Antimicrobial and biological effects of ipemphos and amphos on bacterial and yeast strains

In this study, the antimicrobial effects of monophosphazenes such as SM ipemphos and amphos were examined on bacterial and yeast strains. In addition, the biological effects of these compounds were tested on the lipid level of Saccharomyces cerevisiae and Candida albicans cells. The SM has an antimicrobial effect on the bacterial and yeast strains within the range of 100 and 1500 microg. When the concentration was increased, the inhibition zone expanded on the growth media ( p < 0.01; p < 0.001). The ipemphos did not affect the bacterial and yeast cells in the 100 and 600 microg range. In addition, the amphos did not show an antimicrobial effect on the bacterial cells between 100 and 300 microg or on yeast cells at any of the administered concentrations. In vitro media, the biological effects of these molecules were compared with vitamin E, melatonin and fish oil on the yeast cells. We have found that monophosphazenes have growth effects on the cells in vitro media. The lipid level of S. cerevisiae cells was decreased by 300 microg doses of vitamin E, fish oil, and ipemphos (respectively; p < 0.05, p < 0.01, and p < 0. 001). In addition, the lipid levels of the same yeast cells were depressed by 1000-microg doses in all supplemented groups. However, it was observed that the highest decrease in lipid level of S. cerevisiae cells occurred in the amphos group ( p < 0.001). The lipid levels of the C. albicans cells were significantly reduced ( p < 0.01) by 300 microg of amphos and melatonin. In contrast, the vitamin E and fish oil significantly raised ( p < 0.01; p < 0.001) the lipid level of the same yeast cell, as compared with the control. In addition, the lipid level of these cells was increased by administration of 1000 microg vitamin E, and melatonin ( p < 0.01). In conclusion, while high concentrations of ipemphos and amphos have an antimicrobial effect on bacterial and yeast cells, amphos did not affect the yeast cells. While ipemphos and amphos increased cell growth in media, they reduced the lipid level of C. albicans and S. cerevisiae. In addition, the antioxidants such as vitamin E, melatonin, and fish oils affected the lipid level of yeast cells.     

Quantitative methanol-burning lung model for validating gas-exchange measurements over wide ranges of FIO2

Themethanol-burning lung model has been used as a technique for generatinga predictable ratio of carbon dioxide production (CO₂) to oxygen consumption(O₂) or respiratoryquotient (RQ). Although an accurate RQ can be generated, quantitativelypredictable and adjustableO₂ andCO₂ cannot be generated. Wedescribe a new burner device in which the combustion rate of methanolis always equal to the infusion rate of fuel over an extended range ofO₂ concentrations. This permitsthe assembly of a methanol-burning lung model that is usable withO₂ concentrations up to 100% and provides continuously adjustable and quantitativeO₂ (69-1,525 ml/min)and CO₂ (46-1,016ml/min) at a RQ of 0.667.

     

Heterologous Aggregates Promote De Novo Prion Appearance via More than One Mechanism

Prions are self-perpetuating conformational variants of particular proteins. In yeast, prions cause heritable phenotypic traits. Most known yeast prions contain a glutamine (Q)/asparagine (N)-rich region in their prion domains. [PSI⁺], the prion form of Sup35, appears de novo at dramatically enhanced rates following transient overproduction of Sup35 in the presence of [PIN⁺], the prion form of Rnq1. Here, we establish the temporal de novo appearance of Sup35 aggregates during such overexpression in relation to other cellular proteins. Fluorescently-labeled Sup35 initially forms one or a few dots when overexpressed in [PIN⁺] cells. One of the dots is perivacuolar, colocalizes with the aggregated Rnq1 dot and grows into peripheral rings/lines, some of which also colocalize with Rnq1. Sup35 dots that are not near the vacuole do not always colocalize with Rnq1 and disappear by the time rings start to grow. Bimolecular fluorescence complementation failed to detect any interaction between Sup35-VN and Rnq1-VC in [PSI ⁺][PIN ⁺] cells. In contrast, all Sup35 aggregates, whether newly induced or in established [PSI ⁺], completely colocalize with the molecular chaperones Hsp104, Sis1, Ssa1 and eukaryotic release factor Sup45. In the absence of [PIN⁺], overexpressed aggregating proteins such as the Q/N-rich Pin4C or the non-Q/N-rich Mod5 can also promote the de novo appearance of [PSI ⁺]. Similar to Rnq1, overexpressed Pin4C transiently colocalizes with newly appearing Sup35 aggregates. However, no interaction was detected between Mod5 and Sup35 during [PSI⁺] induction in the absence of [PIN ⁺]. While the colocalization of Sup35 and aggregates of Rnq1 or Pin4C are consistent with the model that the heterologous aggregates cross-seed the de novo appearance of [PSI ⁺], the lack of interaction between Mod5 and Sup35 leaves open the possibility of other mechanisms. We also show that Hsp104 is required in the de novo appearance of [PSI⁺] aggregates in a [PIN ⁺]-independent pathway.     

