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251.
微生物燃料电池(microbial fuel cell,MFC)阳极微生物的种类和作用机制对MFC的产电性能有着重要的影响.从已稳定运行1 a的MFC的阳极室分离得到1株电化学活性革兰氏阴性细菌——菌株RE7,其16S rRNA基因序列与Pseudomonas aeruginosa strain CMG 587有99%同源性,属于假单胞菌属(Pseudomonas sp.).利用菌株RE7构建的MFC的稳定产电和循环伏安曲线测定结果都表明,菌株RE7具有较强的电化学活性,利用菌株RE7构建的MFC的最大输出电压为352 mV,相应的最大面积功率密度为69.2 mW/m2,体积最大功率密度为6.2 W/m3.由不同稀释比例的MFC排出液的产电效果比较可知,菌株RE7极有可能是通过自身分泌的氧化还原类物质进行电子传递.  相似文献   
252.
选用大鼠肝匀浆(S9)和鼠肝癌细胞(H4ⅡE)两种体系代谢活化多溴代联苯醚混标(BDEs)和十溴联苯醚(BDE209),采用重组甲状腺激素受体基因酵母检测BDEs和BDE209母体及其代谢产物的类/抗甲状腺激素效应.结果表明,BDEs和BDE209母体均不表现甲状腺激素效应(p>0.05);但是经S9和H4ⅡE细胞代谢活化后,其代谢产物表现出明显的类甲状腺激素活性和抗甲状腺激素活性(p<0.05),BDEs和BDE209的干扰甲状腺激素效应需要经过代谢活化步骤.比较不同代谢活化体系,重组酵母细胞本身的代谢活化作用并不显著,而H4ⅡE细胞和S9代谢活化体系均能够导致活性中间体.  相似文献   
253.
糖外排转运蛋白(sugars will eventually be exported transporters,SWEET)介导植物光合同化产物蔗糖的跨膜运输.以橄榄(Canarium album(Lour.)Raeusch.)果实为材料,通过气相色谱串联质谱(GC-MS)检测橄榄果实中糖组分及含量变化,利用RT-PCR技术克隆得到CaSWEET7和CaSWEET15基因开放阅读框(ORF)序列.结果表明:CaSWEET7和CaSWEET15基因ORF全长分别为774 bp和951 bp,分别编码长度为257个和316个氨基酸残基,具有2个MtN3_slv结构域;进化树分析表明,CaSWEET7属于CladeⅡ,CaSWEET15属于CladeⅢ.实时荧光定量PCR(qRT-PCR)技术检测其在不同发育时期的果实中相对表达量变化,结果表明,随着果实发育,CaSWEET7和CaSWEET15表达量逐渐递增,且与果实发育蔗糖含量变化呈显著正相关(相关性系数分别为0.931和0.904,P<0.05);利用酵母功能互补证明CaSWEET7和CaSWEET15基因编码的蛋白具有转运蔗糖能力.本研究表明CaSWEET7和CaSWEET15基因可能在橄榄果实蔗糖积累中发挥作用.(图9表2参44)  相似文献   
254.
GOAL, SCOPE AND BACKGROUND: Lake Shkodra/Skadar is the largest lake in the Balkans region and located on the border between Albania to the south and Montenegro to the north. Because of the wide range of endemic, rare or endangered plant and animal species it supports, Lake Shkodra/Skadar and its extensive associated wetlands are internationally recognised as a site of significance and importance (Ramsar site). In recent years, social and economic changes in both Albania and Montenegro have lead to unprecedented levels of urban and industrial effluent entering the lake. Of particular concern is the increasing input of toxic hydrophobic organic pollutants (HOPs) into the lake and the degree to which these compounds are available for uptake by aquatic biota. Semipermeable membrane devices (SPMDs) have been shown to sample the readily bioavailable fraction (dissolved phase) of waterborne HOPs and in doing so provide relevant data for exposure assessment. The aim of the current study was to use SPMD-based sampling in conjunction with appropriate bioassays and chemical analysis to identify readily bioavailable HOPs in the lake. METHODS: SPMDs were constructed and deployed at three sites in the Albanian sector and three sites in the Montenegrin sector of Lake Skadar/Shkodra for 21 days. Following the dialytic recovery of target analytes and size exclusion chromatographic clean-up, aliquots of SPMD samples were subjected to GC-MS scan analysis for major components, GC-MS SIM analysis for 16 priority pollutant polycyclic aromatic hydrocarbons (PP-PAHs) and assayed for EROD-inducing, estrogenic and mutagenic potential using rainbow trout liver cells (RTL-W1), the yeast estrogen screen (YES) and the Ames Test, respectively. RESULTS AND DISCUSSION: A total of 39 compounds were tentatively identified in SPMD samples from the six sampling sites. Alkylated PAHs were the most abundant and ubiquitous compounds present along with various sterols and sterol derivatives. Numerous other compounds remain unidentified. 15 of the 16 targeted PP-PAHs were present in samples from one or more of the sampling sites indicating these compounds are both readily bioavailable and widely distributed in Lake Shkodra/Skadar. Total PP-PAH concentrations ranged between 3991 ng/SPMD and 10695 ng/SPMD. Bioassays carried out on SPMD samples revealed significant EROD-inducing and estrogenic potential at five of the six sampling sites indicating toxicologically relevant compounds are readily available for uptake by resident aquatic biota. EROD-inducing potential was positively correlated with targeted PP-PAH concentration (r2 = 0.74). However, comparison of bioassay- and analytically-derived toxicity equivalents revealed targeted PP-PAHs were responsible for less than 0.06% of the total EROD-inducing potential. CONCLUSIONS AND OUTLOOK: The combination of SPMD-based sampling with appropriate bioassays and chemical analysis provided an effective tool for the identification of environmentally relevant waterborne pollutants in Lake Shkodra/Skadar. Our results show that toxicologically relevant HOPs including EROD-inducing and potentially estrogenic compounds are widely distributed in the lake and readily available for uptake by aquatic biota. Our results also suggest that alkylated PAHs rather than parent compounds may be of greater toxicological relevance in the lake. As anthropogenic influences continue to increase, SPMD-based sampling is expected to play a central role in future research concerned with the identification, monitoring and assessment of the risk posed by HOPs to Lake Shkodra/Skadar's aquatic biota.  相似文献   
255.
