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Single Culture (single + culture)
Selected AbstractsThe Composition of Jerusalem Artichoke (Helianthus tuberosus L.) Spirits Obtained from Fermentation with Bacteria and YeastsENGINEERING IN LIFE SCIENCES (ELECTRONIC), Issue 1 2005K. Szambelan Abstract The composition of spirits distilled from fermentation of Jerusalem artichoke (Helianthus tuberosus L.) tubers was compared by means of gas chromatography. The microorganisms used in the fermentation processes were the bacterium Zymomonas mobilis, strains,3881 and 3883, the distillery yeast Saccharomyces cerevisiae, strains,Bc16a and D2 and the Kluyveromyces fragilis yeast with an active inulinase. The fermentation of mashed tubers was conducted using a single culture of the distillery yeast Saccharomyces cerevisiae and the bacterium Zymomonas mobilis (after acid or enzymatic hydrolysis) as well as Kluyveromyces fragilis (sterilized mashed tubers). The tubers were simultaneously fermented by mixed cultures of the bacterium or the distillery yeast with K.,fragilis. The highest ethanol yield was achieved when Z.,mobilis,3881 with a yeast demonstrating inulinase activity was applied. The yield reached 94,% of the theoretical value. It was found that the distillates resulting from the fermentation of mixed cultures were characterized by a relatively lower amount of by-products compared to the distillates resulting from the single species process. Ester production of 0.30,2.93,g/L, responsible for the aromatic quality of the spirits, was noticed when K.,fragilis was applied for ethanol fermentation both in a single culture process and also in the mixed fermentation with the bacterium. Yeast applied in this study caused the formation of higher alcohols to concentrations of 7.04,g/L much greater than those obtained with the bacterium. The concentrations of compounds other than ethanol obtained from Jerusalem artichoke mashed tubers, which were fermented by Z.,mobilis, were lower than those achieved for yeasts. [source] Liver endothelial cells promote LDL-R expression and the uptake of HCV-like particles in primary rat and human hepatocytes,HEPATOLOGY, Issue 2 2006Yaakov Nahmias Low-density lipoprotein (LDL) is an important carrier of plasma cholesterol and triglycerides whose concentration is regulated by the liver parenchymal cells. Abnormal LDL regulation is thought to cause atherosclerosis, while viral binding to LDL has been suggested to facilitate hepatitis C infection. Primary hepatocytes quickly lose the ability to clear LDL during in vitro culture. Here we show that the coculture of hepatocytes with liver sinusoidal endothelial cells (LSEC) significantly increases the ability of hepatocytes to uptake LDL in vitro. LDL uptake does not increase when hepatocytes are cocultured with other cell types such as fibroblasts or umbilical vein endothelial cells. We find that LSECs induce the hepatic expression of the LDL receptor and the epidermal growth factor receptor. In addition, while hepatocytes in single culture did not take up hepatitis C virus (HCV)-like particles, the hepatocytes cocultured with LSECs showed a high level of HCV-like particle uptake. We suggest that coculture with LSECs induces the emergence of a sinusoidal surface in primary hepatocytes conducive to the uptake of HCV-like particles. In conclusion, our findings describe a novel model of polarized hepatocytes in vitro that can be used for the study of LDL metabolism and hepatitis C infection. (HEPATOLOGY 2006;43:257,265.) [source] Living and Teaching Across CulturesINTERNATIONAL STUDIES PERSPECTIVES, Issue 2 2001Raymond Cohen As long as one lives within the confines of a single culture it is difficult to achieve cross-cultural awareness. Multiculturalism is often simply the tolerance of a dominant culture for minority cultures. Cross-cultural awareness is a state of mind in which one is alert to alternity, the existence of others possessing different and equally valid world views and ways of life. This can be acquired living within or alongside other cultures, when one's own and others' strangeness become readily apparent. Culture shock involves just such a realization. The challenge for the teacher of international relations is to convey the possibility of alternity to students in the classroom. After all, international relations is above all about the interaction between communities possessing separate identities and autonomous wills. The article discusses ways of cultivating cross-cultural awareness, comparing the difficulties of doing so in a society under siege,Israel,with the greater scope available in the cosmopolitan setting of an elite American university. [source] Micropropagation of self-rooting juvenile clones by secondary somatic embryogenesis in Hevea brasiliensisPLANT BREEDING, Issue 2 2010Y. W. Hua With 2 figures and 5 tables Abstract Micropropagation of self-rooting juvenile clones in Hevea brasiliensis was established for two clones CATAS 7-33-97 and CATAS 88-13 through the following three steps: induction of primary embryos, embryo multiplication by secondary somatic embryogenesis in three successive cycles from a single culture of primary embryo and plant regeneration. The embryo multiplication coefficients of the two clones increased in the first cycle and reached the maximum in the second and the third cycle at the same rate. Significant effects of origins of embryo fragments and calcium on secondary embryogenesis were detected, the highest ratios of the regenerated embryos to primary embryos appeared, when embryo fragments close to the base of embryos were used and incubated in Murashige and Skoog (MS)-based callogenesis medium with 6.0 mm CaCl2 for CATAS 88-13 and 9.0 mm CaCl2 for CATAS 7-33-97. The highest rates of plant conversion were produced on MS-based plant regeneration medium with 4.5 and 9.0 ,m 2,4-D for CATAS 7-33-97 (85.0%) and 13.5 ,m for CATAS 88-13 (75.0%), being higher than other reports (60%). Finally, the application of this system was discussed. [source] Nutrient enrichment overwhelms diversity effects in leaf decomposition by stream fungiOIKOS, Issue 2 2003Felix Bärlocher Mass losses of oak leaves were studied in microcosms, where numbers of aquatic hyphomycete species (1,5) and nutrient concentrations (2 levels each of N, P, and Ca) were varied. Species numbers, species identities, N, P and N×P interactions all had significant effects on leaf mass loss, but the magnitude of the effect was greater for N and P than for species numbers. Mass loss in multicultures was greater than predicted from average contributions of the component species in single cultures. This may have been due to sampling effects or niche complementarity. [source] | ||||||||||