Antifungal activity of essential oils against three vegetative-compatibility groups of <Emphasis Type="Italic">Verticillium dahliae</Emphasis>

The antifungal activities of volatile phase effects of essential oils from Origanum onites, O. syriacum, O. minutiflorum, O. vulgare, O, marjorana, Thymus vulgaris, T. serpyllum, Rosmarinus officinalis, Salvia officinalis and Micromeria fruticosa were evaluated for their ability to inhibit growth of three vegetative compatibility groups (VCGs) of Verticillium dahliae. Carvacrol was the main component of O. onites, O. minutiflorum and O. vulgare essential oils, while γ-terpinene was the main component of O. syriacum. P-cymene and thymol were the dominant component of T. vulgaris and T. serpyllum. β- thujone and l-camphor were the main component of S. officinalis. Polegone and isomenthone were the dominant components of M. fruticosa essential oil. Based on the in vitro test, the degree of fungistatical effects can be ranked in the following order of inhibition: O. syriacum = O. onites = O. minutiflorum = O. vulgare = T. vulgaris > T. serpyllum > M. fruticosa > S. officinalis = O. marjorana > R. officinalis. The essential oils of S. officinalis, O. marjorana and R. officinalis displayed moderate antifungal activity, that increased with increasing concentrations. Among the VCGs, VCG2A and VCG4B were found to be highly sensitive to the essential oils. The essential oils of O. syriacum, O. onites, O. minutiflorum, O. vulgare and T. vulgaris were the most efficacious, demonstrating strong antifungal activity against all of the tested VCGs of V. dahliae at relatively low concentrations and they could find practical application as natural fungicides in the prevention and protection of plants from V. dahliae infections.     

Reversible immobilization of Candida rugosa lipase on fibrous polymer grafted and sulfonated p(HEMA/EGDMA) beads

Poly(2-hydroxyethyl methacrylate/ethylenglycol dimethacrylate) beads were grafted with poly(glycidylmethacrylate) via surface initiated atom transfer radical polymerization. Epoxy groups of the grafted polymer were modified in to sulfone groups. Sulfonated beads were characterized by swelling studies, FT-IR, SEM and elemental analysis, and were used for reversible immobilization of lipase. Under given experimental conditions, the beads had an adsorption capacity of 44.7 mg protein/g beads. The adsorbed lipase on beads retained up to 67.4% of its initial activity. The immobilized lipase exhibited improved thermal and storage stabilities over those of the free enzyme. The immobilized lipase could desorb 1.0 M NaCl solution at pH 8.0, and the sulfonated beads can be repeatedly charged with fresh enzyme after inactivation upon use.     

Genetic Structure of Brown Trout (Salmo trutta) Populations from Turkey Based on Microsatellite Data

This present study investigated micro- and macro-geographic microsatellite DNA variations using five polymorphic microsatellite loci from 27 brown trout populations in Turkey. Average number of alleles and average observed heterozygosity were 7.4 and 0.254, respectively. Even populations from the same sea basin and river system (the so called micro-geographic regions) had unique alleles. Genetic variation among the populations from macro-geographic regions (different sea basins and river systems) was 45.78%. The mtDNA lineages of brown trout that have previously been identified by mtDNA analyses were supported by the analysis of the microsatellite DNA data in general. The Çatak population, which belongs to the Tigris lineage, was clustered together with the Euphrates populations within the Adriatic mtDNA lineage, based on microsatellite data. Both mitochondrial and microsatellite DNA analyses have made it possible to determine a secondary contact between Adriatic and Tigris lineages.     

Sugar transport systems of Bifidobacterium longum NCC2705

Here we present the complement of the carbohydrate uptake systems of the strictly anaerobic probiotic Bifidobacterium longum NCC2705. The genome analysis of this bacterium predicts that it has 19 permeases for the uptake of diverse carbohydrates. The majority belongs to the ATP-binding cassette transporter family with 13 systems identified. Among them are permeases for lactose, maltose, raffinose, and fructooligosaccharides, a commonly used prebiotic additive. We found genes that encode a complete phosphotransferase system (PTS) and genes for three permeases of the major facilitator superfamily. These systems could serve for the import of glucose, galactose, lactose, and sucrose. Growth analysis of NCC2705 cells combined with biochemical characterization and microarray data showed that the predicted substrates are consumed and that the corresponding transport and catabolic genes are expressed. Biochemical analysis of the PTS, in which proteins are central in regulation of carbon metabolism in many bacteria, revealed that B. longum has a glucose-specific PTS, while two other species (Bifidobacterium lactis and Bifidobacterium bifidum) have a fructose-6-phosphate-forming fructose-PTS instead. It became obvious that most carbohydrate systems are closely related to those from other actinomycetes, with a few exceptions. We hope that this report on B. longum carbohydrate transporter systems will serve as a guide for further in-depth analyses on the nutritional lifestyle of this beneficial bacterium.