Funkcionalne osobine sojeva bakterija mlečne kiseline i mikrokoka u sredini sličnoj mesnoj masi sirovih kobasica kao modelu

In this study we investigated the potential probiotic properties of Lactobacillus plantarum L 24 - 2, Lactococcus lactis biovar diacetylactis N 237 and strain Micrococcus sp. It has been found that microbial species exhibited the ability to survive under conditions of high concentrations of bile salts (2.0%) and low pH (2.0). This ability varies for different types, but they will remain until the end of experiments zivotosposobne. This, together with the antimicrobial activity projavljenoj them makes them suitable for the new composition uklucivane the starter culture, which can be effectively used as an antimicrobial barrier to the development of pathogenic bacteria in the manufacture of a crude - product of dried meat.U ovom radu su ispitivana potencijalna probiotska svojstva bakterija Lactobacillus Plantarum soj L 24 - 2, Lactococcus lactis biovar diacetilactis soj N 237 i Micrococcus sp. Utvrđeno je da mikrobne vrste pokazuju sposobnost za preživljavanje pod uslovima visoke koncentracije žučnih soli (2,0%) i niskog pH (2.0). Ova sposobnost varira kod različitih ispitivanih bakterija, ali sve one ostaju životno sposobne do kraja eksperimenata. Ovo, zajedno sa dokazanom antimikrobnom aktivnošću čini ih pogodnim za uključivane u sastav novih starter kultura, koje mogu efikasno poslužiti kao antimikrobna barijera za razvoj patogenih bakterija u proizvodnji sirovih - sušenih proizvoda od mesa

A Glutathione Peroxidase, Intracellular Peptidases and the TOR Complexes Regulate Peptide Transporter PEPT-1 in C. elegans

The intestinal peptide transporter PEPT-1 in Caenorhabditis elegans is a rheogenic H+-dependent carrier responsible for the absorption of di- and tripeptides. Transporter-deficient pept-1(lg601) worms are characterized by impairments in growth, development and reproduction and develop a severe obesity like phenotype. The transport function of PEPT-1 as well as the influx of free fatty acids was shown to be dependent on the membrane potential and on the intracellular pH homeostasis, both of which are regulated by the sodium-proton exchanger NHX-2. Since many membrane proteins commonly function as complexes, there could be proteins that possibly modulate PEPT-1 expression and function. A systematic RNAi screening of 162 genes that are exclusively expressed in the intestine combined with a functional transport assay revealed four genes with homologues existing in mammals as predicted PEPT-1 modulators. While silencing of a glutathione peroxidase surprisingly caused an increase in PEPT-1 transport function, silencing of the ER to Golgi cargo transport protein and of two cytosolic peptidases reduced PEPT-1 transport activity and this even corresponded with lower PEPT-1 protein levels. These modifications of PEPT-1 function by gene silencing of homologous genes were also found to be conserved in the human epithelial cell line Caco-2/TC7 cells. Peptidase inhibition, amino acid supplementation and RNAi silencing of targets of rapamycin (TOR) components in C. elegans supports evidence that intracellular peptide hydrolysis and amino acid concentration are a part of a sensing system that controls PEPT-1 expression and function and that involves the TOR complexes TORC1 and TORC2

Relaxation of Selective Constraints Causes Independent Selenoprotein Extinction in Insect Genomes

