Time filter

Source Type

Xiong Z.-J.,Yunnan University | Xiong Z.-J.,Xinjiang Institute of Ecology and Geography | Zhang Y.-G.,Yunnan University | Zhang Y.-G.,Xinjiang Institute of Ecology and Geography | And 7 more authors.
Antonie van Leeuwenhoek, International Journal of General and Molecular Microbiology | Year: 2013

A novel bacterium, designated YIM M13075T, was isolated from a sediment sample collected from the South China Sea. Growth occurred from 4 to 45 C (optimum 28 C), pH 6.0-11.0 (optimum pH 8.0). The strain formed yellow-cream colonies after 5 days incubation on TSA modified with 5 % NaCl medium at 28 C. Cells were Gram-positive, short rods and motile. Phylogenetic analyses based on 16S rRNA gene sequences indicated that strain YIM M13075T was affiliated with the genus Geomicrobium (93.5 %). The strain YIM M13075 T contained meso-diaminopimelic acid in the cell wall. The major polar lipids were diphosphatidylglycerol and phosphatidylglycerol. The major fatty acids were iso-C15:0 and anteiso-C15:0. The predominant menaquinones were MK-7 and MK-6. The genomic DNA G+C content was 42.7 mol%. On the basis of the morphological and chemotaxonomic characteristics as well as genotypic data, strain YIM M13075T represents a novel species in the genus Geomicrobium, for which the name Geomicrobium sediminis sp. nov. is proposed. The type strain is YIM M13075T (=DSM 25540 T =JCM 18144T =CCTCC AB 2013245T). An emended description of the genus Geomicrobium is also proposed in the light of the new data. © 2013 Springer Science+Business Media Dordrecht. Source

Ji G.,Nankai University | Ruan W.,China Agricultural University | Liu K.,Nankai University | Wang F.,Nankai University | And 12 more authors.
PLoS ONE | Year: 2013

Telomere reprogramming and silencing of exogenous genes have been demonstrated in mouse and human induced pluripotent stem cells (iPS cells). Pigs have the potential to provide xenotransplant for humans, and to model and test human diseases. We investigated the telomere length and maintenance in porcine iPS cells generated and cultured under various conditions. Telomere lengths vary among different porcine iPS cell lines, some with telomere elongation and maintenance, and others telomere shortening. Porcine iPS cells with sufficient telomere length maintenance show the ability to differentiate in vivo by teratoma formation test. IPS cells with short or dysfunctional telomeres exhibit reduced ability to form teratomas. Moreover, insufficient telomerase and incomplete telomere reprogramming and/or maintenance link to sustained activation of exogenous genes in porcine iPS cells. In contrast, porcine iPS cells with reduced expression of exogenous genes or partial exogene silencing exhibit insufficient activation of endogenous pluripotent genes and telomerase genes, accompanied by telomere shortening with increasing passages. Moreover, telomere doublets, telomere sister chromatid exchanges and t-circles that presumably are involved in telomere lengthening by recombination also are found in porcine iPS cells. These data suggest that both telomerase-dependent and telomerase-independent mechanisms are involved in telomere reprogramming during induction and passages of porcine iPS cells, but these are insufficient, resulting in increased telomere damage and shortening, and chromosomal instability. Active exogenes might compensate for insufficient activation of endogenous genes and incomplete telomere reprogramming and maintenance of porcine iPS cells. Further understanding of telomere reprogramming and maintenance may help improve the quality of porcine iPS cells. © 2013 Ji et al. Source

Gravel V.,Wageningen University | Gravel V.,Agriculture and Agri Food Canada | Blok W.,Wageningen University | Wang H.,North East Agricultural University | And 7 more authors.
Agronomy for Sustainable Development | Year: 2010

