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段舜山, 刘晓娟, 李爱芬
食品研究与开发2006, Vol. 27, No. 8,-0001,():
-1年11月30日
二十碳五烯酸(EPA)具有的重要作用引起人们广泛关注,微藻是生产EPA的最佳来源。许多微藻具有利用有机碳进行兼养和异养的能力,可以弥补自养培养光限制的不足,并且提高了EPA产量。综述了碳、氮和磷等几种重要营兼养和异养3种培养方式生产EPA的影响,阐明兼养和异养是微藻生产EPA的有效培养方式。
微藻, 二十碳五烯酸, 自养, 兼养, 异养
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【期刊论文】Zooplankton Distribution in Tropical Reservoirs, South China
段舜山, QIU-QI LIN, SHUN-SHAN DUAN, REN HU BO-PING HAN
,-0001,():
-1年11月30日
The zooplankton of 18 reservoirs of South China was investigated in 2000. 61 Rotifera species, 23 Cladoceras and 14 Copepodas were identified. The most frequent Rotifera genera were Keratella, Brachionus, Trichocerca, Diurella, Ascomorpha, Polyarthra, Ploesoma, Asplanchna, Pompholyx and Conochilus. Bosmina longirostris, Bosminopsis deitersi, Diaphanosoma birgei, D. brachyurum and Moina micrura were typical of Cladocera in the reservoirs. Phyllodiaptomus tunguidus, Neodiaptomus schmackeri and Mesocyclops leuckarti were the most frequent Copepoda and M. leuckarti dominated Copepoda in most reservoirs. High zooplankton species richness with low abundance was characteristic of the throughflowing reservoir, whereas low species richness with low abundance was found in the reservoir with the longest retention time. Relative high abundance and medium species diversity were the distinction of intermediate retention time reservoirs.
Zooplankton, species richness, abundance, retention time, tropical reservoirs
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【期刊论文】Peptidemodelsoffourpossibleinsulinfoldingintermediateswithtwodisulfides
段舜山, XIAO-YUA NJIA, ZHAN-YUN GUO, YAOWANG, YEXUSHUN-SHANDUAN, YOU-MINFENG
Protein Science (2003), 12:2412-2419. Published by Cold Spring Harbor Laboratory Press. Copyright,-0001,():
-1年11月30日
The single-chain insulin (PIP) can spontaneously fold into native structure through preferred kinetic inter-mediates. During refolding, pairing of the first disulfide A20–B19 is highly specific, whereas pairing of the second disulfide is likely random because two two-disulfide intermediates have been trapped. To get more details of pairing property of the second disulfide, four model peptides of possible folding intermediates with two disulfides were prepared by protein engineering, and their properties were analyzed. The four model peptides were named [A20–B19, A7–B7]PIP, [A20–B19, A6–B7]PIP, [A20–B19, A6–A11]PIP, and [A20– B19, A7–A11]PIP according to their remaining disulfides. The four model peptides all adopt partially folded structure with moderate conformational differences. In redox buffer, the disulfides of the model peptides are more easily reduced than those of the wild-type PIP. During in vitro refolding, the reduced model peptides share similar relative folding rates but different folding yields: The refolding efficiency of the reduced [A20–B19, A7–A11]PIP is about threefold lower than that of the other three peptides. The present results indicate that the folding intermediates corresponding to the present model peptides all adopt partially folded conformation, and can be formed during PIP refolding, but the chance of forming the intermediate with disulfide [A20–B19, A7–A11] is much lower than that of forming the other three intermediates.
Insulin, folding, intermediate, disulfide bonds, kinetics
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段舜山, Feng-Rui Li, Ai-Sheng Zhang, Shun-Shan Duan, Ling-Fen Kang
F.-R. Li et al. Acta Oecologica 28 (2005) 57-64,-0001,():
-1年11月30日
The perennial chenopod sub-shrub Artemisia halodendron Turcz. ex Bess. is endemic to the semi-xed and mobile sand dunes in Inner Mongolia of northern China and is an important sand-stabilizing plant. A. halodendron can persist through either sexual reproduction (seed- ling recruitment) or vegetative propagation. However, it is not known if there are differences in patterns of reproductive allocation in A. halodendron inhabiting semi-xed and mobile habitats. To characterize this, a test of eld measurements was conducted on two typical semi-xed and mobile sand dune habitats. In each habitat, 120 individual A. halodendron plants were randomly sampled at the time of seed production to examine changes in some reproductive characters including the number of owering shoots, dry weight of owering shoots, dry weight per owering shoot, dry weight of seed, and reproductive effort (RE = seed dry weight/total above-ground dry weight) between habitats. Although total above-ground dry weight and dry weight of vegetative biomass were similar between habitats, plants inhabiting the less eroded semi-xed habitat produced more owering shoots, greater dry weight of owering shoots, dry weight of seed and RE than those inhabiting the more eroded mobile habitat. This suggests that sexual reproduction is relatively favored by plants from the semi-xed habitat, whereas vegetative propagation is favored by plants from the mobile habitat. The allocation of resources to reproduction was size-dependent and specic to habitats sampled. Reproductive biomass and the number of owering shoots per plant increased with increasing vegetative biomass, with plants in the semi-xed habitat producing more owering shoots and greater reproductive biomass than plants in the mobile habitat. Plant size did not inuence RE, indicating that allocation of resources to reproduction appeared to be a constant proportion across all plant sizes sampled.
Environmental heterogeneity, Mobile sand dune, Reproductive effort, Semi-xed sand dune, Sexual reproduction, Vegetative propagation
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段舜山, Chen Lin, Ji-Guang Gu, Chuanling Qiao, Shunshan Duan, Ji-Dong Gu,
Biol Fertil Soils (2006) 42: 395-401,-0001,():
-1年11月30日
Degradation of three herbicides, atrazine, cyanazine and dicamba, was assessed in laboratory microcosms incubated under simulated methanogenic conditions using sediment from Pearl River of Southern China as an inoculum. Atrazine was much more resistant to degradation than cyanazine and dicamba over 300 days of incubation. Biodegradation of cyanazine and dicamba was further substantiated by establishment of enrichment transfer cultures in which the degradation of the respective herbicide was accelerated by the active microorganisms. Degradation of cyanazine initially involved the removal of chlorine and the two side chains, while that of dicamba was O-demethylation reaction forming 3, 6-dichlorosalicyclic acid. Results suggest that biodegradation of xenobiotics can be established through enrichment culture transfer technique, and further mechanism of degradation and microorganisms involved can be elucidated.
Atrazine, Cyanazine, Degradation Dicamba, Enrichment, Herbicide, Methanogenic conditions
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