Perovskite-organic tandem solar cells with indium oxide interconnect.

Multijunction solar cells can overcome the fundamental efficiency limits of single-junction devices. The bandgap tunability of metal halide perovskite solar cells renders them attractive for multijunction architectures1. Combinations with silicon and copper indium gallium selenide (CIGS), as well as all-perovskite tandem cells, have been reported2-5. Meanwhile, narrow-gap non-fullerene acceptors have unlocked skyrocketing efficiencies for organic solar cells6,7. Organic and perovskite semiconductors are an attractive combination, sharing similar processing technologies. Currently, perovskite-organic tandems show subpar efficiencies and are limited by the low open-circuit voltage (Voc) of wide-gap perovskite cells8 and losses introduced by the interconnect between the subcells9,10. Here we demonstrate perovskite-organic tandem cells with an efficiency of 24.0 per cent (certified 23.1 per cent) and a high Voc of 2.15 volts. Optimized charge extraction layers afford perovskite subcells with an outstanding combination of high Voc and fill factor. The organic subcells provide a high external quantum efficiency in the near-infrared and, in contrast to paradigmatic concerns about limited photostability of non-fullerene cells11, show an outstanding operational stability if excitons are predominantly generated on the non-fullerene acceptor, which is the case in our tandems. The subcells are connected by an ultrathin (approximately 1.5 nanometres) metal-like indium oxide layer with unprecedented low optical/electrical losses. This work sets a milestone for perovskite-organic tandems, which outperform the best p-i-n perovskite single junctions12 and are on a par with perovskite-CIGS and all-perovskite multijunctions13.

Creation of Rydberg Polarons in a Bose Gas.

We report spectroscopic observation of Rydberg polarons in an atomic Bose gas. Polarons are created by excitation of Rydberg atoms as impurities in a strontium Bose-Einstein condensate. They are distinguished from previously studied polarons by macroscopic occupation of bound molecular states that arise from scattering of the weakly bound Rydberg electron from ground-state atoms. The absence of a p-wave resonance in the low-energy electron-atom scattering in Sr introduces a universal behavior in the Rydberg spectral line shape and in scaling of the spectral width (narrowing) with the Rydberg principal quantum number, n. Spectral features are described with a functional determinant approach (FDA) that solves an extended Fröhlich Hamiltonian for a mobile impurity in a Bose gas. Excited states of polyatomic Rydberg molecules (trimers, tetrameters, and pentamers) are experimentally resolved and accurately reproduced with a FDA.

First industrial-grade coherent fiber link for optical frequency standard dissemination.

We report on a fully bidirectional 680 km fiber link connecting two cities for which the equipment, the setup, and the characterization are managed for the first time by an industrial consortium. The link uses an active telecommunication fiber network with parallel data traffic and is equipped with three repeater laser stations and four remote double bidirectional erbium-doped fiber amplifiers. We report a short-term stability at 1 s integration time of 5.4×10-16 in 0.5 Hz bandwidth and a long-term stability of 1.7×10-20 at 65,000 s of integration time. The accuracy of the frequency transfer is evaluated as 3×10-20. No shift is observed within the statistical uncertainty. We show a continuous operation over five days with an uptime of 99.93%. This performance is comparable with the state-of-the-art coherent links established by National Metrology Institutes in Europe. It is a first step in the construction of an optical fiber network for metrology in France, which will give access to an ultrahigh performance frequency standard to a wide community of scientific users.

Differential expression of immune-modulatory molecule HLA-E in non-neoplastic and neoplastic lesions of the thyroid.

Human leukocyte antigen (HLA)–E is a non-classical molecule of the histocompatibility complex that functions as one of the main ligands of the Natural Killer (NK) cell inhibitory receptor CD94/NKG2A and inhibits its potent cytotoxic activity. Due to the important role of NK cells in combating neoplasm, we hypothesized that the differential expression of HLA-E could favor the progression of heterogeneous thyroid tumors.Using an immunohistochemistry technique in 143 biopsies of thyroid tumors, including benign and malignant neoplasms and goiters, we evaluated the expression of HLA-E among various tumor types and its association with the clinicopathological factors of diseases. We verified high HLA-E expression in all types of neoplastic tumors, although no significant differences between the groups were found. Low expression was observed in 95 percent of the goiter samples, showing significant differences between neoplastic and non-neoplastic lesions. Furthermore, a significant result was found with regard to the tumor size, with high HLA-E expression being related to smaller tumors. Therefore, our data suggest that an increase in HLA-E may be associated with the establishment of thyroid neoplasms, with either benign or malignant features.

