one hour and DNA yields are high. The DNA is readily cut with restriction endonucleases and religated efficiently but is otherwise stable. Electrophoretic analysis of the DNA confirmed the presence of repetitive sequences. This procedure will aid the study of DNA replication, DNA repair and DNA RFLP analysis of various strains using small (\u3c1 ml) cultures

An easy synthesis for preparing bio-based hybrid adsorbent useful for fast adsorption of polar pollutants

For the first time, γ-Al2O3 and Bio-Based Substances (BBS) hybrids (A-BBS) were prepared through a simple electrostatic interaction occurring between alumina, used as a support, and BBS (Bio-Based Substance from composted biowastes) carrying positive and negative charges, respectively. We evaluated the optimal amount of BBS to be immobilized on the support and the stability of the resulting A-BBS in order to use this novel hybrid material as an adsorbent for the removal of polar pollutants. Characterization was carried out by X-Ray Diffraction (XRD) for evaluating the crystal structure of the support, Fourier transform infrared spectroscopy (FT-IR) to evidence the presence of BBS on the hybrid material, thermogravimetric analysis (TGA) to measure the thermal stability of the hybrid materials and quantify the BBS amount immobilized on the support, N2 adsorption at 77 K for the evaluation of the surface area and porosity of the systems, Zeta potential measurements to evaluate the effect of BBS immobilization on the surface charge of the particles and choose the substrates possibly interacting with them. Firstly, we tested the adsorption capability of three samples differently coated with BBS toward cationic species considering various adsorbate/adsorbent ratio. Crystal Violet (CV) was chosen as model pollutant to compare the performance of the hybrid materials with those of other materials described in the literature. The adsorption data were modeled by Langmuir and Freundlich adsorption isotherms. Then, we studied the adsorption capability of the developed material towards molecules with different structures; for this purpose, two contaminants of emerging concerns (carbamazepine and atenolol) were tested. The results indicate that A-BBS could be applied in wastewater treatment for the removal of a significant amount of polar species. In addition, a comparison with literature data concerning CV adsorption was carried out in order to evaluate the environmental impact of synthetic routes used to prepare different adsorbents

Begging and parental care in relation to offspring need and condition in the barn swallow (Hirundo rustica)

Parents are selected to maximize their fitness by allocating care among their progeny in relation to the differential reproductive value of offspring. Nestlings have been hypothesized to signal need for parental care reliably through their begging behavior, but offspring condition as reflected by their reproductive value may likewise affect begging and hence provisioning. We assessed the relative importance of need and condition in determining begging behavior and feeding rate of nestling barn swallows (Hirundo rustica) through short-term starvation, a challenge to their immune system with a foreign antigen negatively affecting condition, and brood size manipulation. Food deprivation but not condition or brood size manipulation increased nestling begging rate. Parents fed offspring depending on both need and condition but only when feeding broods that were reduced or of normal size. In enlarged broods, offspring received less food per capita than in reduced broods, and parents did not discriminate among nestlings relative to their need or condition. Thus, nestlings signal their need by increased solicitation. Parents allocate food to offspring dependent on both need and condition, with these effects depending on parental workload as determined by experimental brood size