Bacterial diversity studied by next‐generation sequencing in a mature phototrophic Navicula sp‐based biofilm promoted into a shrimp culture system

The bacterial diversity of a phototrophic biofilm used as nutrient‐recycler into a shrimp aquaculture system and as direct food‐source for shrimp was studied by next‐generation sequencing, considering the 16S rDNA and metagenomics sequence classification using exact alignments. Biofilm was promoted by the modification of cabon:nitrogen ratio and by the addition of the diatom Navicula sp. as promoter. Results revealed a wide diversity of bacteria thriving into the biofilm; most of the bacteria detected in the biofilm belonged to the Proteobacteria (47%), Chlamydiae/Verrucomicrobia (11%), Bacteriodetes (8%), Planctomycetes (5%) Phylum. Species involved in the decomposition of organic matter, nitrogenous‐ and sulfurous metabolites were detected; moreover, filamentous species known as biomass‐bulking enhancers and producers of adhesin‐like compounds were also detected. Surprising results were also obtained by detecting both, strictly anaerobic and aerobic bacteria involved into the metabolism of nitrogenous compounds. Other species not belonging to the marine environment were also detected, but their role is unclear. Finally, the detection of most of these species may constitute a first case report for a phototrophic biofilm. The results suggest an important role of bacteria in this type of biofilm and a complex microbial‐interaction network.     

Adaptation of barley (Hordeum vulgare L.) to harsh Mediterranean environments

Summary Differences in development of the apex may be the reason for cultivar differences in adaptation of barley to terminal drought in Mediterranean environments. The present study was conducted to identify apical development patterns of barley adapted to terminal drought stressed Mediterranean environments and to determine plant characteristics which can be used as criteria to select for an adapted development. Thirty-five two-rowed barley (Hordeum vulgare L.) entries were grown at two sites in northern Syria (Tel Hadya and Breda) in 1988/89. Four apical development patterns were observed: a slow or fast vegetative development, depending on the vernalization requirement, combined with a slow or fast generative development, depending on the daylength response of the crop. Early heading was related to fast generative development. Leaf appearance rates on the main shoot were constant during a major part of the pre-anthesis period, but significant differences were observed among development patterns. Genotypic differences in main shoot tiller number were associated with differences in the onset of tiller appearance and not with differences in tiller appearance rate or final leaf number on the main shoot. Since vernalization requirements and daylength responses are largely independent of terminal drought stress, selection for an adapted phenology can be done in favourable environments. Morphological traits related to these responses (winter growth habit, cold tolerance, plant colour, growth vigour, heading date) can be used as criteria for selection for adaptation to low-rainfall Mediterranean environments.     

Insecticide formulations based on nicotine oleate stabilized by sodium caseinate

Organic farming and new trends toward the use of safer insecticides for crop protection have created new opportunities for botanical insecticides in the pesticide market. In this study, the botanical insecticide nicotine was formulated as a dispersion (20 vol %) stabilized by sodium caseinate, with nicotine oleate solutions used as the dispersed phase. The formulation showed a phase transition on increasing the nicotine oleate concentration, being an emulsion at 7.5-8.2 wt %, a suspo-emulsion at 8.2-9.7 wt %, and a suspension at 9.7-10.8 wt %. Biological activity, apparent viscosity, dispersion time, and protein surface coverage were dependent on nicotine oleate concentration. The emulsion with 8.2 wt % nicotine oleate and the suspo-emulsion with 8.7 wt % nicotine oleate were found to be the most appropriate formulations for insecticide purposes due to their high bioactivity, low viscosity, and low dispersion time. Nicotine oleate formulations showed good creaming and microbiological stability for at least 4 months without losing their biological activity.     

Sequence finishing and mapping of Drosophila melanogaster heterochromatin

Genome sequences for most metazoans and plants are incomplete because of the presence of repeated DNA in the heterochromatin. The heterochromatic regions of Drosophila melanogaster contain 20 million bases (Mb) of sequence amenable to mapping, sequence assembly, and finishing. We describe the generation of 15 Mb of finished or improved heterochromatic sequence with the use of available clone resources and assembly methods. We also constructed a bacterial artificial chromosome-based physical map that spans 13 Mb of the pericentromeric heterochromatin and a cytogenetic map that positions 11 Mb in specific chromosomal locations. We have approached a complete assembly and mapping of the nonsatellite component of Drosophila heterochromatin. The strategy we describe is also applicable to generating substantially more information about heterochromatin in other species, including humans.     

Photoprotective activity of Buddleja scordioides

The purpose of this study was to determine the photoprotective properties of the methanolic extract of Buddleja scordioides, as well as verbascoside and linarin which were isolated from this extract, and linarin acetate prepared in the laboratory. The photoprotective effect of substances against UV-B induced cellular death was evaluated by challenge experiments using Escherichia coli. Verbascoside and linarin acetate showed the highest protection. The sun protection factor (SPF) of the methanolic extract, linarin, linarin acetate, and verbascoside was evaluated by guinea pig bioassays. Verbascoside showed the largest SPF measurement.     

