Medium-induced radiative kernel with the Improved Opacity Expansion

We calculate the fully differential medium-induced radiative spectrum at next-to-leading order (NLO) accuracy within the Improved Opacity Expansion (IOE) framework. This scheme allows us to gain analytical control of the radiative spectrum at low and high gluon frequencies simultaneously. The high frequency regime can be obtained in the standard opacity expansion framework in which the resulting power series diverges at the characteristic frequency ωc ∼ $$ \hat{q} $$ q ̂ L2. In the IOE, all orders in opacity are resumed systematically below ωc yielding an asymptotic series controlled by logarithmically suppressed remainders down to the thermal scale T « ωc, while matching the opacity expansion at high frequency. Furthermore, we demonstrate that the IOE at NLO accuracy reproduces the characteristic Coulomb tail of the single hard scattering contribution as well as the Gaussian distribution resulting from multiple soft momentum exchanges. Finally, we compare our analytic scheme with a recent numerical solution, that includes a full resummation of multiple scatterings, for LHC-inspired medium parameters. We find a very good agreement both at low and high frequencies showcasing the performance of the IOE which provides for the first time accurate analytic formulas for radiative energy loss in the relevant perturbative kinematic regimes for dense media.

Simultaneous Isolation and Enumeration of Virulent Vibrio Cholerae and Vibrio Vulnificus using an Advanced MPN-PCR Method

Vibrio cholerae and Vibrio vulnificus are one of the critical foodborne pathogens that need to be intensively controlled their infection as a result of the intake and distribution of seafood, especially raw oysters. For this reason, various methods have already been developed for the detection and enumeration of these bacteria. The most probable number (MPN)-PCR (polymerase chain reaction) method is commonly used with the selective-differential medium for the efficiency and convenience of cell enumeration. One of the most frequently used for the detection of Vibrio spp. is Thiosulfate-Citrate-Bile salts-Sucrose (TCBS) agar. But this selective-differential medium can fail to distinguish between V. cholerae, V. vulnificus, and Vibrio alginolyticus. For this reason, the conventional MPN-PCR method with TCBS medium for the detection of Vibrio spp. has a problem that processing PCR to the two-times. This study suggests a simple and minimized detection method using one-time PCR and non-NaCl Luria-Bertani (LB-0) medium culture. This detection method is based on the difference in salt requirement between V. cholerae and V. vulnificus. Employing the developed methodology, the simultaneous cell enumeration of V. cholerae and V. vulnificus can be possible at a low cost. Furthermore, this study proposes a new specific primer to detect virulence-related genes from V. cholerae and V. vulnificus. This advanced MPN-PCR method was verified using bioaccumulated pacific oysters (Crassostrea gigas) by V. cholerae and V. vulnificus.

Selection of uric acid oxidizing-Lactobacillus plantarum isolates based on their genetic determinant and uricase kinetics

Hyperuricemia is a condition characterized by abnormally elevated levels of uric acid in the blood. It has been a leading morbidity disease. Microbial uricase can be used to oxidize uric acid into allantoin and hydrogen peroxide in the presence of oxygen and therefore has the potential to play an essential role in reducing uric acid in the people suffering from degenerative disease of hyperuricemia. The present study aims to select uric acid oxidizing-Lactobacillus plantarum isolates based on their genetic determinant and uricase kinetics. A collection of Lactobacillus plantarum isolates were grown on a selective differential medium followed by measuring their uricase activity spectrophotometrically. Specific primers for detection of uricase gene were designed. The uricase coding gene (uox) was then detected in all of the selected isolates by using a qPCR method employing the designed specific primers. The uricase kinetics was determined by the Lineweaver-Burk method. Results showed that all isolates had uricase activity and 4 potential isolates were selected based on their superior uricase activity. The uox gene was detected in all of the selected isolates. The kinetics analysis, however, revealed that only the L. plantarum K-Mar-A2 show strongest substrate affinity and was considered a potential candidate to be developed as a source of therapeutic agent for hyperuricemia.