Properties of catechol 1,2-dioxygenase in the cell free extract and immobilized extract of Mycobacterium fortuitum.

Polycyclic aromatic hydrocarbons (PAH) are carcinogenic compounds which contaminate water and soil, and the enzymes can be used for bioremediation of these environments. This study aimed to evaluate some environmental conditions that affect the production and activity of the catechol 1,2-dioxygenase (C12O) by Mycobacterium fortuitum in the cell free and immobilized extract in sodium alginate. The bacterium was grown in mineral medium and LB broth containing 250 mg L(-1) of anthracene (PAH). The optimum conditions of pH (4.0-9.0), temperature (5-70 °C), reaction time (10-90 min) and the effect of ions in the enzyme activity were determined. The Mycobacterium cultivated in LB shown higher growth and the C12O activity was two-fold higher to that in the mineral medium. To both extracts the highest enzyme activity was at pH 8.0, however, the immobilized extract promoted the increase in the C12O activity in a pH range between 4.0 and 8.5. The immobilized extract increased the enzymatic activity time and showed the highest C12O activity at 45 °C, 20 °C higher than the greatest temperature in the cell free extract. The enzyme activity in both extracts was stimulated by Fe(3+), Hg(2+) and Mn(2+) and inhibited by NH(4+) and Cu(2+), but the immobilization protected the enzyme against the deleterious effects of K(+) and Mg(2+) in tested concentrations. The catechol 1,2-dioxygenase of Mycobacterium fortuitum in the immobilized extract has greater stability to the variations of pH, temperature and reaction time, and show higher activity in presence of ions, comparing to the cell free extract.

Quantification of bone marrow interstitial pH and calcium concentration by intravital ratiometric imaging.

The fate of hematopoietic stem cells (HSCs) can be directed by microenvironmental factors including extracellular calcium ion concentration ([Ca2+]e), but the local [Ca2+]e around individual HSCs in vivo remains unknown. Here we develop intravital ratiometric analyses to quantify the absolute pH and [Ca2+]e in the mouse calvarial bone marrow, taking into account the pH sensitivity of the calcium probe and the wavelength-dependent optical loss through bone. Unexpectedly, the mean [Ca2+]e in the bone marrow (1.0 ± 0.54 mM) is not significantly different from the blood serum, but the HSCs are found in locations with elevated local [Ca2+]e (1.5 ± 0.57 mM). With aging, a significant increase in [Ca2+]e is found in M-type cavities that exclusively support clonal expansion of activated HSCs. This work thus establishes a tool to investigate [Ca2+]e and pH in the HSC niche with high spatial resolution and can be broadly applied to other tissue types.

Evaluation of copper resistant bacteria from vineyard soils and mining waste for copper biosorption.

Vineyard soils are frequently polluted with high concentrations of copper due application of copper sulfate in order to control fungal diseases. Bioremediation is an efficient process for the treatment of contaminated sites. Efficient copper sorption bacteria can be used for bioremoval of copper from contaminated sites. In this study, a total of 106 copper resistant bacteria were examined for resistance to copper toxicity and biosorption of copper. Eighty isolates (45 from vineyard Mollisol, 35 from Inceptisol) were obtained from EMBRAPA (Empresa Brasileira de Pesquisa Agropecuária) experimental station, Bento Gonçalves, RS, Brazil (29°09'53.92″S and 51°31'39.40″W) and 26 were obtained from copper mining waste from Caçapava do Sul, RS, Brazil (30°29'43.48″S and 53'32'37.87W). Based on resistance to copper toxicity and biosorption, 15 isolates were identified by 16S rRNA gene sequencing. Maximal copper resistance and biosorption at high copper concentration were observed with isolate N2 which removed 80 mg L(-1) in 24 h. Contrarily isolate N11 (Bacillus pumilus) displayed the highest specific copper biosorption (121.82 mg/L/OD unit in 24 h). GenBank MEGABLAST analysis revealed that isolate N2 is 99% similar to Staphylococcus pasteuri. Results indicate that several of our isolates have potential use for bioremediation treatment of vineyards soils and mining waste contaminated with high copper concentration.

Shiga toxin-producing Escherichia coli and atypical enteropathogenic Escherichia coli strains isolated from healthy sheep of different populations in São Paulo, Brazil.

