Biotehnološka primjena kvasca Yarrowia lipolytica uzgojenog u uvjetima nedostatka tiamina

During the cultivation of a thiamine-auxotrophic yeast strain Yarrowia lipolytica VKM Y-2412 on ethanol, the growth limitation by thiamine leads to the production of α-ketoglutaric acid. The α-ketoglutaric acid synthesis has been studied in dependence on pH, oxygen supply and ethanol, zinc and iron concentrations. Under optimal conditions, Y. lipolytica produced 88.7 g/L of α-ketoglutaric acid. The culture broth containing α-ketoglutaric acid was subjected to chemical treatment with hydrogen peroxide, which led to the formation of succinic acid in significant quantities (71.7 g/L). Further direct esterification of succinic acid with excess absolute ethanol yielded diethyl succinate. Biomass of Y. lipolytica, a superproducer of α-ketoglutaric acid, was characterized by a high content of protein and essential amino acids, free amino acids, and unusually large amount of γ-aminobutyric acid. The unique amino acid composition of the producer makes it possible to use this biomass as a component of parenteral nutrition mixtures and as a basis for neuroleptics.Auksotrofni kvasac Yarrowia lipolytica VKM Y-2412 uzgojen je na podlozi s etanolom u uvjetima nedostatka tiamina, što je dovelo do nastajanja α-ketoglutarne kiseline. Ispitana je ovisnost njezine sinteze o pH-vrijednosti, opskrbljenosti kisikom i etanolom, te koncentracijama cinka i željeza. U optimalnim je uvjetima kvasac Y. lipolytica proizveo 88,7 g/L α-ketoglutarne kiseline. Podloga za uzgoj koja je sadržavala α-ketoglutarnu kiselinu kemijski je obrađena vodikovim peroksidom, što je dovelo do nastajanja značajne koncentracije sukcinske kiseline (71,7 g/L). Daljnjom izravnom esterifikacijom sukcinske kiseline uz suvišak apsolutnog etanola dobiven je dietil sukcinat. Biomasu kvasca Y. lipolytica, koji proizvodi velike količine α-ketoglutarne kiseline, karakterizira veliki udjel proteina i esencijalnih aminokiselina, slobodnih aminokiselina i neuobičajeno velika količina γ-aminomaslačne kiseline. Jedinstveni aminokiselinski sastav kvasca omogućuje njegovu primjenu u intravenoznoj prehrani i pri liječenju pacijenata antipsihoticima

Spectroscopy of Baryons Containing Two Heavy Quarks in Nonperturbative Quark Dynamics

We have studied the three quark systems in an Effective Hamiltonian approach in QCD. With only two parameters: the string tension sigma and the strong coupling constant alpha_s we obtain a good description of the ground state light and heavy baryons. The prediction of masses of the doubly heavy baryons not discovered yet are also given. In particular, a mass of 3620 MeV for the lightest (ccu) baryon is found by employing the hyperspherical formalism to the three quark confining potential with the string junction.Comment: 8 pages, LaTe

Comment on the proper QCD string dynamics in a heavy-light system

The string correction to the inter-quark interaction at large distances is derived using the field theory approach to a heavy-light quark-antiquark system in the modified Fock-Schwinger gauge.Comment: LaTeX2e, 6 pages, no figures, to appear in JETP Let

Vibrating the QCD string

The large distance behaviour of the adiabatic hybrid potentials is studied in the framework of the QCD string model. The calculated spectra are shown to be the result of interplay between potential-type longitudinal and string-type transverse vibrations.Comment: LaTeX2e, 9 pages, 2 Postscript figures, final version to appear in Yad.Fi

Yield performance and stability of modern breeding stock of spring durum wheat (Triticum durum Desf.) from Russia and Kazakhstan