Viability-PCR Allows Monitoring Yeast Population Dynamics in Mixed Fermentations Including Viable but Non-Culturable Yeasts

The use of controlled mixed inocula of Saccharomyces cerevisiae and non-Saccharomyces yeasts is a common practice in winemaking, with Torulaspora delbrueckii, Lachancea thermotolerans and Metschnikowia pulcherrima being the most commonly used non-Saccharomyces species. Although S. cerevisiae is usually the dominant yeast at the end of mixed fermentations, some non-Saccharomyces species are also able to reach the late stages; such species may not grow in culture media, which is a status known as viable but non-culturable (VBNC). Thus, an accurate methodology to properly monitor viable yeast population dynamics during alcoholic fermentation is required to understand microbial interactions and the contribution of each species to the final product. Quantitative PCR (qPCR) has been found to be a good and sensitive method for determining the identity of the cell population, but it cannot distinguish the DNA from living and dead cells, which can overestimate the final population results. To address this shortcoming, viability dyes can be used to avoid the amplification and, therefore, the quantification of DNA from non-viable cells. In this study, we validated the use of PMAxx dye (an optimized version of propidium monoazide (PMA) dye) coupled with qPCR (PMAxx-qPCR), as a tool to monitor the viable population dynamics of the most common yeast species used in wine mixed fermentations (S. cerevisiae, T. delbrueckii, L. thermotolerans and M. pulcherrima), comparing the results with non-dyed qPCR and colony counting on differential medium. Our results showed that the PMAxx-qPCR assay used in this study is a reliable, specific and fast method for quantifying these four yeast species during the alcoholic fermentation process, being able to distinguish between living and dead yeast populations. Moreover, the entry into VBNC status was observed for the first time in L. thermotolerans and S. cerevisiae during alcoholic fermentation. Further studies are needed to unravel which compounds trigger this VBNC state during alcoholic fermentation in these species, which would help to better understand yeast interactions.

Assessing the impact of quercetin isolated from Ammi majus seeds upon Candida spp. isolants isolated from different sources

Quercetin has been extracted from Ammi majus plant using ethanol via soxhlet system. Further, the substance was diagnosed by three binary and mono-layered chromatographical devices beside chronographical quantitative separation. Total of 45 patients was inflicted with mouth infections and urinary tract in both genders. The momentary vaginal infections among different ages of people settled in different regions of Nineveh district / Iraq were considered for the study. The study patients were identified using microscopic testing, selective differential medium (CHROM candida agar) and Vitek system. The isolation results inferred that the mouth infection is caused by most yeasts such as Candida parapsilosis (the most frequent),. The urinary tract infection is concerned, and most of the infections were reportedly caused by C. parapsilosis, C. tropicalis and C. albicans. with regards to the vaginal infections cases, C. albicans fungus has been the most frequent. Bio chemical tests were conducted using Vitek for the isolants studied, in which there were differences in the study results. Quercetin was extracted from Candid spp. The increase in the inhibition of quercetin is noted, whenever its concentration is increased. With regards to the anti-fungals Nystantin, for the concentration of 100IU/ml.and Clotrimazole 30mg/ml had inhibited the yeast Candid spp.

PREPARATION DIFFERENTIAL CULTURE MEDIUM FOR CRYPTOCOCCUS NEOFORMANS FROM AQUEOUS EXTRACT OF LEAVES AND FLOWERS OF CHRYSANTHEMUM CINERARIAEFOLIUM

