Effects of beneficial bacteria on biomass,photosynthetic parameters and cell composition of the microalga Muriellopsis sp. adapted to grow in seawater

The present study evaluated the effects of five bacterial isolates from the microalga Muriellopsis sp. on the microalgal biomass concentration (g/L), specific growth rate (K), photosynthetic quantum yield (QY), non‐photochemical quenching (NPQ), maximum relative electron transport rates (rETR max) and levels of nutritional components such as carbohydrates, lipids, proteins and carotenoids in Muriellopsis sp. cultivated in seawater under indoor and outdoor conditions. The bacterial strains were Microbacterium sp. Dom 1; Pseudomonas sp. Dom2; Microbacterium sp. Dom 3; Rhizobium sp. Dom 4; and Dietzia sp. Dom 5, as well as the Pseudoalteromonas sp. (SLP1), a bacterium known to promote the growth of microalgae. At the laboratory level, inoculation of the strains SLP1, Dom 1, Dom 3 and Dom 5 resulted in higher specific growth rates and biomass of the microalga. Subsequently, the best results were obtained with a combination of the selected bacterial strains (Dom1, Dom 3, Dom5 and SLP1) under outdoor culture conditions improved the biomass, proteins, carbohydrates and total carotenoids in 22.12%, 48.28%, 19,25% and 48.27%, respectively, compared to cultures without the incorporation of the selected bacteria (control), while no effects were observed on the photosynthetic parameters. Thus, it was demonstrated that positive associations of the selected bacterial strains played an important role in the production of Muriellopsis sp. acclimatized to grow in seawater. This is of crucial importance, especially in desert areas, where solar radiation is high and freshwater is a limited resource.     

Rainbow trout (Oncorhynchus mykiss,Walbaum ) develop a more robust body shape under organic rearing

Prolonged exposure to captive conditions has led to the development of a rainbow trout ‘farmed’ phenotype, which is different from that of wild trout. Selection for desirable productive traits in hatcheries has resulted in the development of some morphological traits that are maladaptive in nature. The recent development of organic aquaculture, guided by the well‐being of the fish, could potentially produce a new farmed phenotype that would be more adaptive in nature. In this study, rainbow trout reared in intensive and organic farms were compared by means of shape analysis, to detect patterns of shape variation associated with rearing environment. The results of this study highlight a significant effect of the rearing method on rainbow trout shape: organically reared trout showed a higher body profile, in particular in the head and trunk regions, shorter median fins and a deeper caudal peduncle. A combined effect of density and habitat complexity could have contributed to the observed shape differences: in organic rearing systems, lower densities and steady water could increase territoriality and aggressive interactions, promoting body designs more functional in rapid attacks and escapes.     

Occupancy pattern of a long-horned beetle in a variegated forest landscape: linkages between tree quality and forest cover across spatial scales

Context

Interactions between landscape-scale processes and fine-grained habitat heterogeneity are usually invoked to explain species occupancy in fragmented landscapes. In variegated landscapes, however, organisms face continuous variation in micro-habitat features, which makes necessary to consider ecologically meaningful estimates of habitat quality at different spatial scales.

Objectives

We evaluated the spatial scales at which forest cover and tree quality make the greatest contribution to the occupancy of the long-horned beetle Microplophorus magellanicus (Coleoptera: Cerambycidae) in a variegated forest landscape.

Methods

We used averaged data of tree quality (as derived from remote sensing estimates of the decay stage of single trees) and spatially independent pheromone-baited traps to model the occurrence probability as a function of multiple cross-scale combinations between forest cover and tree quality (with scales ranging between 50 and 400 m).

Results

Model support and performance increased monotonically with the increasing scale at which tree quality was measured. Forest cover was not significant, and did not exhibit scale-specific effects on the occurrence probability of M. magellanicus. The interactive effect between tree quality and forest cover was stronger than the independent (additive) effects of tree quality and particularly forest cover. Significant interactions included tree quality measured at spatial scales ≥200 m, but cross-scale interactions occurred only in four of the seven best-supported models.

Conclusions

M. magellanicus respond to the high-quality trees available in the landscape rather than to the amount of forest per se. Conservation of viable metapopulations of M. magellanicus should consider the quality of trees at spatial scales >200 m.

     