Identifcation of adaptive responses of breeding material, developed in different breeding centers, helps to purposefully correct these traits where it is necessary. Thus, 42 modern breeding lines from eight institutions of Russia and Kazakhstan were studied in comparison with the historical standard Bezenchukskaya 139 in trails of 16-17 and 18 KASIB-SDW (Kazakhstan-Siberian net for wheat improvement, spring durum wheat) in 2015–2017. Field experiments and yield measurements in each ecological cite were similar. To solve these tasks of the experiment, two-factor ANOVA, methods for adaptability assessment cluster analysis and principle component method were applied. As a result, it was established that 1) genotype and genotype – environment interaction (overall 15.8–23.5 % of total dispersion) had signifcant effect on yield variability; 2) genotype – environment interactions were of linear nature and had no destabilizing effect; 3) all the genotypes tested can be distributed in three clusters, the frst one for locally adapted varieties, the third for varieties of a wide areal, the second included genotypes with intermediate characteristics; 4) breeding centers of the Federal Altai Scientifc Centre of Agro-Biotechnologies and of the Research Institute of Agriculture of South-East produced predominantly varieties of local importance, the Samara Research Institute of Agriculture – varieties of wide area; 5) a stable trend of increased mean yield compared to historical standard Bezenchukskaya 139 over ecological sites was observed only for Samara varieties; 6) varieties of all the breeding centers had no stable difference from Bezenchukskaya 139 concerning stability and responsiveness, which can be explained by an incomplete breeding process for these parameters and confrms the importance of the KASIB program; 7) a trend of yield increase compared to Bezenchukskaya 139 under testing in defnite local environments had more stable parameters with the largest progress observed in the Altai Research Institute of Agriculture (135.4 and 163.2 % to Bezenchukskaya 139), which can be explained by a high efciency of breeding of locally adapted varieties in the breeding center

Kazakhstan-Siberian spring common wheat identification according to glutenin and gliadin composition

Within ten years, the Kazakhstan-Siberian nursery net for spring common wheat improvement (KASIB) working under the auspices of CIMMYT (Intenational Maize and Wheat Improvement Center) characterized accessions of five cultivar blocks with regard to the compositions of gliadin (1B/1R translocation), glutenin HMW and LMW subunits, and grain hardness. HMW glutenin compositions for 188 homogeneous variety samples are given in accordance with UPOV (Union for the Protection of New Varieties of Plants) regulations and 27, 28 and 29 features in tests for uniformity, distinctness, and stability. Most spring wheat cultivars possess the glutenin spectra 2* 7+9 5+10” (40 %), “2* 7+9 2+12” (up to 30 %), and “17+95+10” (8 %). The Kazakhstan varietal gene pool includes genotypes with a new subunit 4 + 10 on 1D in samples of Erythrospermum 55/94-01-20 and Phyton 41. Cultivar Iridost is noted as carrying the relatively rare allele 5,5 + 10 on chromosome 1D. This allele was previously identified in Tselinogradka, Tselinnaya 24, and Akmola 3 cultivars. The rare subunit 7*+ 8 is typically present in E-607 and E-757. The last three KASIB blocks (8-9; 10-11; 12-13) show higher levels of uniformity: up to 74–84 %. The 1BL.1RS wheat-rye translocation is more frequently identified in accessions by Siberian Scientific Research Institute of Agriculture and Eastern Kazakhstan Research Institute of Agriculture breeding in each KASIB block and also in all the accessions presented by the companies Kurgansemena and Agrosemkonsal and selected by the Fiton company. Varieties Altaiskaya 105, Kurganskaya 5, Lutescens 1300, Phyton 42, Lutescens 53/95-98-1, Lutescens 53/88-94-12, Lutescens 54; Lutescens 30-94, Erythrospermum 607, and Aktobe 1574 showed the whole range of variability in grain hardness (from middle soft to hard) under different growth conditions

A Thin-Layer Chromatography Method for the Determination of Essential Oil Components in Anise and Fennel Fruits