BACKGROUND: Selenoproteins are a diverse family of proteins notable for the presence of the 21st amino acid, selenocysteine. Until very recently, all metazoan genomes investigated encoded selenoproteins, and these proteins had therefore been believed to be essential for animal life. Challenging this assumption, recent comparative analyses of insect genomes have revealed that some insect genomes appear to have lost selenoprotein genes. METHODOLOGY/PRINCIPAL FINDINGS: In this paper we investigate in detail the fate of selenoproteins, and that of selenoprotein factors, in all available arthropod genomes. We use a variety of in silico comparative genomics approaches to look for known selenoprotein genes and factors involved in selenoprotein biosynthesis. We have found that five insect species have completely lost the ability to encode selenoproteins and that selenoprotein loss in these species, although so far confined to the Endopterygota infraclass, cannot be attributed to a single evolutionary event, but rather to multiple, independent events. Loss of selenoproteins and selenoprotein factors is usually coupled to the deletion of the entire no-longer functional genomic region, rather than to sequence degradation and consequent pseudogenisation. Such dynamics of gene extinction are consistent with the high rate of genome rearrangements observed in Drosophila. We have also found that, while many selenoprotein factors are concomitantly lost with the selenoproteins, others are present and conserved in all investigated genomes, irrespective of whether they code for selenoproteins or not, suggesting that they are involved in additional, non-selenoprotein related functions. CONCLUSIONS/SIGNIFICANCE: Selenoproteins have been independently lost in several insect species, possibly as a consequence of the relaxation in insects of the selective constraints acting across metazoans to maintain selenoproteins. The dispensability of selenoproteins in insects may be related to the fundamental differences in antioxidant defense between these animals and other metazoans.The work described here is funded by grants from the Spanish Ministery of Education and Science and from the BioSapiens European Network of Excellence to RG. CEC is reciepient of a pre-doctoral fellowship from the Spanish Ministery of Education and Science

Experimental and numerical investigations on the Mustafa Pasha Mosque large scale model

The experimental and analytical results presented in this paper are a part of the activities performed within the Sixth Framework Program PROHITECH - "Earthquake protection of historical buildings by reversible mixed technologies". For the selected prototype structure - historical monument Mustafa Pasha Mosque in Skopje, 1/6-scale model was constructed and tested on seismic shaking table in several phases. The main aim of experimental model testing was to investigate the seismic stability of the monument after applying a reversible technology for strengthening. Beside the experimental shaking table testing of the model, three-dimensional finite element analyses were carried out using the general purpose software package ANSYS. The main aim of the numerical simulations was to predict the response of the large scale model during the shaking table tests. The results of finite element analysis have been compared with the experimental outcome, discussing the differences between the predicted seismic capacity and the experimental one for each phase of the test program. The evolution of partial and global collapse mechanisms observed during the tests has been also analyzed on the basis of numerical results

Selenoprotein TRXR-1 and GSR-1 are essential for removal of old cuticle during molting in Caenorhabditis elegans

Selenoproteins, in particular thioredoxin reductase, have been implicated in countering oxidative damage occurring during aging but the molecular functions of these proteins have not been extensively investigated in different animal models. Here we demonstrate that TRXR-1 thioredoxin reductase, the sole selenoprotein in Caenorhabditis elegans, does not protect against acute oxidative stress but functions instead together with GSR-1 glutathione reductase to promote the removal of old cuticle during molting. We show that the oxidation state of disulfide groups in the cuticle is tightly regulated during the molting cycle, and that when trxr-1 and gsr-1 function is reduced, disulfide groups in the cuticle remain oxidized. A selenocysteine-to-cysteine TRXR-1 mutant fails to rescue molting defects. Furthermore, worms lacking SELB-1, the C. elegans homolog of Escherichia coli SelB or mammalian EFsec, a translation elongation factor known to be specific for selenocysteine in E. coli, fail to incorporate selenocysteine, and display the same phenotype as those lacking trxr-1. Thus, TRXR-1 function in the reduction of old cuticle is strictly selenocysteine dependent in the nematode. Exogenously supplied reduced glutathione reduces disulfide groups in the cuticle and induces apolysis, the separation of old and new cuticle, strongly suggesting that molting involves the regulated reduction of cuticle components driven by TRXR-1 and GSR-1. Using dauer larvae, we demonstrate that aged worms have a decreased capacity to molt, and decreased expression of GSR-1. Together, our results establish a function for the selenoprotein TRXR-1 and GSR-1 in the removal of old cuticle from the surface of epidermal cells