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101.
A new species, Allium pseudosenescens, belonging to sect. Rhizirideum (Alliaceae), is described from northeastern China. It is easily distinguished from A. senescens by the slender pedicels, pale pink perianths, narrower tepals and ovaries, yellowish anthers, and sometimes toothed subulate
filaments. Also, A. senescens var. minus in sect. Rhizirideum is raised to the rank of species, as A. minus. This Korean endemic taxon is shown to be a biologically distinct species based on morphological and cytological characters.
Taxonomic keys for the species of Allium sect. Rhizirideum in northeastern China and Korea are provided. 相似文献
102.
Kim JY Kim YG Han YK Choi HS Kim YH Lee GM 《Applied microbiology and biotechnology》2011,89(6):1917-1928
In order to understand the intracellular responses in recombinant CHO (rCHO) cells producing antibody in serum-free medium
(SFM) supplemented with optimized hydrolysates mixtures, yielding the highest specific growth rate (μ, SFM#S1) or the highest
specific antibody productivity (q
Ab, SFM#S2), differentially expressed proteins in rCHO cells are measured by two-dimensional gel electrophoresis combined with
nano-LC-ESI-Q-TOF tandem MS. The comparative proteomic analysis with basal SFM without hydrolysates revealed that the addition
of hydrolysate mixtures significantly altered the profiles of CHO proteome. In SFM#S1, the expression of metabolism-related
proteins, cytoskeleton-associated proteins, and proliferation-related proteins was up-regulated. On the other hand, the expression
of anti-proliferative proteins and pro-apoptotic protein was down-regulated. In SFM#S2, the expression of various chaperone
proteins and proliferation-linked proteins was altered. 2D-Western blot analysis of differentially expressed proteins confirmed
the proteomic results. Taken together, identification of differentially expressed proteins in CHO cells by a proteomic approach
can provide insights into understanding the effect of hydrolysates on intracellular events and clues to find candidate genes
for cell engineering to maximize the protein production in rCHO cells. 相似文献
103.
104.
Yoon SM Choi CH Kim M Hyun MS Shin SH Yi DH Kim HJ 《Journal of microbiology and biotechnology》2007,17(1):110-115
Electrochemically active bacteria were successfully enriched in an electrochemical cell using a positively poised working electrode. The positively poised working electrode (+0.7 V vs. Ag/AgCl) was used as an electron acceptor for enrichment and growth of electrochemically active bacteria. When activated sludge and synthetic wastewater were fed to the electrochemical cell, a gradual increase in amperometric current was observed. After a period of time in which the amperometric current was stabilized (generally 8 days), linear correlations between the amperometric signals from the electrochemical cell and added BOD (biochemical oxygen demand) concentrations were established. Cyclic voltammetry of the enriched electrode also showed prominent electrochemical activity. When the enriched electrodes were examined with electron microscopy and confocal scanning laser microscopy, a biofilm on the enriched electrode surface and bacterium-like particles were observed. These experimental results indicate that the electrochemical system in this study is a useful tool for the enrichment of an electrochemically active bacterial consortium and could be used as a novel microbial biosensor. 相似文献
105.
4-1BB costimulation enhances HSV-1-specific CD8+ T cell responses by the induction of CD11c+CD8+ T cells 总被引:2,自引:0,他引:2
Since 4-1BB plays a predominant role in CD8+ T cell responses, we investigated the effects of 4-1BB triggering on the primary and memory CD8+ T responses to HSV-1 infection. 4-1BB was detected on 10-15% of CD4+ and CD8+ T cells following the infection. 4-1BB-positive T cells were in the proliferative mode and showed the enhanced expression of anti-apoptotic proteins. Agonistic anti-4-1BB treatment exerted preferential expansion of CD8+ T cells and gB/H-2Kb-positive CD8+ T cells, and enhanced cytotoxicity against HSV-1 that was mainly mediated by CD11c+CD8+ T cells. CD11c+CD8+ T cells were re-expanded following re-challenge with HSV-1 at post-infection day 50, indicating that CD11c+CD8+ phenotype was maintained in memory CD8+ T cell pool. Our studies demonstrated that 4-1BB stimulation enhanced both primary and memory anti-HSV-1 CD8+ T cell responses, which was mediated by a massive expansion of antigen-specific CD11c+CD8+ T cells. 相似文献
106.
Saccharomyces cerevisiae strains tolerant to ethanol and heat stresses are important for industrial ethanol production. In this study, five strains
(Tn 1–5) tolerant to up to 15% ethanol were isolated by screening a transposon-mediated mutant library. Two of them displayed tolerance
to heat (42 °C). The determination of transposon insertion sites and Northern blot analysis identified seven putative genes
(CMP2, IMD4, SSK2, PPG1, DLD3, PAM1, and MSN2) and revealed simultaneous down-regulations of CMP2 and IMD4, and SSK2 and PPG1, down-regulation of DLD3, and disruptions of the open reading frame of PAM1 and MSN2, indicating that ethanol and/or heat tolerance can be conferred. Knockout mutants of these seven individual genes were ethanol
tolerant and three of them (SSK2, PPG1, and PAM1) were tolerant to heat. Such tolerant phenotypes reverted to sensitive phenotypes by the autologous or overexpression of
each gene. Five transposon mutants showed higher ethanol production and grew faster than the control strain when cultured
in rich media containing 30% glucose and initial 6% ethanol at 30 °C. Of those, two thermotolerant transposon mutants (Tn
2 and Tn 3) exhibited significantly enhanced growth and ethanol production compared to the control at 42 °C. The genes identified in
this study may provide a basis for the application in developing industrial yeast strains. 相似文献
107.