Scientific relevance. The State Pharmacopoeia of the Russian Federation, edition XIV, requires the identification of aniseed and fennel fruits by the same thin-layer chromatography (TLC) procedure using Sudan III and menthol. These markers are neither specific nor related to the therapeutic effects of these herbal drug products. The visual interpretation of chromatograms is complicated because of the low intensity of adsorption zones. Moreover, the corresponding compendial monographs do not characterise the adsorption zones specific to each of the plants. The most abundant component in aniseed and fennel essential oils, trans-anethole, would make a better reference standard from a methodological point of view.Aim. This study aimed to optimise the TLC procedure for essential oil determination in herbal drugs and herbal medicinal products of aniseed and fennel fruits and subsequently recommend it for inclusion in the relevant compendial monographs.Materials and methods. The study examined samples from several batches of herbal drugs, including aniseed and common fennel fruits, sourced from Russian manufacturers. The reference standards comprised commercial reagents, including trans-anethole, anise oil, and linalool, as well as fresh essential oils that had been steam distilled from the test samples in a Clevenger apparatus. The study was conducted by TLC. Sample preparation involved using Merck aluminium TLC plates, an IKA KS-501 digital orbital shaker, and a CAMAG Linomat 5 semi-automatic sample application system. The authors heated the plates in either a Binder ED53 drying oven or a CAMAG TLC plate heater. For visualisation, the authors selected a CAMAG TLC VISUALIZER 2 UV imaging and documentation system.Results. The informational and experimental research showed the feasibility of using trans-anethole as an identification reference standard for common anise and fennel fruits. The authors selected the optimal solvent for extracting active substances from the test products (hexane) and a detection reagent for improving visual evaluation of the chromatograms (1% sulfovanillin). The authors established characteristic adsorption zones for differentiating between aniseed and fennel fruits.Conclusions. The optimised procedure identifies the main components in the essential oils of aniseed and fennel fruits with a specific reference standard. This procedure may be recommended for inclusion in draft monographs for the corresponding herbal medicinal products

Determination of the Total Alkaloid Content of Thermopsis Dry Extract by HPTLC-Densitometry

When used to quantify alkaloids in thermopsis dry extract, acidimetric titration has several limitations, including insufficient specificity of the method and arbitrary selection of a titration endpoint. Different parts of the Thermopsis lanceolata plant produce alkaloids in different proportions: the herb is rich in thermopsine, whereas the seeds are rich in cytisine. Since thermopsine and cytisine have different pharmacological effects, it is important to identify and quantify individual alkaloids in thermopsis dry extract.The aim of the study was to develop and validate an analytical procedure for identifying and quantifying total alkaloids in thermopsis dry extract by high-performance thin-layer chromatography (HPTLC) with densitometric detection.Materials and methods. The study included samples from two pilot-scale batches of thermopsis dry extract and reference standards for cytisine and thermopsine. The authors used Merck HPTLС Silica Gel 60 F254 20×10 cm plates for chromato-graphic separation and analysed the results with a CAMAG® TLC Scanner 4 densitometer and the winCATS software.Results. The authors identified thermopsis dry extract using HPTLC separation followed by spectrodensitometry. The alkaloid-specific solution applied to chromatography plates helped to identify the three most abundant and four minor alkaloids of thermopsis. The most abundant alkaloids were thermopsine, cytisine, and an unidentified alkaloid with a retention factor of approximately 0.2. These three alkaloids accounted for almost 80% of the total alkaloid content of the dry extract. The authors quantified cytisine, thermopsine, and total alkaloids expressed as thermopsine.Conclusions. The authors developed and validated an analytical procedure for identifying and quantifying total alkaloids in thermopsis dry extract. This procedure offers the possibility of reducing the analysis time from 4–5 hours to 2–2.5 hours

POPULATION STRUCTURE OF LEAF PATHOGENS OF COMMON SPRING WHEAT IN THE WEST ASIAN REGIONS OF RUSSIA AND NORTH KAZAKHSTAN IN 2017