Objective: A new medium was prepared to isolate and diagnose the yeast Cryptococcus neoformans from flower and leaves aqueous extract of chrysanthemum. Methods: Prepared differential culture medium for C. neoformans from aqueous extract of leaves and flowers of Chrysanthemum cinerariaefolium and chemical, spectral tests of the extracts were tested, in addition of gas chromatography (GC)–mass was used to diagnose phenolic compounds in both leaves and flowers. Results: Showed that the yeast was grow with typical colonies on the new medium compared with other media which using in diagnosed of this yeast such as Staib agar and Sabourauds dextrose agar and unlike the yeast Candida albicans (as a negative control), which appeared in cream to white on this medium. Furthermore, the colonies are dark brown in color on flower chrysanthemum medium and light brown color on leaves chrysanthemum medium. In addition, the results of the chemical and spectral tests of the extracts confirmed that the plant contains many active compounds such as alkaloids, turbines, tannins, and phenols. The analysis of the extracts of phenolic compounds using GC–mass led to the diagnosis of five compounds in the leaf extract and nine compounds in the flower extract of this plant. Conclusions: The media was prepared is differential medium that use to diagnosis of Cryptococcus such as Staib agar. Moreover, low economic cost, which consists of leaves and flowers of a plant available, abundance and the method of preparation is very simple.

Effect of Talc as a Dry-Inoculation Carrier on Thermal Resistance of Enterococcus faecium NRRL B-2354 in Almond Meal

ABSTRACTDry inoculation (DI) methods using a dry carrier have gained considerable interest for assessing thermal inactivation of Salmonella and other microorganisms in low-moisture foods. However, the effect of carrier residues on microbial resistance to heat remains largely unknown. This study aimed to determine the effect of talc powder on thermal resistance of Enterococcus faecium NRRL-B2354 (a Salmonella surrogate) in almond meal at 0.45 water activity (aw). Whole almonds were either immersed in an E. faecium suspension for wet inoculation (WI) or mixed with inoculated talc powder for DI. Two additional experimental conditions, inoculation of WI almond meal with added uninoculated talc (WT) and inoculated talc powder alone, were conducted. After WI, DI, and WT, the almonds were equilibrated to 0.45 aw, ground into a meal, and reequilibrated to 0.45 aw. Isothermal treatments were performed by heating almond meal (about 1 g) in aluminum test cells in a water bath at 80°C, with samples collected at more than five sequential time points from triplicate isothermal runs. E. faecium was enumerated by immediately cooling, diluting, and plating the samples on a nonselective or differential medium. E. faecium was more thermally resistant in DI (D80°C: 63.5 ± 1.9 min) compared with WI almond meal (D80°C: 40.5 ± 1.0 min; P < 0.05), but the resistance in WT almond meal (46.9 ± 0.9 min) was between and different from (P < 0.05) both DI and WI. E. faecium was less resistant in talc powder alone (20.6 ± 1.1 min) compared with all other almond meal samples. Overall, residual talc affected the thermal resistance of E. faecium. Therefore, when determining thermal resistance or validating commercial processes, carriers such as talc should not be used for inoculation of low-moisture foods without first knowing their impact on the target organism.HIGHLIGHTS

IMPROVEMENT OF THE CONTENT OF THE DRIGALSKI LACTOSE AGAR NUTRIENT MEDIUM

The purpose of the study is to improve the mix formulation of the Drigalski Lactose Agar breeding ground, produced by AppliChem, and aimed at enterobacteria isolation and differentiation. Development of a new mix formulation for the Drigalski Lactose Agar breeding ground, efficient assessment of cultivation of enterobacteria on its improved base and other breeding grounds used in the laboratory practice by the authors was the task of the study. The im-proved agar Drigalsky differential medium with lactose is recommended for cultivation (isolation) of different enter-obacteria of Enterobacteriaceae family.Differentiation of enterobacteria on improved medium is carried out accord-ing to their ability to ferment lactose, mannitol, glucose, sucrose, gelatin and form hydrogen sulfide. The medium can also be used for sanitary and microbiological examination of environmental objects.The medium can be used also to conduct the ONPG test. The efficiency of cultivation of enterobacteria isolated from various animal species on the most frequently used differential diagnostic medium, including new formulation of the Drigalski Lactose Agar, ranged from 16.28 ± 1.44 to 42.18 ± 4.12 hours. Enterobacteria isolated from farm and wild animals formed colo-nies on improved Drygalsky agar with lactose during 24 hours, and enterobacteria isolated from zoo animals within 25-31 hours.

