Characterization of aerobic polycyclic aromatic hydrocarbon-degrading bacteria from Bizerte lagoon sediments, Tunisia

Aims: To characterize polycyclic aromatic hydrocarbon (PAH)‐degrading bacteria from sediments of the Bizerte lagoon, and to determine their ability to resist other pollutants such as antibiotics and heavy metals. Methods and Results: More than 100 strains were isolated for their ability to use fluoranthene as the sole carbon and energy source. Most of them showed antibiotic and heavy metal resistance; 20 representative strains were selected for further analysis. 16S rRNA coding sequences analysis showed that the majority of the selected bacteria (75%) were affiliated to the Gammaproteobacteria. The selected strains also utilized high molecular weight PAHs containing up to four benzene rings and showed different profiles of PAH substrate usage suggesting different PAH degradation pathways. These results are consistent with the fact that nah‐like genes and idoA‐like genes, involved in PAH degradation, were detected in 6 and 1 strains respectively. Conclusions: The Bizerte lagoon, polluted by many human activities, leads to the co‐selection of strains able to cope with multiple contaminants. Significance and Impact of the Study: Polluted areas are often characterized by the concomitant presence of organic pollutants, heavy metals and antibiotics. This study is one of the first showing bacterial strains adapted to multiple contaminants, a promising potential for the development of bioremediation processes.     

Molecular evidence for the occurrence of Contracaecum rudolphii A (Nematoda: Anisakidae) in shag Phalacrocorax aristotelis (Linnaeus) (Aves: Phalacrocoracidae) from Sardinia (western Mediterranean Sea)

Specimens of Contracaecum rudolphii Hartwich, 1964 (Nematoda: Anisakidae) from Phalacrocorax aristotelis (Linnaeus) from the Archipelago of La Maddalena (Sardinia, western Mediterranean Sea) were characterised genetically and compared with C. rudolphii A sensu D’Amelio et al. 1990 and C. rudolphii B sensu D’Amelio et al. 1990 from Phalacrocorax carbo sinensis (Blumenbach) from north-eastern Italy, and with C. rudolphii C sensu D’Amelio et al. 2007 from Phalacrocorax auritus (Lesson) from west-central Florida, USA. The sequencing of the small subunit of the mitochondrial ribosomal RNA gene (rrnS) and by polymerase chain reaction–restriction fragment length polymorphism (PCR-RFLP) analysis of the same gene and of the internal transcribed spacers (ITS) of nuclear ribosomal DNA (rDNA) allowed the identification of all specimens of C. rudolphii from P. aristotelis as C. rudolphii A. The results confirmed that the definition of genetic markers, following the analysis of nuclear ribosomal and mitochondrial DNA, provides quick and practical diagnostic tools for the detection of the 3 sibling species of C. rudolphii. The occurrence of C. rudolphii in P. aristotelis is reported for the first time from the Mediterranean area, improving the picture of the dispersal patterns of the populations of these piscivorous birds, and confirming the existence of different and isolated populations between the North and South European waters.     

Effects of plant height and row spacing on kenaf forage potential with multiple harvests

Kenaf (Hibiscus cannabinus L.) forage potential can be enhanced through its regrowth capacity and higher production in narrow rows. A field experiment was conducted in Matamoros, Coahuila, Mexico, during 2 growing seasons (2004 and 2005) to study the effects of plant height and row spacing on kenaf forage potential with multiple harvests. This study evaluated the effects of (1) 2 plant heights at cutting (1.0-1.2 m and 1.8-2.0 m) and (2) 4 inter row spacings (0.19, 0.38, 0.57 and 0.76 m) using a 2 x 4 factorial arrangement of treatments in a completely randomized block design with 4 replications. Dry matter (DM) and crude protein (CP) yields, DM partitioning, neutral detergent fiber (NDF) and CP concentrations were determined. Heights at cutting × row spacing interactions were not significant for the monitored variables (p>0.05). Kenaf response to treatments was only relevant for main effects (p≤0.05). Row spacing and plant height affected DM and CP yields (p≤0.05), whereas only plant height affected chemical composition and DM partitioning (p≤0.05). Dry matter (17.0%-26.0%), and CP (12.4%-15.6%) yields were higher (p≤0.05) when plant heights had reached 1.8 to 2.0 m. Row spacing reduction from 0.76 m to 0.38 and 0.19 m increased DM yield (20.4-33.4%) and CP yield (24.2-38.5%) (p≤0.05). Kenaf forage potential increases when planted in narrow rows and harvested 2 or 3 times during the growing season.     

Identification of quantitative trait loci for nitrogen use efficiency in maize

Intensively managed crop systems are normally dependent on nitrogen input to maximize yield potential. Improvements in nitrogen- use efficiency (NUE) in crop plants may support the development of cropping systems that are more economically efficient and environment friendly. The objective of this study was to map and characterize quantitative trait loci (QTL) for NUE in a maize population. In preliminary experiments, inbred lines contrasting for NUE were identified and were used to generate populations of F2:3 families for genetic study. A total of 214 F2:3 families were evaluated in replicated trials under high nitrogen (280 kg/ha) and low nitrogen (30 kg/ha) conditions in 1996 and 1997. Analysis of ear-leaf area, plant height, grain yield, ears per plant, kernels number per ear, and kernel weight indicated significant genetic variation among F2:3 families. The heritability of these traits was found to be high (h2=0.57–0.81). The mapping population were genotyped using a set of 99 restriction fragment length polymorphism (RFLP) markers. A linkage map of these markers was developed and used to identify QTL. Between two and six loci were found to be associated with each trait. The correspondence of several genomic regions with traits measured under nitrogen limited conditions suggests the presence of QTL associated with NUE. QTLs will help breeders to improve their maize ideotype of a low-nitrogen efficiency by identifying those constitutive and adaptive traits involved in the expression of traits significantly correlated with yield, such as ear leaf area and number of ears per plant. This revised version was published online in June 2006 with corrections to the Cover Date.     

Anomalies of the wolffian duct derivatives encountered at radical prostatectomy

Abnormalities of wolffian duct derivatives are usually encountered in young subjects. We identified 4 instances of embryologic malformations of these structures in patients who underwent radical prostatectomy (RP). The first patient had unilateral renal agenesis and a seminal vesicle cyst identified preoperatively by computed tomography. The seminal vesicle cyst was removed during RP. The second patient had renal agenesis and an ectopic ureter entering the right seminal vesicle. These were treated with ureterectomy during RP. The third patient had unilateral duplication of the vas deferens of no clinical consequence. Finally, the fourth patient had left-sided absence of both the vas deferens and seminal vesicle. The anatomy of the lower pelvis is most accurately shown on magnetic resonance imaging. Lower urinary tract malformations are an uncommon occurrence in males. Surgeons who perform numerous RPs will, however, find additional urologic pathologies during RP that may require consideration and tailored management.     

Preparative HPLC separation of methoxytetralins, ligands for melatonin receptors, containing two chiral centers with polysaccharide chiral stationary phases. Determination of enantiomeric purity

Preparative chromatography was used to obtain approximately 200 mg of each of the four individual isomers of the three methoxytetrahydronaphthalenic derivatives, new agonist and antagonist ligands for melatonin receptors to be tested for binding. The mobile and stationary phases were chosen to achieve best resolution in shorter runtime. Enantiomeric purity was verified and quantified using normal and reversed phase methodology on cellulose CSPs. Enantiomer elution order was analysed and discussed. Limit of detection (LOD) and limit of quantification (LOQ) were calculated.