Chaperone-like activities of alpha-synuclein: alpha-synuclein assists enzyme activities of esterases
Ahn M Kim S Kang M Ryu Y Kim TD 《Biochemical and biophysical research communications》2006,346(4):1142-1149
Alpha-synuclein, a major constituent of Lewy bodies (LBs), has been implicated to play a critical role in the pathogenesis of Parkinson's disease (PD), although the physiological function of alpha-synuclein has not yet been known. Here we have shown that alpha-synuclein, which has no well-defined secondary or tertiary structure, can protect the enzyme activity of microbial esterases against stress conditions such as heat, pH, and organic solvents. In particular, the flexibility of alpha-synuclein and its C-terminal region seems to be important for complex formation, but the structural integrity of the C-terminal region may not be required for stabilization of enzyme activity. In addition, atomic force microscopy (AFM) and in vivo enzyme assays showed highly specific interactions of esterases with alpha-synuclein. Our results indicate that alpha-synuclein not only protects the enzyme activity of microbial esterases in vitro, but also can stabilize the active conformation of microbial esterases in vivo. 相似文献
108.
Choi J Ou JH 《American journal of physiology. Gastrointestinal and liver physiology》2006,290(5):G847-G851
Hepatitis C virus (HCV) is a major cause of viral hepatitis that can progress to hepatic fibrosis, steatosis, hepatocellular carcinoma, and liver failure. HCV infection is characterized by a systemic oxidative stress that is most likely caused by a combination of chronic inflammation, iron overload, liver damage, and proteins encoded by HCV. The increased generation of reactive oxygen and nitrogen species, together with the decreased antioxidant defense, promotes the development and progression of hepatic and extrahepatic complications of HCV infection. This review discusses the possible mechanisms of HCV-induced oxidative stress and its role in HCV pathogenesis. 相似文献
109.
Han Gil Choi Ji Hee Lee Young-Kug Choo Kyu-Yun Chai Young Sik Kim Jung-Soo Han Anchana Prathep Ki Wan Nam 《Phycological Research》2006,54(4):302-307
The seasonal growth and reproductive phenology of Neorhodomela aculeata (Perestenko) Masuda and Ceramium kondoi Yendo, and the food preferences of herbivorous snails were examined to elucidate (i) why snails select the fronds of N. aculeata for their habitat; and (ii) the survival strategies of the two red algae under grazing pressures. The maximal lengths and weights of both algal species were recorded for each season over a 12‐month period beginning with the spring of 2003. C. kondoi grew in length at a faster rate than N. aculeate, whereas the turf alga N. aculeata produced new branches from the tips of broken branches. The reproductive period of C. kondoi was between the spring and summer but the reproductive organs of N. aculeata were observed throughout the year. The algal loss rate of fresh N. aculeata to snails was low but snails had a food preference for N. aculeata when compared to C. kondoi in an artificial food experiment. These results indicate that snails may adapt to chemical compounds characteristic of N. aculeata and that the alga further reduces predation damage by its structural resistance. In conclusion, the survival strategies of C. kondoi appear to be rapid growth, seasonal sexual reproduction, and a delicately branched frond morphology that reduces stable feeding patterns of its predators plus high tissue nitrogen content, whereas the survival strategy of N. aculeata includes regenerative growth responses, structural toughness and chemical defenses while under the grazing pressure of herbivorous snails. 相似文献
110.
Jin-Ha?Lee Mi-Hwa?Choi Ji-Young?Park Hee-Kyoung?Kang Hwa-Won?Ryu Chang-Sin?Sunwo Young-Jung?Wee Ki-Deok?Park Do-Won?Kim Doman?KimEmail author 《Biotechnology and Bioprocess Engineering》2004,9(4):318-322
Lactic acid is an environmentally benign organic acid that could be used as a raw material for biodegradable plastics if it
can be inexpensively produced by fermentation. Two genes (IdhL andIdhD) encoding the L-(+) and D-(−) lactate dehydrogenases (L-LDH and D-LDH) were cloned fromLactobacillus sp., RKY2, which is a lactic acid hyper-producing bacterium isolated from Kimchi. Open reading frames ofIdhL for andIdhD for the L and D-LDH genes were 962 and 998 bp, respectively. Both the L(+)- and D(−)-LDH proteins showed the highest degree
of homology with the L- and D-lactate dehydrogenase genes ofLactobacillus plantarum. The conserved residues in the catalytic activity and substrate binding of both LDHs were identified in both enzymes. 相似文献