Effect of 1-24ACTH administration on sheep blood granulocyte functions

The objective of the present study was to determine the efficiency of blood neutrophils (PMN) taken from sheep during acute stress. Ten healthy Charolle sheep were sampled before treatment (T0) and 1 (T1), 2 (T2), 24 (T24) and 48 (T48) hours after 1-24ACTH administration. Ten sheep serving as the controls were sampled at the same time intervals, using saline solution instead of 1-24ACTH. At each time sampling, rectal temperature, heart rate, cortisol, glucose, non-esterified fatty acids (NEFA), total and differential leukocyte counts were evaluated. PMN were isolated after centrifugation of whole blood and hypotonic lysis of RBC. Chemotaxis was evaluated on a modified Boyden chamber using a nitrate cellulose filter and both Zymosan activated serum (ZAS) and interleukin-8 (IL-8) as chemoattractants. Phagocytosis was measured using both non-opsonized latex beads and fluoresceinated yeasts opsonized with homologous serum. Superoxide (O(-)2) production was evaluated by measuring superoxide dismutase-inhibitable reduction of ferricytochrome C, and adherence by a colorimetric assay of acid phosphatase activity of adherent cells. The administration of 1-24ACTH induced an acute stress reaction, indicated by the presence of clinical, biochemical and hematological changes. Adherence significantly increased from T0 to T2 in treated sheep. This might be responsible for the depression of non-specific immunity in stressed animals. Studies using stressors other than 1-24 ACTH are needed to verify the influence of other components of the stress reaction on PMN functions.     

Extra hepatic expression of the acute phase protein alpha 1-acid glycoprotein in normal bovine tissues

Combined quantitative (real-time) polymerase chain reaction and immunohistochemistry were used to evaluate the expression of the minor acute phase protein alpha 1-acid glycoprotein (AGP, orosomucoid) in bovine extrahepatic tissues. AGP was produced mainly in the salivary glands and spleen, whereas minor expression was detected in all other tissues sampled, including lung, lymph nodes, uterus, ovary, kidney and tongue. The findings were consistent with immunohistochemical results. In view of the immunomodulatory and direct antibacterial activity of AGP, its expression in the salivary glands may signal an involvement in the regulation of the local immunity, even in non-pathological conditions.     

Genetic immunization with the immunodominant antigen P48 of Mycoplasma agalactiae stimulates a mixed adaptive immune response in BALBc mice

A DNA vaccine against contagious agalactia was developed for the first time, encoding the P48 of Mycoplasma agalactiae. Specific immune responses elicited in BALB/c mice were evaluated. Both total IgG and IgG1 were detected in mice vaccinated with pVAX1/P48. Proliferation of mononuclear cells of the spleen, levels of gamma interferon, interleukin-12, and interleukin-2 mRNAs were enhanced in immunized animals. Results indicate that pVAX1/P48 vaccination induced both T_h1 and T_h2 immune responses. Nucleic acid immunization could be a new strategy against M. agalactiae infections and may be potentially used to develop vaccines for other Mycoplasma diseases.     

Antioxidant systems and lymphocyte proliferation in the horse,sheep and dog

To better define the species-specific antioxidant systems and to ascertain the influence of the intracellular redox status on the immune system of different animal species, we determined lymphocyte glutathione peroxidase (GSHPx) activity, plasmatic glutathione levels (GSH) and the effect of H2O2 on the responsiveness of lymphocytes to proliferative stimuli. Among the three species considered, sheep presented the lowest plasmatic GSH and the highest lymphocyte GSHPx activity. On the contrary, dogs showed an inverted pattern (high GSH - low GSHPx). Horses displayed intermediate values for both parameters analysed. The effect of H2O2 on the proliferative capacity of lymphocytes was the same for all three species; the 200 microM dose in particular was strongly inhibiting. Each species, however, showed different rates of inhibition: sheep exhibited the highest sensitivity to the antiproliferative effect of H2O2. Our results confirmed that high H2O2 concentrations (200 microM) are noxious for the cellular functions of all animals; however this effect is mediated by a rigorously species-specific relationship between the intracellular reactive oxygen species (ROS) and the molecular systems involved in cell proliferation.     

Studies on umami taste. Synthesis of new guanosine 5'-phosphate derivatives and their synergistic effect with monosodium glutamate

A number of N2-alkyl and N2-acyl derivatives of guanosine 5'-phosphate (GMP) have been synthesized and tested for their synergistic effect with monosodium L-glutamate (MSG), the prototypical substance imparting umami taste to savory-based foods. Capacities to enhance the taste intensity of MSG (gamma values) were estimated through subjective comparisons of MSG/nucleotide mixtures in water with appropriate solutions of MSG alone. Assuming beta = gamma[nucleotide]/gamma[IMP], beta values of the N2-substituted GMPs were found in the range 1.2-5.7. Such values appear to be related to the chain length of the substituent in the 2-position of the purine nucleus and dependent on the replacement of a CH 2 group with an S atom and/or with an alpha-CO group. These findings indicate that the exocyclic NHR group of the guanine moiety is actively implicated in the synergism between GMP derivatives and MSG. Theoretical calculations suggest that an anti conformation is probably assumed by ribonucleotide molecules interacting with umami receptors.     

Chemical composition and antimicrobial activity of Momordica charantia seed essential oil

The essential oil obtained from the seeds of Momordica charantia was analyzed by GC/MS. Twenty-five components, representing 90.9% of the oil, were identified. The main constituents were trans-nerolidol, apiole, cis-dihydrocarveol and germacrene D. Furthermore, the oil was tested for its antibacterial and antifungal activities. Staphylococcus aureus was found to be the most sensitive microorganism with MIC values <500 microg/ml.