摘要：
沼气发酵系统是一个复杂的生态系统,其污泥微生物超过99%是不可培养的。为了优化沼气池纤维素的转化效率、沼气的产率和开展污泥微生物多样性研究,本研究采用化学裂解法、溶菌酶裂解法和QIAampDNA Stool Mini Kit提取了沼气池污泥样品中微生物的总DNA,对三种方法的DNA得率、纯度、大片段提取效果以及是否含有PCR反应抑制剂进行了研究,最后对16S rRNA基因V3区的扩增产物进行了PCR变性梯度凝胶电泳（PCR-DGGE）分析。与化学裂解法和QIAamp DNA Stool Mini Kit法相比,溶菌酶裂解法得到的DNA量大、片段长、片段分布广、PCR扩增效率高;同时PCR-DGGE图谱显示,溶菌酶裂解法可更好地展示沼气池污泥中微生物的多样性。该结果为进一步提高沼气池中纤维素的转化效率和沼气生产优势菌种的质和量打下了一定的前期基础。
摘要：
Forty-eight German Landrace weaned pigs were used in this study to investigate the effects of Lfcin B and Cec P1 on performance, faecal score and DM of weaned piglets orally challenged with enterotoxigenic Escherichia coli F4. The piglets were assigned randomly into four groups: Control, enterotoxigenic Escherichia coli F4ac (ETEC), enterotoxigenic Escherichia coli F4ac (ETEC)+lactoferricin B (Lfcin B) and enterotoxigenic Escherichia coli F4ac (ETEC) +Cecropin P1 (Cec P1) on the basis of weight and litter. All piglets in three experimental groups were orally challenged with 3x109 cfu E.coli K88 O149:K91:F4ac on d 29 and 30. Lfcin B and Cec P1 were administered orally as a single dose of 2 mg per piglet on d 29 after being challenged ETEC F4ac 3 hours later. From the age of 30 days, the piglets were offered feed and water ad libitum. The results showed that there were no significant differences on daily weight, ADG and ADFI (P>0.05) of piglets among the four groups during the experimental period. From d 28 to 35, the piglets in Cec P1 groups kept higher daily weight (p>0.05) than those in other three groups. There were no differences for faecal score and feces dry matter among the four groups. But there was a tendency piglet in Cec P1 group kept the balance of faecal score and feces dry matter. Though there are no obvious effects, Lfcin B and Cec P1 have potential use without toxicity in vivo as additive in the husbandry product.
摘要：
Cold stress is one of the major abiotic stresses limiting the productivity and the geographical distribution of many important crops. To gain a better understanding of cold stress responses in tobacco ( Nicotiana tabacum ), we carried out a comparative proteomic analysis. Five-week-old tobacco seedlings were treated at 4°C for 4 h. Cold treatment resulted in stress phenotypes of smoothing and shallowing leaves and increased relative electrolyte leakage. The expression changes of total proteins in tobacco leaves were examined using two-dimensional electrophoresis. Quantitative image analysis revealed a total of 101 protein spots that changed their intensities significantly, 21 protein spots were down-regulated, eight were up-regulated after the cold treatment, 50 protein spots only expressed in the control sample, while 22 protein spots were only present in the cold treatment sample. Mass spectrometry analysis allowed the identification of 73 differentially expressed proteins, including well known and novel cold-responsive proteins. The identified proteins are involved in several processes such as photosynthesis, protein processing, redox homeostasis, ribonucleic acid (RNA) processing, signal transduction, translation, cell division/cycle, and metabolisms of carbon and energy. Several types of proteins showed enhanced degradation during chilling stress, especially the photosynthetic proteins. Gene expression analysis of 25 different proteins by reverse transcriptase- polymerase chain reaction (RT-PCR) showed that the messenger RNA (mRNA) levels of 18 genes correlated well with the protein levels. In conclusion, our study provides new insights into cold stress responses in tobacco and needs to be further studied in future. Key words : Proteomics, cold stress, tobacco (Nicotiana tabacum).
摘要：
Based on the theory and methods of tourism ecological footprint, from the perspective of the general geomorphology of "Danxia", seven sub-models of tourism ecological footprint had been established which were tourism ecological carrying capacity, transport, water, waste, visiting, entertainment and food. By taking "Danxia" in Hunan Province for example, tourism ecological footprint had been calculated and analyzed. Through researches on ecological profit and loss and nontransferable ecological footprint, the fact that eco-tourism development scale was reasonable or not had been judged. The results showed that ecological deficit was 669.05 hm2 and nontransferable ecological footprint was 1,357.88 hm2. Finally, the paper had proposed countermeasures for eco-tourism sustainable development in "Danxia", hoping to provide reference for the sustainable development of regional tourist ecological economy.
作者机构：
[Cao L.] Key Laboratory of Chinese Materia Medica Modernization, Ministry of Education, Hunan University of Chinese Medicine, Changsha 410208, China;[卢向阳] School of Bioscience and Technology, Hunan Agricultural University, Changsha 410128, China;Key Laboratory of New Drug Research and Development of Chinese Materia Medica, Hunan Academy of Chinese Medicine, Changsha 410013, China;[李顺祥; 黄丹] Key Laboratory of Chinese Materia Medica Modernization, Ministry of Education, Hunan University of Chinese Medicine, Changsha 410208, China, Key Laboratory of New Drug Research and Development of Chinese Materia Medica, Hunan Academy of Chinese Medicine, Changsha 410013, China;[魏宝阳] Key Laboratory of Chinese Materia Medica Modernization, Ministry of Education, Hunan University of Chinese Medicine, Changsha 410208, China, School of Bioscience and Technology, Hunan Agricultural University, Changsha 410128, China
通讯机构：
[Li, S.-X.] K;Key Laboratory of Chinese Materia Medica Modernization, Ministry of Education, Hunan University of Chinese Medicine, China