Wheat diseases affecting leaves like leaf rust (Puccinia triticina), tan spot (Pyrenophora tritici-repentis) and spot blotch (Сochliobolus sativus = Bipolaris sorokiniana) are widely spread and potentially dangerous in the West-Asian region of Russia and North Kazakhstan. The study of these pathogens’ populations is very important for genetic protection of wheat. The objective of this study was to explore the population structure of the causative agents of leaf rust and tan spot on spring wheat based on virulence traits and assessing the distribution of the causative agent of spot blotch in the West-Asian region of Russia and North Kazakhstan. The source of inoculum were wheat leaves affected by leaf rust and spot diseases collected in the Chelyabinsk and the Omsk region of Russia and in North Kazakhstan. Virulence analysis of P. triticina using 20 lines with known Lr genes demonstrated that all 109 monopustule isolates were avirulent on ТсLr24. The isolates virulent on ТсLr19 were identified only in the Chelyabinsk population. The prevalence of isolates virulent on ТсLr2a, ТсLr2b, ТсLr2c, ТсLr11, ТсLr15, ТсLr16, ТсLr20 and ТсLr26 was higher in the Omsk and the North Kazakhstani population, while virulence to ТсLr9 was higher in Chelyabinsk. Using 20 TcLr-lines, we identified 27 virulent phenotypes of P. triticina: 12 in the Omsk, 19 in the Chelyabinsk and 8 in the Kazakhstani population. The phenotypes TLTTR (avirulent to TcLr16, TcLr19, TcLr24, TcLr26), TCTTR (avirulent to TcLr9, TcLr16, TcLr19, TcLr24), and TBTTR (avirulent to TcLr9, TcLr16, TcLr19, TcLr24, TcLr26) were observed in all the populations. The phenotypes TQTTR (avirulent to TcLr19, TcLr24, TcLr26) and TGTTR (avirulent to TcLr9, TcLr19, TcLr24, TcLr26, TcLr9, TcLr19, TcLr24, TcLr26) were common in the Omsk and the North Kazakhstani population, while THPTR (avirulent to avTcLr9, TcLr11, TcLr19, TcLr24) and TCTTQ (avirulent to TcLr9, TcLr16, TcLr19, TcLr20, TcLr24) were common in the Omsk and the Chelyabinsk population. There was a high genetic similarity in virulence and phenotypic composition between the Omsk and the North Kazakhstani population as well as between the Omsk and the Chelyabinsk population and a moderate similarity between the Chelyabinsk and the North Kazakhstani population. The prevalence of the spot blotch pathogen was higher in the material collected from the Omsk region, while none of this pathogen was identified in the North Kazakhstani material. The isolates of tan spot were identified in all the regions. Five races of P. tritici-repentis were identified among Chelyabinsk isolates based on the toxins produced by the following pathogens: race 1 (PtrToxA PtrToxС); race 2 (PtrToxA); race 7 (PtrToxA, PtrToxВ), race 8 (PtrToxA, PtrToxВ, PtrToxС), and race 4 (does not produce toxins). Three races were identified in the Omsk region (1 – 3) and four, in North Kazakhstan (1 – 4). A total of 26 P. tritici-repentis phenotypes were identified by virulence analysis using 11 differential lines: two were present in all the populations; two. in Chelyabinsk and North Kazakhstan; one, in Omsk and Chelyabinsk; and all the others were original. A high degree of similarity between the obligate pathogen P. triticina and the saprophytic pathogen P. tritici-repentis in the West-Asian region of Russia and in North Kazakhstan demonstrates that this is one epidemiological region across this wheat production area. The presence of common phenotypes suggests there is a the possibility of gene exchange between the populations and this shall be considered while releasing genetically protected wheat varieties

From scalar to string confinement

We outline a connection between scalar quark confinement, a phenomenologically successful concept heretofore lacking fundamental justification, and QCD. Although scalar confinement does not follow from QCD, there is an interesting and close relationship between them. We develop a simple model intermediate between scalar confinement and the QCD string for illustrative purposes. Finally, we find the bound state masses of scalar, time-component vector, and string confinement analytically through semi-classical quantization.Comment: ReVTeX, 9 pages, 5 figure