Effect of Organic Selenium Supplementation on Growth, Se Uptake, and Nutrient Utilization in Guinea Pigs

Forty weaned male guinea pigs (Cavia porcellus) of 152.6?±?7.96 g mean body weight were divided into four equal groups and fed a common basal diet comprised of 25% ground cowpea (Vigna unguiculata) hay, 30% ground maize (Zea mays) grain, 22% ground gram (Cicer arietinum) grain, 9.5% deoiled rice (Oryza sativa) bran, 6% soybean (Glycine max) meal, 6% fish meal, 1.5% mineral mixture (without Se), and ascorbic acid at 200 mg/kg to meet their nutrient requirements along with 0, 0.1, 0.2, and 0.3 ppm of organic selenium (Se) in groups I, II, III, and IV, respectively. Experimental feeding lasted for a period of 10 weeks, during which, daily feed intake and weekly body weights were recorded. Intake and digestibility of dry matter, organic matter, ether extract, crude fiber, and nitrogen-free extract as well as uptake of calcium and phosphorus were similar (P?>?0.05) among the four groups. Feed:gain ratio was also similar (P?>?0.05) in the four groups. However, digestibility of crude protein was significantly (P?<?0.001) higher in group II supplemented with 0.1 ppm organic Se as compared to other three group. Intake and absorption of Se was significantly (P?<?0.001) higher in all the Se supplemented groups as compared to control group. Average daily gain (ADG) was significantly (P?<?0.05) higher in group II (3.16 g/day) and III (3.38 g/day) as compared to group I (2.88 g/day). However, ADG in group IV (supplemented 0.3 ppm organic Se) was significantly (P?<?0.05) lower (2.83 g/day) than group II and III, but comparable (P?>?0.05) to group I. Findings of the present experiment suggests that Se requirements of guinea pigs are ≥0.2 ppm, as supplementation of 0.1 ppm organic Se in the diet (having 0.1 ppm Se) not only enhanced their growth rate but also improved the protein utilization.     

Rediscovering cyanobacteria as valuable sources of bioactive compounds (Review)

Cyanobacteria are a simple, but primitive and diverse group of microorganisms, with characteristics in common to both bacteria and algae. Their success as a group in a wide range of habitats has been attributed to their unique physiological characters and high adaptive ability under a wide range of environmental conditions. The potential of cyanobacteria as a source of a variety of compounds such as polysaccharides, lipids, proteins, vitamins, sterols, enzymes, pharmaceuticals and other fine chemicals is well recognized, and their demand is now on an increasing trend. This compilation reviews the salient advances in the discovery of bioactive compounds from cyanobacteria and their significance in agriculture and industry.     

Toxicity of unsaturated fatty acids to the biohydrogenating ruminal bacterium, <Emphasis Type="Italic">Butyrivibrio fibrisolvens</Emphasis>

Background  

Health-promoting polyunsaturated fatty acids (PUFA) are abundant in forages grazed by ruminants and in vegetable and fish oils used as dietary supplements, but only a small proportion of PUFA finds its way into meat and milk, because of biohydrogenation in the rumen. Butyrivibrio fibrisolvens plays a major role in this activity. The aim of this study was to investigate the mechanisms by which PUFA affect the growth of B. fibrisolvens, how PUFA are metabolized and the metabolic response to growth in the presence of PUFA.     

Healthy Human T-Cell Responses to Aspergillus fumigatus Antigens

Background

Aspergillus fumigatus is associated with both invasive and allergic pulmonary diseases, in different hosts. The organism is inhaled as a spore, which, if not cleared from the airway, germinates into hyphal morphotypes that are responsible for tissue invasion and resultant inflammation. Hyphae secrete multiple products that function as antigens, evoking both a protective (T_H1–T_H17) and destructive allergic (T_H2) immunity. How Aspergillus allergens (Asp f proteins) participate in the development of allergic sensitization is unknown.

Methodology/Principal Findings

To determine whether Asp f proteins are strictly associated with T_H2 responses, or represent soluble hyphal products recognized by healthy hosts, human T cell responses to crude and recombinant products were characterized by ELISPOT. While responses (number of spots producing IFN-γ, IL-4 or IL-17) to crude hyphal antigen preparations were weak, responses to recombinant Asp f proteins were higher. Recombinant allergens stimulated cells to produce IFN-γ more so than IL-4 or IL-17. Volunteers exhibited a diverse CD4+ and CD8+ T cell antigen recognition profile, with prominent CD4 T_H1-responses to Asp f3 (a putative peroxismal membrane protein), Asp f9/16 (cell wall glucanase), Asp f11 (cyclophilin type peptidyl-prolyl isomerase) and Asp f22 (enolase). Strong IFN-γ responses were reproduced in most subjects tested over 6 month intervals.

Conclusions

Products secreted after conidial germination into hyphae are differentially recognized by protective T cells in healthy, non-atopic individuals. Defining the specificity of the human T cell repertoire, and identifying factors that govern early responses may allow for development of novel diagnostics and therapeutics for both invasive and allergic Aspergillus diseases.     

Neisseria meningitidis PorB, a TLR2 ligand, induces an antigen-specific eosinophil recall response: potential adjuvant for helminth vaccines?