啤酒废酵母的综合利用   总被引:6,自引:0,他引:6  
阚久方  张华 《环境科技》2001,14(3):9-10
啤酒废酵母含有丰富的营养物质,许多啤酒厂并没有充分利用,而是作为废弃物排入啤酒废水,增加了啤酒废水的处理负荷和难度。针对这种情况,我们利用本厂啤酒废酵母进行了生产酵母抽提物及营养酱油的研究,取得了满意的效果。不仅获得了优质产品,而且大大降低了啤酒酵母的污染负荷。  相似文献   
256.
A high resolution technique was applied to amniotic fluid cells by synchronization. After inoculation, the cells were incubated for 30 h in the presence of either thymidine or 5-bromodeoxyuridine (BrdU). After removal of the blocking agent and addition of a low concentration of thymidine, the cells were incubated for another 6 1/2–7 h, then harvested in prometaphase without colcemid. This technique gives a mitotic index of 3·7 per cent after thymidine synchronization and of 3·2 per cent after BrdU synchronization, and more than half of the mitoses were in the earlier phases with the chromosomes showing more than 550 bands per haploid set. GBG, GTG, and RHG prometaphases are presented. Precise high-resolution banding of chromosomes of amniotic fluid cells can increase diagnostic accuracy.  相似文献   
257.
固定化细胞处理废水的关键性包埋技术条件研究   总被引:9,自引:0,他引:9  
研究了以聚乙烯醇为主要包埋材料的混合载体,固定化细胞处理有机废水的关键性包埋技术条件,解决了妨碍固定化细胞在废水处理领域推广应用所的制备成球难,活性丧失大、易破碎、发胀粘连上浮等问题。  相似文献   
258.
啤酒酵母吸附去除水中Cr(Ⅵ)的研究   总被引:3,自引:1,他引:3  
研究了吸附剂用量、重金属初始浓度、pH对非活性啤酒酵母菌体吸附Cr(Ⅵ)的影响.结果表明,吸附剂的用量越高,对Cr(Ⅵ)的去除率也越高,但单位菌体吸附量却越低;相反,Cr(Ⅵ)初始浓度越高,对Cr(Ⅵ)的去除率就越低,但单位菌体吸附量却越高;溶液的pH也是影响吸附去除效果的重要因素之一,当pH为1时,吸附去除效果最好,非活性啤酒酵母菌体对Cr(Ⅵ)的吸附过程可用Langmuir和Freundlich等温吸附模型来拟合,但Langmuir等温吸附模型的拟合效果更好,由Langmuir等温吸附方程得到最大吸附量为9.17mg/g干菌体.  相似文献   
259.
Pesticides are a well-known family of chemicals that have contaminated water systems globally. Four common subfamilies of pesticides include organochlorines, organophosphates, pyrethroids, and carbamate insecticides which have been shown to adversely affect the human nervous system. Studies have shown a link between pesticide exposure and decreased viability, proliferation, migration, and differentiation of murine neural stem cells. Besides human exposure directly through water systems, additional factors such as pesticide bioaccumulation, biomagnification and potential synergism due to co-exposure to other environmental contaminants must be considered. A possible avenue to investigate the molecular mechanisms and biomolecules impacted by the various classes of pesticides includes the field of -omics. Discovery of the precise molecular mechanisms behind pesticide-mediated neurodegenerative disorders may facilitate development of targeted therapeutics. Likewise, discovery of pesticide biodegradation pathways may enable novel approaches for water system bioremediation using genetically engineered microorganisms. In this mini-review, we discuss recently established harmful impacts of various categories of pesticides on the nervous system and the application of -omics field for discovery, validation, and mitigation of pesticide neurotoxicity.  相似文献   
260.
王娟  张遵真  张浩  李娜  车望军 《环境科学学报》2005,25(12):1698-1701
采用重组酵母测评系统对香烟烟雾溶液和汽车尾气提取物分别进行雌激素活性的测定.结果显示在受试浓度下,PBS烟雾溶液和DMSO烟雾溶液的β-半乳糖苷酶活性与溶剂对照相比均无显著性差异(P>0·05).汽油燃料车尾气在600mL·mL-1时,其酵母菌液OD600明显低于DMSO对照组(P<0·05);在150mL·mL-1剂量时,汽油燃料车尾气所检出的β-半乳糖苷酶活性为44·56,与DMSO对照组相比有显著性差异(P<0·05),当剂量增加至300mL·mL-1,酶活性升高为66·43,约为对照组的12倍,其它各剂量组酶活性与DMSO对照组相比无显著性差异(P>0·05);甲醇燃料车尾气的β-半乳糖苷酶活性与溶剂对照相比无显著性差异(P>0·05).提示汽油燃料车尾气具有弱雌激素活性,甲醇燃料车尾气和香烟烟雾溶液未检出雌激素活性.  相似文献   
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