AIMS: Sheep are important carriers of Shiga toxin-producing Escherichia coli (STEC) in several countries. However, there are a few reports about ovine STEC in American continent. METHODS AND RESULTS: About 86 E. coli strains previously isolated from 172 healthy sheep from different farms were studied. PCR was used for detection of stx(1), stx(2), eae, ehxA and saa genes and for the identification of intimin subtypes. Restriction fragment length polymorphism (RFLP)-PCR was performed to investigate the variants of stx(1) and stx(2), and the flagellar antigen (fliC) genes in nonmotile isolates. Five isolates were eae(+) and stx(-), and belonged to serotypes O128:H2/beta-intimin (2), O145:H2/gamma, O153:H7/beta and O178:H7/epsilon. Eighty-one STEC isolates were recovered, and the stx genotypes identified were stx(1c)stx(2d-O118) (46.9%), stx(1c) (27.2%), stx(2d-O118) (23.4%), and stx(1c)stx(2dOX3a) (2.5%). Pulsed-field gel electrophoresis (PFGE) revealed 27 profiles among 53 STEC and atypical enteropathogenic Escherichia coli (EPEC) isolates. CONCLUSIONS: This study demonstrated that healthy sheep in São Paulo, Brazil, can be carriers of potential human pathogenic STEC and atypical EPEC. SIGNIFICANCE AND IMPACT OF THE STUDY: As some of the STEC serotypes presently found have been involved with haemolytic uraemic syndrome (HUS) in other countries, the important role of sheep as sources of STEC infection in our settings should not be disregarded.

Molecular identification and microbiological evaluation of isolates from equipments and food contact surfaces in a hospital Food and Nutrition Unit.

The hygienic and sanitary control in Food and Nutrition Units (FNU) is considered a standard procedure to produce adequate meals and reduce the risk of foodborne diseases and hospital infections. This study aimed to evaluate the isolation and identification of bacteria from equipment and food contact surfaces in a hospital FNU as well as to evaluate the sanitary condition. Likewise, it was analyzed the adhesion of the microorganisms on polyethylene cutting boards. The presence of aerobic mesophilic microorganisms, yeasts, molds, coagulase-positive staphylococci, coliform and fecal coliform, and Escherichia coli were analyzed on eating tables, countertop surfaces and cutting boards used for meat or vegetable handling, and equipment such as microwaves and refrigerators. The molecular identification it was done by 16S rRNA gene sequencing. The adhesion of the microorganisms (biofilm formation) on meat and vegetable cutting boards was also evaluated by scanning electron microscopy. The results showed high numbers of all microorganisms, except for E. coli , which was not observed in the samples. The molecular analysis identified species of the Enterobacteriaceae family and species of the Pseudomonadaceae family. Scanning electron microscopy analyses revealed bacterial adhesion on the cutting board surfaces. The results obtained in this study indicated that the hygienic conditions of surfaces like plastic cutting boards and equipment in this hospital FNU were inadequate. The achievement and application of standard operating procedures could positively help in the standardization of sanitary control, reducing the microbial contamination and providing a safe food to hospitalized patients.

Evaluation of dermatological effects of cosmetic formulations containing Saccharomyces cerevisiae extract and vitamins.

Saccharomyces cerevisiae extract (SCE) is used in cosmetics since it can act in oxidative stress and improve skin conditions. This study investigated dermatological effects of cosmetic formulations containing SCE and/or vitamins A, C and E. The formulation studied was supplemented or not (F1: vehicle) with vitamins A, C and E esters (F2) or with SCE (F3) or with the combination of vitamins and SCE (F4). Formulations were patch tested on back skin of volunteers. For efficacy studies, formulations were applied on volunteers and transepidermal water loss (TEWL), skin moisture (SM), skin microrelief (SMR) and free radicals protection were analysed after 3h, 15 and 30 days of application. Volunteers were also asked about efficacy perception. It was observed that F4 provoked a slight erythema in one volunteer. All formulations enhanced forearm SM. Only F3 and F4 presented long term effects on SMR and showed higher texture values; F3 had the highest brightness values. Our results suggest that vitamins and SCE showed effects in SM and SMR. Only formulations containing SC had long term effects in the improvement of SMR. Thus, these kinds of evaluations are very important in cosmetics development to evaluate the best risk and benefit correlation.

Entanglement and classical instabilities: fingerprints of electron-hole-to-exciton phase transition in a simple model.

