"Super p53" mice exhibit enhanced DNA damage response,are tumor resistant and age normally

The tumor suppressor p53 is critical in preventing cancer due to its ability to trigger proliferation arrest and cell death upon the occurrence of a variety of stresses, most notably, DNA damage and oncogenic stress. Here, we report the generation and characterization of mice carrying supernumerary copies of the p53 gene in the form of large genomic transgenes. Prior to this, we demonstrate that the p53 transgenic allele (p53-tg), when present in a p53-null genetic background, behaves as a functional replica of the endogenous gene. "Super p53" mice, carrying p53-tg alleles in addition to the two endogenous alleles, exhibit an enhanced response to DNA damage. Importantly, "super p53" mice are significantly protected from cancer when compared with normal mice. Finally, in contrast to previously reported mice with constitutively active p53, "super p53" mice do not show any indication of premature aging, probably reflecting the fact that p53 is under normal regulatory control. Together, our results prove that cancer resistance can be enhanced by a simple genetic modification and in the absence of undesirable effects.     

CYP175A1 from<Emphasis Type="Italic"> Thermus thermophilus</Emphasis> HB27, the first β-carotene hydroxylase of the P450 superfamily

The biological function of thermostable P450 monooxygenase CYP175A1 from Thermus thermophilus HB27 was studied by functional complementation in Escherichia coli. The gene product of CYP175A1 added hydroxyl groups to both rings of -carotene to form zeaxanthin (,-carotene-3,3-diol) in E. coli, which produces -carotene due to the Erwinia uredovora carotenoid biosynthesis genes. In addition, spectroscopic methods revealed that E. coli carrying CYP175A1 and the cDNA of the Haematococcus pluvialis carotene ketolase was able to synthesise hydroxyechinenone. The predicted amino acid sequence of the enzyme from T. thermophilus does not show substantial similarity with other known -carotene hydroxylases, but 41% with the cytochrome P450 monooxygenase from Bacillus megaterium (CYP102A1, P450 BM3). It is concluded that CYP175 A1 represents a new type of -carotene hydroxylase of the P450 superfamily.     

Pectinase production by <Emphasis Type="Italic">Aspergillus giganteus</Emphasis> in solid-state fermentation: optimization,scale-up,biochemical characterization and its application in olive-oil extraction

The application of pectinases in industrial olive-oil processes is restricted by its production cost. Consequently, new fungal strains able to produce higher pectinase titers are required. The aim of this work was to study the capability of Aspergillus giganteus NRRL10 to produce pectinolytic enzymes by SSF and evaluate the application of these in olive-oil extraction. A. giganteus was selected among 12 strains on the basis of high pectinolytic activity and stability. A mixture composed by wheat bran, orange, and lemon peels was selected as the best substrate for enzyme production. Statistical analyses of the experimental design indicated that pH, temperature, and CaCl₂ are the main factors that affect the production. Subsequently, different aeration flows were tested in a tray reactor; the highest activity was achieved at 20 L min^?1 per kilogram of dry substrate (kgds). Finally, the pectinolytic enzymes from A. giganteus improved the oil yield and rheological characteristics without affecting oil chemical properties.     

Global distribution and vertical patterns of a prymnesiophyte–cyanobacteria obligate symbiosis

A marine symbiosis has been recently discovered between prymnesiophyte species and the unicellular diazotrophic cyanobacterium UCYN-A. At least two different UCYN-A phylotypes exist, the clade UCYN-A1 in symbiosis with an uncultured small prymnesiophyte and the clade UCYN-A2 in symbiosis with the larger Braarudosphaera bigelowii. We targeted the prymnesiophyte–UCYN-A1 symbiosis by double CARD-FISH (catalyzed reporter deposition-fluorescence in situ hybridization) and analyzed its abundance in surface samples from the MALASPINA circumnavigation expedition. Our use of a specific probe for the prymnesiophyte partner allowed us to verify that this algal species virtually always carried the UCYN-A symbiont, indicating that the association was also obligate for the host. The prymnesiophyte–UCYN-A1 symbiosis was detected in all ocean basins, displaying a patchy distribution with abundances (up to 500 cells ml⁻¹) that could vary orders of magnitude. Additional vertical profiles taken at the NE Atlantic showed that this symbiosis occupied the upper water column and disappeared towards the Deep Chlorophyll Maximum, where the biomass of the prymnesiophyte assemblage peaked. Moreover, sequences of both prymnesiophyte partners were searched within a large 18S rDNA metabarcoding data set from the Tara-Oceans expedition around the world. This sequence-based analysis supported the patchy distribution of the UCYN-A1 host observed by CARD-FISH and highlighted an unexpected homogeneous distribution (at low relative abundance) of B. bigelowii in the open ocean. Our results demonstrate that partners are always in symbiosis in nature and show contrasted ecological patterns of the two related lineages.     