Soil-bound intensive greenhouse production has been scrutinized for its sustainability due to contamination of ground water by over-fertilization resulting in leaching of nutrients. As environmental guidelines are becoming more restrictive worldwide, and especially in Europe, many greenhouse growers have converted to more sustainable production systems including rockwool culture with recycled water and organic cropping systems in soil. The increase in popularity of organic production systems has amplified the debate whether organically grown produce is healthier than conventional produce. So far, little is known about the variations in fruit quality associated with production systems for greenhouse grown tomatoes. Thus, two organic (organic fertilization with and without straw amendment) and three conventional tomato cropping systems (regular and increased nutrient solution in rockwool and regular fertilization in soil) were compared in order to evaluate differences in nutrient availability and effects on fruit quality over a three-year period. Three modern medium-sized round tomato cultivars and one old cultivar were compared. There were no significant interactions between cropping systems and cultivars, so that main effects of systems and cultivars could be evaluated. Fruit yields in the organic systems were similar to those obtained in the conventional soil-bound system, but 15% lower than in the regular rockwool system, even though nitrogen concentrations in soil were not limiting in any of the production systems. Frequent organic amendments resulted in higher soil contents in the organic system without straw than in the other soil-bound systems, indicating that the organic systems were not yet stable in terms of nutrient availability after three years. A fruit quality index, based on the contents of compounds such as lycopene, β-carotene and vitamin C, was similar in all cropping systems. The old cultivar had a significantly higher quality index, but a lower yield than the other cultivars. According to this study, high quality tomatoes can be obtained through proper adjustment of the quantity and the source of nitrogen fertilizers in organic and conventional cropping systems and the use of selected cultivars with a high nutrient use efficiency for organic systems. © 2010 INRA, EDP Sciences. Source

Meng X.,Zhejiang University of Technology | Ye Q.,Zhejiang University of Technology | Nie X.,Zhejiang University of Technology | Pan Q.,China Agricultural University | Jiang L.,North East Agricultural University
JAOCS, Journal of the American Oil Chemists' Society | Year: 2015

Partial least squares (PLS) is a commonly used (and sometimes misused) chemometric technique for calibrating Fourier transform infrared spectroscopy, and allows the analysis of a variety of quality parameters associated with edible oils. Peroxide value (PV) is a typical parameter of interest; however, developing a robust, optimal, and reliable calibration method can be a daunting task. This paper examines and compares the use of interval PLS as a tool to develop a PLS PV calibration method for a single-bounce attenuated total reflectance accessory relative to full spectrum PLS and experienced PLS, making use of correlation, variance, and pure component spectra. Using mixtures of fresh and oxidized oil covering a PV range of 1-20 meq/kg, backward interval PLS could systematically produce quality calibrations without the need to resort to experienced PLS. The experienced PLS requires a degree of spectral knowledge as well as diligent and tedious spectral examination, including largely unstructured iterative calibrations and cross-validations to improve calibration performance. The backward interval PLS is also better than the full spectrum PLS in terms of model performance. In addition, the general model developed could account for the errors caused by oil types. © 2015 AOCS. Source

Shan Z.-Y.,Harbin Institute of Technology | Wu Y.-S.,Harbin Institute of Technology | Li X.,Harbin Institute of Technology | Shen X.-H.,Harbin Institute of Technology | And 4 more authors.
Cellular Reprogramming | Year: 2014

Induced pluripotent stem cells (iPSCs) are usually generated by reprogramming somatic cells through transduction with a transcription factor cocktail. However, the low efficiency of this procedure has kept iPSCs away from the study of the clinical application of stem cell biology. Our research shows that continuous passage increases the efficiency of reprogramming. Compared with conventional method of establishment of iPSCs, more embryonic stem cell (ESC)-like clones are generated by continuous passage during early reprogramming. These inchoate clones, indistinguishable from genuine ESC clones, are closer to fully reprogrammed cells compared with those derived from classical iPSC induction, which increased the expression of pluripotent gene markers and the levels of demethylation of Oct4 and Nanog. These results suggested that full reprogramming is a gradual process that does not merely end at the point of the activation of endogenous pluripotency-associated genes. Continuous passage could increase the pluripotency of induced cells and accelerate the process of reprogramming by epigenetic modification. In brief, we have provided an advanced strategy to accelerate the reprogramming and generate more nearly fully reprogrammed iPSCs efficiently and rapidly. © Mary Ann Liebert, Inc. Source

Discover hidden collaborations