Efficacious adjuvants are important components of new vaccines. The neisserial outer membrane protein, PorB, is a TLR2 ligand with unique adjuvant activity. We demonstrate that PorB promotes Th2-skewed cellular immune response to the model Ag, OVA, in mice, including Ag-specific recall eosinophil recruitment to the peritoneum. PorB induces chemokine secretion by myeloid cells using both TLR2-dependent and -independent mechanisms, suggesting that anatomical distribution of TLR2(+) cells may not be a limiting factor for potential vaccine strategies. The results from this study suggest that PorB, and other TLR2 ligands, may be ideal for use against pathogens where eosinophilia may be protective, such as parasitic helminths.     

Rho/Rho-associated kinase-II signaling mediates disassembly of epithelial apical junctions

Apical junctional complex (AJC) plays a vital role in regulation of epithelial barrier function. Disassembly of the AJC is observed in diverse physiological and pathological states; however, mechanisms governing this process are not well understood. We previously reported that the AJC disassembly is driven by the formation of apical contractile acto-myosin rings. In the present study, we analyzed the signaling pathways regulating acto-myosin-dependent disruption of AJC by using a model of extracellular calcium depletion. Pharmacological inhibition analysis revealed a critical role of Rho-associated kinase (ROCK) in AJC disassembly in calcium-depleted epithelial cells. Furthermore, small interfering RNA (siRNA)-mediated knockdown of ROCK-II, but not ROCK-I, attenuated the disruption of the AJC. Interestingly, AJC disassembly was not dependent on myosin light chain kinase and myosin phosphatase. Calcium depletion resulted in activation of Rho GTPase and transient colocalization of Rho with internalized AJC proteins. Pharmacological inhibition of Rho prevented AJC disassembly. Additionally, Rho guanine nucleotide exchange factor (GEF)-H1 translocated to contractile F-actin rings after calcium depletion, and siRNA-mediated depletion of GEF-H1 inhibited AJC disassembly. Thus, our findings demonstrate a central role of the GEF-H1/Rho/ROCK-II signaling pathway in the disassembly of AJC in epithelial cells.     

Improved production of biosurfactant by a <Emphasis Type="Italic">Pseudomonas aeruginosa</Emphasis> mutant using vegetable oil refinery wastes

Biosurfactant production by Pseudomonas aeruginosa EBN-8 mutant was studied in shake flasks on separate wastes from canola, soybean and corn oil refineries. Of the substrates tested, canola oil refinery waste (COD=20 g l⁻¹) supplemented with sodium nitrate (at COD/N=20) showed the best microbial growth (4.50 g l⁻¹) and rhamnolipid production (8.50 g l⁻¹), at 10 d of incubation with the specific growth rate of 0.316 h⁻¹ and specific product yield of 0.597 g g⁻¹ h. Its cell-free supernatant showed the critical micelle dilution (CMD) of 150 and surface tension (ST) of 28.5 mN m⁻¹.     

Genome mining revealed polyhydroxybutyrate biosynthesis by Ramlibacter agri sp. nov., isolated from agriculture soil in Korea

A white-colony-forming, facultative anaerobic, motile and Gram-stain-negative bacterium, designated G-1-2-2 ^T was isolated from soil of agriculture field near Kyonggi University, Republic of Korea. Strain G-1-2-2 ^T synthesized the polyhydroxybutyrate and could grow at 10–35 °C. The phylogenetic analysis based on 16S rRNA gene sequence showed that, strain G-1-2-2 ^T formed a lineage within the family Comamonadaceae and clustered as a member of the genus Ramlibacter. The 16S rRNA gene sequence of strain G-1-2-2 ^T showed high sequence similarities with Ramlibacter ginsenosidimutans BXN5-27 ^T (97.9%), Ramlibacter monticola G-3-2 ^T (97.9%) and Ramlibacter alkalitolerans CJ661^T (97.5%). The sole respiratory quinone was ubiquinone-8 (Q-8). The major polar lipids were phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol, and an unidentified phospholipid. The principal cellular fatty acids were C_16:0, cyclo-C_17:0, summed feature 3 (C_16:1ω7c and/or C_16:1ω6c) and summed feature 8 (C_18:1ω7c and/or C_18:1ω6c). The genome of strain G-1-2-2 ^T was 7,200,642 bp long with 13 contigs, 6,647 protein-coding genes, and DNA G?+?C content of 68.9%. The average nucleotide identity and in silico DNA–DNA hybridization values between strain G-1-2-2 ^T and close members were?≤?81.2 and 24.1%, respectively. The genome of strain G-1-2-2 ^T showed eight putative biosynthetic gene clusters responsible for various secondary metabolites. Genome mining revealed the presence of atoB, atoB2, phaS, phbB, phbC, and bhbD genes in the genome which are responsible for polyhydroxybutyrate biosynthesis. Based on these data, strain G-1-2-2 ^T represents a novel species in the genus Ramlibacter, for which the name Ramlibacter agri sp. nov. is proposed. The type strain is G-1-2-2 ^T (=?KACC 21616 ^T?=?NBRC 114389 ^T).