Discovery of the imidazo[1,5-a][1,2,4]-triazolo[1,5-d][1,4]benzodiazepine scaffold as a novel,potent and selective GABAA α5 inverse agonist series

Through iterative design cycles we have discovered a number of novel new classes where the imidazo[1,5-a][1,2,4]-triazolo[1,5-d][1,4]benzodiazepine was deemed the most promising GABA_A α5 inverse agonist class with potential for cognitive enhancement. This class combines a modest subtype binding selectivity with inverse agonism and has the most favourable molecular properties for further lead optimisation towards a central nervous system (CNS) acting medicine.     

Occurrence of Drug-Resistant Bacteria in Two European Eel Farms

The occurrence of strains that are resistant to oxolinic acid, oxytetracycline, sulfamethoxazole-trimethoprim, and nitrofurantoin among heterotrophic bacteria, including human and fish pathogens, in two freshwater eel farms was investigated. High levels of individual- and multiple-drug-resistant bacteria were detected, although sampling events were not correlated with clinical outbreaks and drug therapy.     

Multiresistant waterborne pathogens isolated from water reservoirs and cooling systems

Aims:  To determine the incidence of multiple antibiotic-resistant strains of the emergent human pathogens Legionella pneumophila , Pseudomonas aeruginosa and mesophilic Aeromonas species among those isolated from water reservoirs and industrial cooling systems.
Methods and Results:  Water from four natural water reservoirs and four industrial cooling towers was sampled for 1 year period. The total heterotrophs, mesophilic Aeromonas , Pseudomonas spp. and Legionella spp. counts were performed as recommended by standard procedures, and the sensitivity of the isolates to 27 antibiotics was tested. A total of 117 Aeromonas , 60 P. aeruginosa and 15  L. pneumophila strains were isolated and identified by means of biochemical tests and DNA probes. 46·4% of Aeromonas , and 100% of P. aeruginosa isolates presented multiple resistance. Legionella pneumophila strains were generally sensitive to the drugs used.
Conclusions:  Antibiotic-resistant pathogenic bacteria belonging to P. aeruginosa and mesophilic Aeromonas species are common in natural aquatic environments. Thus, the risk of waterborne diseases owing to domestic and industrial uses of freshwater should be re-examined from the increase of bacterial resistance point of view.
Significance and Impact of the Study:  These data confirm the emergence of bacteria resistant to antibiotics in aquatic environments.     

Accumulation of Polyphosphate in Lactobacillus spp. and Its Involvement in Stress Resistance

Polyphosphate (poly-P) is a polymer of phosphate residues synthesized and in some cases accumulated by microorganisms, where it plays crucial physiological roles such as the participation in the response to nutritional stringencies and environmental stresses. Poly-P metabolism has received little attention in Lactobacillus, a genus of lactic acid bacteria of relevance for food production and health of humans and animals. We show that among 34 strains of Lactobacillus, 18 of them accumulated intracellular poly-P granules, as revealed by specific staining and electron microscopy. Poly-P accumulation was generally dependent on the presence of elevated phosphate concentrations in the culture medium, and it correlated with the presence of polyphosphate kinase (ppk) genes in the genomes. The ppk gene from Lactobacillus displayed a genetic arrangement in which it was flanked by two genes encoding exopolyphosphatases of the Ppx-GppA family. The ppk functionality was corroborated by its disruption (LCABL_27820 gene) in Lactobacillus casei BL23 strain. The constructed ppk mutant showed a lack of intracellular poly-P granules and a drastic reduction in poly-P synthesis. Resistance to several stresses was tested in the ppk-disrupted strain, showing that it presented a diminished growth under high-salt or low-pH conditions and an increased sensitivity to oxidative stress. These results show that poly-P accumulation is a characteristic of some strains of lactobacilli and may thus play important roles in the physiology of these microorganisms.     

Sustained swimming improves muscle growth and cellularity in gilthead sea bream

Two groups of juvenile gilthead sea bream were kept on two different swimming regimes (Exercise, E: 1.5 body length s⁻¹ or Control, C: voluntary activity) for 1 month. All fish were first adapted to an experimental diet low in protein and rich in digestible carbohydrates (37.2% protein, 40.4% carbohydrates, 12.5% lipid). The cellularity and capillarisation of white muscle from two selected areas (cranial (Cr), below the dorsal fin, and caudal (Ca), behind the anal fin) were compared. The body weight and specific growth rate (SGR) of group E rose significantly without an increment in feed intake, pointing to higher nutrient-use efficiency. The white muscle fibre cross-sectional area and the perimeter of cranial samples increased after sustained activity, evidencing that sustained exercise enhances hypertrophic muscle development. However, we cannot conclude or rule out the possibility of fibre recruitment because the experimental period was too short. In the control group, capillarisation, which is extremely low in gilthead sea bream white muscle, showed a significantly higher number of fibres with no surrounding capillaries (F0) in the cranial area than in the caudal area, unlike the exercise group. Sustained swimming improved muscle machinery even in tissue normally associated with short bouts of very rapid anaerobic activity. So, through its effect on the use of tissue reserves and nutrients, exercise contributes to improvements in fish growth what can contribute to reducing nitrogen losses.