Kinetic study on aminolysis of aryl X-substituted-cinnamates in acetonitrile: differential medium effect determines reactivity and reaction mechanism

A kinetic study on nucleophilic substitution reactions of 2,4-dinitrophenyl X-substituted-cinnamates (1a–1f) and Y-substituted-phenyl cinnamates (2a–2g) with a series of alicyclic secondary amines in MeCN at 25.0 ± 0.1 °C is reported. The Brønsted-type plots for the reactions of 1a–1f are linear with βnuc = 0.47∼0.50, indicating that the bond formation between the amine nucleophile and the electrophilic center is advanced slightly in the transition state. The Brønsted-type plot for the reactions of 2a–2g with piperidine is also linear with βlg = –0.66, which is a typical βlg value for reactions reported previously to proceed through a concerted mechanism. Furthermore, the Hammett plot correlated with σ– constants results in much better linearity than that correlated with σo constants, implying that expulsion of the leaving group is advanced in the rate-determining step (RDS). Thus, the reactions are concluded to proceed through a concerted mechanism. The Hammett plots for the reactions of 1a–1f consist of two intersecting straight lines, whereas the corresponding Yukawa–Tsuno plots exhibit excellent linear correlations with ρX = 0.62∼0.71 and r = 0.65∼0.68. Apparently, the nonlinear Hammett plots are not due to a change in the reaction mechanism (or the RDS) but are caused by stabilization of the substrate possessing an electron-donating group (EDG) in the cinnamoyl moiety through resonance interactions between the EDG and the C=O bond of the substrate. Medium effects on reactivity and reaction mechanism are also discussed.

Analisis Bakteri secara Kuantitatif pada Jajanan Kue Ku di Pasar Tradisional Bersehati Kota Manado (Quantitative Bacterial Analysis of “Kue Ku” in Bersehati Traditional Market Manado City)

Abstrak Pangan jajanan masih beresiko terhadap kesehatan karena penanganannya sering tidak higienis, yang memungkinkan jajanan Kue Ku terkontaminasi mikroba. Penelitian ini bertujuan untuk menganalisis bakteri secara kuantitatif pada jajanan Kue Ku di Pasar Tradisional Bersehati Kota Manado. Penelitian ini dilakukan dengan cara mengisolasi bakteri pada medium diferensial PCA (Plate Count Agar) selama 48 jam pada suhu 37°C kemudian dimurnikan lagi dengan medium selektif MCA (Mac Conkey Agar) dan medium diferensial NA (Nutrient Agar). Hasil penelitian menunjukkan bahwa analisis kuantitas bakteri pada jajanan Kue Ku di Pasar Tradisional Bersehati Kota Manado telah memenuhi syarat mutu batas maksimum cemaran mikroba yaitu pada tempat 1 berkisar 4 x 101 CFU/mL pada tempat 2 berkisar 3 x 101 CFU/mL dan pada tempat 3 berkisar 0,003 x 103 CFU/mL. Kata kunci: bakteri, koloni, kue jajanan Abstract “Kue Ku” as a kind of traditional cake is able to be contaminated by microbes because of unhygienic handling. This study aimed to analyze the bacteria quntitatively on “Kue Ku” cakes in Bersehati Traditional Market, Manado City. This study was conducted by isolating bacteria on PCA (Plate Count Agar) differential medium for 48 hours at 37 ° C then purified again with MCA (Mac Conkey Agar) selective medium and NA (Nutrient Agar) differential medium. The results showed that the number of bacteria on “Kue Ku” cake at Bersehati Traditional Market, Manado City fulfilled the quality requirement of maximum limit of microbial contamination, i.e. 4 x 101 CFU/mL (location 1), 3 x 101 CFU/mL (location 2), and 0.003 x 103 CFU/mL (location 3) . Keywords: bacteria, colony, traditional cake