营养物质对细菌质粒pEA9：：Km在土壤中拼命转移频率的影响

用成团肠杆菌（Ｅｍｔｅｒｏｂａｃｔｅｒ ａｇｇｌｏｍｅｒａｎｓ）Ｔ７（ｐＥＡ９：：Ｋｍ）为供体菌,以Ｅ．ａ．３３９（ｐＥＡ９＾－）为受体菌在天然土壤中进行接合实验,测定各种营养物质对重组质粒ｐＥＡ９：：Ｋｍ同源接合转移频率的影响。实验发现,如果在土壤中加入生理盐水或无机盐培养基,就观察不到细菌数量的增加和质粒的转移;只有加入碳源物质后才检测到细菌数量的增加和质粒的接合转移,接合转移频率的大小位于１     

南方某水厂处理工艺过程中内分泌干扰物的变化规律

对南方某水厂处理工艺过程中内分泌干扰效应进行了研究.将水源水和各处理工艺的出水用固相萃取方法富集后,按不同极性洗脱,得到从非极性到极性3个组分,对总提取物和各分级富集组分分别进行重组基因酵母检测.探讨了该水厂不同处理工艺过程中内分泌干扰物的变化规律.结果表明:水源水中该类污染物浓度最高,相当于0.25 pmol/L雌二醇当量,主要存在于非极性组分(正己烷洗脱组分)中.各处理工艺段水样都存在一定程度的内分泌干扰物效应.经处理后,非极性组分内分泌干扰物效应降低,极性组分内分泌干扰物效应逐渐增加,但总地内分泌干扰物效应逐渐递减,现有工艺对雌激素类物质有较好的去除效果,去除率达到83%.研究表明,重组基因酵母检测技术结合水样的固相萃取、三步纯化分级前处理方法可以快速、有效地筛选和定量分析水样中未知内分泌干扰物及其总体效应.     

Characteristics for the hybrid cell Foaz obtained from the protoplast fusion between yeast and photosynthetic bacteria in soybean processing wastewater

The optimal pH and temperature, maximum specific degradation rate, half rate constant and flocculation rate for the hybrid cell Foaz were measured in the reaction for the degradation of soybean processing wastewater(SPW) in this study. The optimal pH and temperature for Foaz in SPW were the same as those of its parental strains Saccharomyces cerevisiae Y9407 and Rhodobacter sphaeroides P9479, but the flocculation rate, the maximum specific degradation rate and the half rate constant for Foaz were higher than those of its parental strains. The results suggest that the characteristics of the inter-kingdom fusant Foaz constructed from the protoplast fusion between the eukaryote cell yeast S.cerevisiae and the prokaryote cell photosynthetic bacteria R.Sphaeroides may favor degrading organic pollutant in SPW and removing biomass from the effluent.     

Managing Water to Protect Fish: A Review of California’s Environmental Water Account, 2001–2005

The Sacramento-San Joaquin Delta, the landward reach of the San Francisco Estuary, provides habitat for threatened delta smelt, endangered winter-run Chinook salmon, and other species of concern. It is also the location of huge freshwater diversion facilities that entrain large numbers of fish. Reducing the entrainment of listed fishes into these facilities has required curtailment of pumping, reducing the reliability of water deliveries. We reviewed the first 5 years (2001–2005) of the Environmental Water Account (EWA), a program instituted to resolve conflicts between protecting listed fishes and providing a reliable water supply. The EWA provided fishery agencies with control over 0.2–0.4 km³ of water to be used for fish protection at no cost to users of exported water, and fish agencies guaranteed no disruption of water supply for fish protection. The EWA was successful in reducing uncertainty in water supply; however, its contribution to the recovery of listed fishes was unclear. We estimated the effectiveness of the EWA to be modest, increasing the survival of winter-run Chinook salmon by 0–6% (dependent on prescreen mortality), adult delta smelt by 0–1%, and juvenile delta smelt by 2–4%. Allocating EWA water for a single life stage of one species could provide larger gains in survival. An optimally allocated EWA of equal size to the median of the first 5 years could increase abundance of juvenile delta smelt up to 7% in the springs of dry years. If the EWA is to become a long-term program, estimates of efficacy should be refined. If the program is to be held accountable for quantitative increases in fish populations, it will be necessary to integrate scientific, possibly experimental, approaches.     