We propose a schematic model to study the formation of excitons in bilayer electron systems. The phase transition is signalized both in the quantum and classical versions of the model. In the present contribution we show that not only the quantum ground state but also higher energy states, up to the energy of the corresponding classical separatrix orbit, "sense" the transition. We also show two types of one-to-one correspondences in this system: On the one hand, between the changes in the degree of entanglement for these low-lying quantum states and the changes in the density of energy levels; on the other hand, between the variation in the expected number of excitons for a given quantum state and the behavior of the corresponding classical orbit.

Plasma and urinary concentrations of trimetoquinol by LC-MS-MS following intravenous and intra-tracheal administration to horses with heaves.

Trimetoquinol (TMQ) is a very potent and fast acting bronchodilator in horses with heaves. This study assessed the plasma and urinary concentrations of TMQ in horses with heaves following administration via the intravenous (IV, 0.2 microg/kg) and intra-tracheal (IT, 2 microg/kg) routes. TMQ was administered to six horses affected with heaves (RAO - Recurrent Airway Obstruction, used interchangeably) by the above routes and plasma and urine samples collected and stored at -20 degrees C until analyzed. Solid Phase Extraction (SPE) of TMQ was followed by highly sensitive ESI(+)-LC-MS-MS (ElectroSpray Ionization, positive mode - Liquid Chromatography - Mass Spectrometry - Mass Spectrometry); with a Limit of Detection (LOD) estimated at 1 pg/mL. Following IV administration, TMQ plasma levels peaked at 1 min at 707 pg/mL, and at 9 min at 306 pg/mL following IT administration. Our results show that TMQ plasma concentrations decline rapidly following IV administration, which is consistent with the fast onset and short duration of TMQ effect that was observed in our previous studies. On the other hand, IT administration showed a very unique plasma concentration pattern. From a regulatory standpoint, the current available TMQ ELISA kit was also used in an attempt to detect TMQ from the plasma and urine samples. We report that the ELISA kit was unable to detect TMQ from any of the samples generated in these studies.

Soil macrofauna density and diversity across a chronosequence of tropical forest restoration in Southeastern Brazil.

Edaphic macrofauna must be better studied if we want to take advantage of their full potential for the restoration of tropical ecosystems. We investigated changes in edaphic macrofauna density and diversity along a secondary succession chronosequence in the Atlantic Forest. Our results show some clear patterns of change in soil macrofauna along the chronosequence. Density did not increase along secondary succession, but was correlated with canopy cover. Diversity was characterized by high dominance of social insects and evenness among other groups. We conclude soil macrofauna has a high capacity to recolonize young forests and that its recovery is considerably fast compared to other ecosystem transformations.

Management practices associated with strongylid parasite prevalence on horse farms in rural counties of Kentucky.

Anthelmintic resistance among cyathostomin parasites is a wide-spread problem. The parasite control guidelines written by the American Association of Equine Practitioners (AAEP) encourages the preservation of anthelmintic efficacy by reducing treatment frequency, using targeted deworming, and implementing environmental management practices. While there is knowledge regarding parasite management practices of affluent horse farms in the United States, surveys rarely explore the rural and underserved regions. The purpose of this study was to observe the management practices of horse farms in rural regions Kentucky, including working Amish farms, and determine factors associated with strongyle prevalence. A total of 160 horses among 38 owners from 28 different farms were enrolled in this study. A questionnaire survey regarding equine information, farm management, and deworming history was performed with each owner. Fecal samples were collected to determine fecal egg counts, perform coprocultures for subsequent strongyle larvae identification, and Strongylus vulgaris specific PCR. Serum samples were collected for the S. vulgaris antibody specific ELISA. The mean number of deworming treatments given in the last year was 2.1 with a 95% confidence interval of 1.9-2.3 with ivermectin being the most common active used. Statistical analysis showed horses treated within the last three months with a macrocylic lactone (ML) drug had significantly lower egg counts than horses treated with a ML 7-9 months ago (p = .0005). Despite the AAEP recommendations to reduce the overall number of treatments by using a surveillance-based approach and to no longer rotate treatments, only 17 horses reportedly had a fecal sample submitted for a fecal egg count and 65 horses were dewormed in a rotational manner. Horses whose owners utilized an informative deworming source (i.e., veterinarian, internet, magazine, local feed store) also had significantly lower counts (p = .0026). All coprocultures were negative for S. vulgaris while five horses were PCR positive. Interestingly, 95 horses tested ELISA positive for S. vulgaris. The strongyle egg counts of the working Amish horses were not significantly different from the other horses in this study and deworming practices including the use of efficacious drugs and low treatment frequencies were in accordance with the AAEP guidelines. This study was the first to summarize deworming management practices of rural regions in Kentucky, including a working Amish community. Overall, horse owners employed deworming practices recommended by the AAEP, however rotational deworming is still commonly implemented and fecal egg counts are rarely used.

