Scheffersomyces stipitis PJH was mutagenized by random integrative mutagenesis and the integrants were screened for lacking the ability to grow with glutamate as sole carbon source. One of the two isolated mutants was damaged in the COX5 gene, which encodes a subunit of the cytochrome c oxidase. BLAST searches in the genome of Sc. stipitis revealed that only one singular COX5 gene exists in Sc. stipitis, in contrast to Saccharomyces cerevisiae, where two homologous genes are present. Mutant cells had lost the ability to grow with the amino acids glutamate, proline or aspartate and other non-fermentable carbon sources, such as acetic acid and ethanol, as sole carbon sources. Biomass formation of the mutant cells in medium containing glucose or xylose as carbon source was lower compared with the wild-type cells. However, yields and specific ethanol formation of the mutant were much higher, especially under conditions of higher aeration. The mutant cells lacked both cytochrome c oxidase activity and cyanide-sensitive respiration, whereas ADH and PDC activities were distinctly enhanced. SHAM-sensitive respiration was obviously essential for the fermentative metabolism, because SHAM completely abolished growth of the mutant cells with both glucose or xylose as carbon source. 相似文献
The genetically modified (GM) rice Kefeng?6 has gained resistance against several rice pests by inserting the cpti and cry1Ac genes. As this transgenic line is not approved for import, processing and cultivation in the European Union (EU), sensitive and specific detection methods need to be available to monitor any illegal presence of Kefeng?6 in food products within the EU. The aim of this study was to develop and validate an event-specific detection method by means of quantitative real-time PCR (qPCR) for the detection of Kefeng?6 in foodstuff. A primer pair and hydrolysis probe were designed according to the right border junction sequence of the transgene. The qPCR assay was validated according to the ENGL/EURL-GMFF guidelines for GMO testing and is presented according to the MIQE guidelines. The in-house validation process resulted in a limit of detection of 5 DNA copies of the transgene with confidence intervals (95?%) between 0.07 and 0.52, a PCR efficiency of 105?% and a correlation coefficient (R2) value of 0.9997. The specificity of the assay was tested by end-point PCR, gel electrophoresis and subsequent sequencing of the PCR products. By testing DNA of several GM and non-GM crops, cross reactivity of the assay was not observed. Further, 35 food products were analyzed for the presence of Kefeng?6 by means of the event-specific detection method. For 9 out of 35 samples, PCR products for Kefeng?6 DNA were observed. 相似文献
The curing of an epoxy consisting of the solid hardener dicyandiamide (DICY) and the resin diglycidyl ether of bisphenol A (DGEBA) is studied in a system consisting of a tablet of DICY embedded in liquid DGEBA. Dissolution of DICY within the liquid DGEBA in combination with the transport of dissolved DICY from the tablet border into DGEBA and the chemical reaction of both reactants is studied by scanning Brillouin microscopy and infrared spectroscopy. Scanning Brillouin microscopy demonstrates the spatial and temporal evolution of the static and dynamic hypersonic properties in the course of curing in the vicinity of the DICY tablet. Infrared spectroscopy performed on epoxy pieces extracted from the final sample at different distances from the tablet surface give information about the spatial evolution of the curing process. The results achieved by both techniques are finally combined to yield a better understanding of the curing of DICY-based epoxies, which transform upon curing from strongly heterogeneous systems towards increasingly homogeneous systems. 相似文献
The SUPRENUM idea, the project, and the system has generally been described and presented in several papers. There is also a great deal of more detailed technical papers describing SUPRENUM as a whole or certain elements of it.
Here we want to give only a very general and rough survey on the essentials of the SUPRENUM system in order to enable the reader to categorize and understand the more specific SUPRENUM papers in this special issue.
Most of the supercomputer applications today are based on grid or grid-like data structures. Grid applications play also an essential role in the SUPRENUM development: in the top-down design of the architecture, in the programming environment, in the parallelization concept of algorithms, and, of course, in the application software development itself. We therefore place some emphasis on this grid orientation in our presentation. 相似文献
The tear film is a multi-layer fluid that covers the corneal and conjunctival epithelia of the eye and provides lubrication, nutrients, and protection from the outside environment. Tear fluid contains a high concentration of proteins and has thus been recognized as a potential source of biomarkers for ocular disorders due to its proximity to disease sites on the ocular surface and the non-invasive nature of its collection. This is particularly true in the case of dry eye disease, which directly impacts the tear film and its components. Proteomic analysis of tear fluid is challenging mainly due to the wide dynamic range of proteins and the small sample volumes. However, recent advancements in mass spectrometry have revolutionized the field of proteomics enabling unprecedented depth, speed, and accuracy, even with small sample volumes. In this study using the Orbitrap Fusion Tribrid mass spectrometer, we compared four different mass spectrometry workflows for the proteomic analysis of tear fluid collected via Schirmer strips. We were able to establish a method of in-strip protein digestion that identified >3000 proteins in human tear samples from 11 healthy subjects. Our method offers a significant improvement in the number of proteins identified compared to previously reported methods without pooling samples. 相似文献
Important environmental parameters in arctic periglacial landscapes (i.e. permafrost temperature, active-layer depth, soil moisture, precipitation, vegetation cover) will very likely change in a warming climate. The thawing of permafrost, especially, might cause massive landscape changes due to thermokarst and an enhanced release of greenhouse gasses from the large amounts of carbon stored in frozen deposits, resulting in positive climate-warming feedback. For the identification, mapping, and quantification of such changes on various scales up to the entire circum-Arctic, remote sensing and spatial data analysis are essential tools. In this study an extensive field-work dataset including spectral surface properties, vegetation, soils, and geomorphology was acquired in the largest Arctic delta formed by a single river, the Siberian Lena River Delta. A portable field spectrometer (ASD FieldSpec Pro FR®) was used for spectral surveys of terrain surfaces, and optical satellite data (Landsat Enhanced Thematic Mapper (ETM+), CHRIS-Proba) were used for the characterization, manual mapping, and automatic classification of typical periglacial land-cover units in the Lena Delta. Qualitative data from soils, vegetation, soil moisture, and relief units were correlated with the field-spectral data and catalogued for a wide variety of surface types. The wide range of micro- and meso-scale variations of periglacial surface features in the delta results in distinctive spectral characteristics for different land-cover units. The three main delta terraces could also be spectrally separated and characterized. The present dataset provides a basis for further spectral data acquisitions in the Lena Delta and for comparisons with periglacial surfaces from other regions. 相似文献