Equine Chorionic Gonadotropin (eCG) improves bucks’ semen quality during the nonbreeding season

In most goat breeds, testosterone serum concentration and semen quality decrease during the nonbreeding season. However, bucks reproductive activity may be stimulated with the administration of equine chorionic gonadotropin (eCG). Therefore, the aim of this study was to determine whether the repeated administration of eCG stimulates the reproductive status of bucks during the nonbreeding season. The study was performed with 19 bucks that were assigned to a group that was treated with eCG (GeCG) and an untreated control group (GCon). The GeCG bucks received an initial dose of 800 IU of eCG (Day 0), followed by four doses of 500 IU administered every 5 days beginning on Day 5. Serum testosterone and anti‐eCG antibody concentrations, testicular and seminal traits were determined until Day 60. Testosterone concentration (from Day 3 to 21: p < 0.0001), anti‐eCG titre (from Day 12 to 44: p ≤ 0.01), percentage of motile spermatozoa (Day 6: p = 0.006 and 14: p = 0.001) and of spermatozoa with progressive motility (Day 6: p = 0.01 and 14: p = 0.002) and the percentage of spermatozoa with functional membrane (Day 6: p = 0.02 and 22: p = 0.008) were higher in GeCG than in GCon bucks. Also in frozen‐thawed samples, the percentage of motile spermatozoa tended to be higher in GeCG than that of GCon bucks (p = 0.07). In conclusion, the administration of eCG during the nonbreeding season stimulated the secretion of testosterone and improved fresh and possibly frozen‐thawed semen quality. However, it also resulted in an increase in anti‐eCG antibody titre.     

A Radioisotopic Study of the Entry of Calcium Ion into the Maize Kernel During Nixtamalization

The entry of calcium ions from the nixtamalization solution into maize kernels over time was followed in model experiments using radiolabeled calcium ions, with autoradiographic evaluation of the kernels after different cooking and steeping times. Calcium ions immediately entered the pericarp and were rapidly fixed at the outer boundary of the endosperm, especially at the external surface of the germ. Entry of calcium into the endosperm occurred gradually after long steeping times, except in the case of broken kernels, for which massive invasion by calcium was observed. After extended steeping times, a moderate amount of calcium‐45 was evident in the germ. Specific perforation of the outer layers of the grains provided a defined route of facilitated entry of calcium into the endosperm. No fundamental difference with respect to penetrability by calcium ion was seen in a comparison between flint‐type grains and grains containing only floury endosperm.     

Pedigree comparison highlights genetic similarities and potential industrial values of sugarcane cultivars

Cultivar pedigrees from two sugarcane origins, 9 Argentine (AR) and 7 American (AM) have been reconstructed, and their genetic similarities (based on coefficient of parentage, COP, estimates) show an average of 0.206 ± 0.054. CP clones that enter the pedigrees of AM cultivars are parents or grandparents of AR cultivars, demonstrating that these genotypes have a strong genetic lineage in common. On average, AR pedigrees are smaller and contain less number of founding species than AM pedigrees. However, the lower height of the former is not explained by the different participation of founding species in the pedigrees. The presence of founding species in AR and AM pedigrees increases with the year of cultivar selection, indicating that more founding species entered the pedigree in recently selected cultivars than in older ones. The ancestry of the 16 cultivars trace back to 3 founding species: Saccharum officinarum, S. barberi, and S. spontaneum, with S. officinarum showing the greatest percentage of participation. As S. sinensis participates in 13 pedigrees and S. robustum in 3, the 5 founding species are present in 2 out of 16 pedigrees. Interestingly, the genus Sorghum enters the pedigree of LCP 85-384 pedigree. Industrial parameters assayed indicate that AR and AM cultivars were preferentially selected for their relatively high sucrose content and sugar yield in accordance with two facts: (i) the genetic background and the sucrose genes of sugarcane hybrids provided by the 68% of participation S. officinarum clones, and (ii) no clones of high fiber S. spontaneum have entered the pedigrees in earlier generations.     

Classification of wines produced in specific regions by UV-visible spectroscopy combined with support vector machines

Discriminating wines according to their denomination of origin using cost-effective techniques is something that attracts the attention of different industrial sectors. In search of simplicity, direct UV-visible spectrophotometric techniques and different multivariate statistical techniques are used with admissible results to characterize wine produced in specific regions. However, most of the reported classification methods do not exploit all of the statistical relations in the investigated dataset and are inherently affected by the presence of outliers. The aim of this paper is to test novel classification methods such as support vector machines as a means of improving the classification rate when UV-visible spectrophotometric methods are used to discriminate wines. The advantages of such a discrimination tool are demonstrated when classification rates are compared for a large number of Spanish red and white wines and classification rates above 96% are achieved. The proposed methodology also enables the selection of the most relevant wavelengths for sample discrimination. The proposed methodology also enables the selection of the most relevant wavelengths for sample discrimination.