Trimetoquinol: bronchodilator effects in horses with heaves following aerosolised and oral administration.

REASON FOR PERFORMING STUDY: The bronchodilator effects of trimetoquinol (TMQ) have been studied when administered i.v. or intratracheally, but not in an aerosolised form. OBJECTIVES: To define the relationship between the therapeutic and adverse responses (therapeutic index) of TMQ when administered as an aerosol or by the oral route. METHODS: Increasing doses of TMQ were administered to horses with heaves as an aerosol and by the oral route. Dose ranged 100-1000 microg/horse for aerosolised TMQ and from 6-60 microg/kg bwt for the oral route. Airway and cardiac effects were assessed by measurement of maximal change in pleural pressure (deltaPplmax) and heart rate (HR), respectively. Side effects of sweating, agitation and muscle trembling were scored subjectively. Duration of action of aerosolised (1000 pg/horse) and oral (6-60 microg/kg bwt) TMQ was evaluated over 6 h. RESULTS: Aerosol administration of TMQ caused dose-dependent bronchodilation but did not change HR or cause other observable side effects. When 1000 microg/horse was administered via aerosol, TMQ produced a 2-phase bronchodilation; an immediate effect lasting up to 30 min and a second phase between 2 and 4 h. Oral TMQ was therapeutically ineffective. CONCLUSION: Aerosol administration of TMQ is a safe and effective method of producing bronchodilation in horses.

Tramadol for osteoarthritis.

BACKGROUND: Tramadol is increasingly used for the treatment of osteoarthritis because, in contrast to nonsteroidal anti-inflammatory drugs (NSAIDs), tramadol does not produce gastrointestinal bleeding or renal problems, and does not affect articular cartilage. OBJECTIVES: We sought to determine the analgesic effectiveness, the effect on physical function, the duration of benefit and the safety of oral tramadol in people with osteoarthritis. SEARCH STRATEGY: We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE and LILACS databases up to August 2005. SELECTION CRITERIA: We included randomized controlled trials (RCTs) that evaluated the effect of tramadol or tramadol plus paracetamol on pain levels and/or physical function in people with osteoarthritis. No language restriction was applied. DATA COLLECTION AND ANALYSIS: We analyzed separately placebo-controlled and active-controlled studies. We used fixed-effect models for the meta-analyses as the results across studies were similar. MAIN RESULTS: We included eleven RCTs with a total of 1019 participants who received tramadol or tramadol/paracetamol and 920 participants who received placebo or active-control. The placebo-controlled studies indicated that participants who received tramadol had less pain (-8.5 units on a 0 to 100 scale; 95% confidence interval (CI) -12.0 to -5.0) than patients who received placebo. This represents a 12% relative decrease in pain intensity from baseline. Participants who received tramadol had a 37% increase (95% CI 1.2 to 1.5) in the likelihood of reporting moderate improvement (number needed to treat to benefit = 6; 95% CI 4 to 9). Participants who received tramadol had 2.27 times the risk of developing minor adverse events and 2.6 times the risk of developing major adverse events, compared to participants who received placebo. Of every eight people who receive tramadol or tramadol/paracetamol, one will stop taking the medication because of adverse events, number needed to treat to harm (NNTH)= 8 (95% CI 7 to 12) for major adverse events. No conclusion could be drawn on how tramadol or tramadol/paracetamol compared with available pharmacological treatments because of the limited number of studies that evaluated such therapies. AUTHORS' CONCLUSIONS: Tramadol or tramadol/paracetamol decreases pain intensity, produces symptom relief and improves function, but these benefits are small. Adverse events, although reversible and not life threatening, often cause participants to stop taking the medication and could limit tramadol or tramadol plus paracetamol usefulness.

Intravenous and intratracheal administration of trimetoquinol, a fast-acting short-lived bronchodilator in horses with 'heaves'.

REASON FOR PERFORMING STUDY: Trimetoquinol (TMQ) is a potent beta-adrenoceptor agonist bronchodilator used in human medicine but has not been evaluated for potential use as a therapeutic agent for horses with 'heaves'. OBJECTIVES: To assess the pharmacodynamics of TMQ in horses with 'heaves' to determine potential therapeutic effects. METHODS: Increasing doses of TMQ were administered to horses with 'heaves' by i.v. and intratracheal (i.t.) routes. Doses ranged 0.001-0.2 microg/kg bwt i.v. and 0.01-2 microg/kg bwt i.t. Cardiac and airways effects were assessed by measurement of heart rate (HR) and maximal change in pleural pressure (deltaPplmax), respectively. Side effects of sweating, agitation and muscle trembling were scored subjectively. Duration of action to i.v. (0.2 microg/kg bwt) and i.t. (2 microg/kg bwt) TMQ was evaluated over 6 h. RESULTS: Intravenous TMQ was an exceptionally potent cardiac stimulant. Heart rate increased at 0.01 microg/kg bwt, and was still increasing after administration of highest dose, 0.2 microg/kg bwt. Airway bronchodilation, measured as a decrease in deltaPplmax, also commenced at 0.01 microg/kg bwt. By the i.t. route, TMQ was 50-100-fold less potent than by i.v. Side effects included sweating, agitation and muscle trembling. Overall, the onset of HR and bronchodilator effects was rapid, within about 3 min, but effects were over at 2 h. CONCLUSION: When administered i.v. and i.t., TMQ is a highly potent cardiac stimulant and a modest bronchodilator. It may not be an appropriate pharmacological agent by i.v. and i.t. routes for the alleviation of signs in horses with 'heaves'. Further studies of TMQ by oral and aerosol routes are necessary. POTENTIAL RELEVANCE: In horses, TMQ is a fast-acting bronchodilator with a short duration of action. It could be used as a rescue agent during an episode of 'heaves'. The i.v. and i.t. administration of TMQ is associated with side effects, similar to those reported for all other beta-agonists. However, other routes, such as aerosol and oral, may prove useful and safe for the alleviation of bronchoconstriction typical of 'heaves'.

Evaluation of two Brazilian indigenous plants for phytostabilization and phytoremediation of copper-contaminated soils.

Indigenous plants have been grown naturally and vigorously in copper contaminated soils. Thus, the aim of this study was to evaluate the phytoremediation ability of two indigenous plants naturally grown in two vineyard soils copper contaminated, and in a copper mining waste. However, it was evaluated the macro and micronutrient uptake and the potential of phytoremediation. So, a greenhouse study was carried out with Bidens pilosa and Plantago lanceolata in samples of vineyard soils (Inceptisol and Mollisol) copper contaminated, and in a copper mining waste. Plant growth, macro and micronutrient up take, tolerance index (TI), translocation factor (TF), metal extraction ratio (MER), bioaccumulation factor (BCF), plant effective number of the shoots (PENs), and plant effective number of the total plant (PENt) were analyzed. Both plants grown in vineyard soils showed high phytomass production and TI. P. lanceolata plants cultivated in the Inceptisol showed the highest copper concentrations in the shoots (142 mg kg-1), roots (964 mg kg-1) and entire plants (1,106 mg kg-1). High levels of copper were phytoaccumulated from the Inceptisol by B. pilosa and P. lanceolata with 3,500 and 2,200 g ha-1 respectively. Both B. pilosa and P. lanceolata plants showed characteristics of high copper hyperaccumulator. Results showed that both species play an important role in the natural copper phytoaccumulation in both vineyard soils contaminated with copper, being important to its phytoremediation.

Antimicrobial and antioxidant activities of Enterococcus species isolated from meat and dairy products.

Lactic acid bacteria (LAB) have an important role in a great variety of fermented foods. In addition to their contribution to sensory characteristics, they enhance food preservation and can be used as probiotics. In this study, the antimicrobial and antioxidant activities of culture supernatants and cell free extracts of 16 LAB isolated from meat and dairy products were investigated. The bacterial were identified by 16S rRNA sequencing. GenBank BLAST analysis revealed that all the isolates belong to Enterococcus faecium species. Antimicrobial activity against the indicator microorganism (Listeria monocytogenes) was observed at 11 culture supernatants and 4 cell free extracts. The sensibility of culture supernatant was evaluated by proteinase K and trypsin and it was observed that activity of antimicrobial substance was completely lost after the treatment. All of the isolates showed antioxidant activity as determined by the Thiobarbituric Acid Reactive Substances (TBARS) method with both types of extracts. When the antioxidant capacity was investigated using ABTS•+ method (2,2 azino-bis (3-ethylbenzothiazoline-6-sulfonic acid)) and DPPH method (2,2-diphenyl-1-picrylhydrazyl) it was observed that only culture supernatants showed antioxidant capacity. These bacteria could particularly help to reduce or inhibit pathogenic microorganisms as well as oxidative spoilage in foods and feed.