Production of Ethanol by an Integrated Valorization of Olive Oil Byproducts. The Role of Phenolic Inhibition (2 pp)

Background, Aim and Scope Agricultural industrial wastes can frequently be used as raw materials in the production of bio-fuels. Olive-oil milling wastewater is considered as one of the most polluting agro-industrial residues, but fortunately due to its high content of organic matter, it has the potential to be a valuable starting material to obtain bio-ethanol via fermentation with Saccharomyces cerevisiae. The fermentation of olive-oil milling wastewater has been demonstrated with good yield of ethanol (8-12%v/v) once the level of reducing sugars is appropriate and the phenolic fraction, which inhibits the yeast, is removed. Materials and Methods: - Results: - Discussion: - Conclusions: - Recommendations and Perspectives: -     

Contaminant exposure in outmigrant juvenile salmon from Pacific Northwest estuaries of the United States

To better understand the dynamics of contaminant uptake in outmigrant juvenile salmon in the Pacific Northwest, concentrations of polychlorinated biphenyls (PCBs), DDTs, polycylic aromatic hydrocarbons (PAHs) and organochlorine pesticides were measured in tissues and prey of juvenile chinook and coho salmon from several estuaries and hatcheries in the US Pacific Northwest. PCBs, DDTs, and PAHs were found in tissues (whole bodies or bile) and stomach contents of chinook and coho salmon sampled from all estuaries, as well as in chinook salmon from hatcheries. Organochlorine pesticides were detected less frequently. Of the two species sampled, chinook salmon had the highest whole body contaminant concentrations, typically 2--5 times higher than coho salmon from the same sites. In comparison to estuarine chinook salmon, body burdens of PCBs and DDTs in hatchery chinook were relatively high, in part because of the high lipid content of the hatchery fish. Concentrations of PCBs were highest in chinook salmon from the Duwamish Estuary, the Columbia River and Yaquina Bay, exceeding the NOAA Fisheries' estimated threshold for adverse health effects of 2400 ng/g lipid. Concentrations of DDTs were especially high in juvenile chinook salmon from the Columbia River and Nisqually Estuary; concentrations of PAH metabolites in bile were highest in chinook salmon from the Duwamish Estuary and Grays Harbor. Juvenile chinook salmon are likely absorbing some contaminants during estuarine residence through their prey, as PCBs, PAHs, and DDTs were consistently present in stomach contents, at concentrations significantly correlated with contaminant body burdens in fish from the same sites.     

顺丁烯二酸异构酶工程菌发酵条件优化

为提高重组大肠杆菌中顺丁烯二酸异构酶表达量,通过正交试验设计,对工程菌的生长条件和目的蛋白可溶表达条件进行优化.采用250 mL三角瓶中装有50 mL(Amp 100 mg L-1)的培养基,分别研究培养基中葡萄糖、蛋白胨、酵母浸粉的浓度,培养基pH值以及摇床转速、装液量、接种量等对蛋白可溶表达量的影响.确定顺丁烯二酸异构酶工程菌最优化培养基为:蛋白胨20 g L-1、酵母浸粉2.5 g L-1、K2HPO4·3H2O 3.0 g L-1、KH2PO4 1.5 g L-1、NaCl 6 g L-1、MgSO43 g L-1,培养基pH调至6.5.确定顺丁烯二酸异构酶工程菌可溶性表达最优条件为:37℃下培养至D600 nm值为1.0时,添加终浓度为0.05 mmol L-1的IPTG进行诱导,诱导温度37℃,摇床转速220 r min-1,装液量20%,接种量5%,诱导时长为6 h.利用BioFlo 415发酵罐以最优化的培养基和发酵条件对该工程菌进行了3批发酵实验,与摇瓶实验相比,顺丁烯二酸异构酶的表达量提高了近1.5倍,单位发酵液的酶活力由46 U mL-1发酵液提高到78 U mL-1发酵液.以上数据为顺丁烯二酸异构酶重组工程菌的中试发酵奠定了基础.图7表2参17     

全氟辛酸对酿酒酵母细胞毒性作用

全氟辛酸(PFOA)广泛应用于工业生产中,具有高度的生物毒性及生物蓄积性,然而PFOA对环境微生物的毒性影响仍有待深入开展.通过流式细胞术测定了酵母菌在不同浓度PFOA胁迫下细胞膜通透性、ROS、线粒体跨膜电位的变化,并且测定了MDA含量和Na+K+-ATPase、Ca2+Mg2+-ATPase活性变化.结果显示PFOA可使PI染色细胞比例增高,酿酒酵母细胞膜通透性增大、ROS和MDA含量升高、线粒体跨膜电位降低,且ROS含量、MDA含量与线粒体跨膜电位降幅均与PFOA胁迫浓度和时间呈正相关.Na+K+-ATPase、Ca2+Mg2+-ATPase活性先上升后降低,表明酿酒酵母在PFOA胁迫下,其生理活性受到抑制甚至发生细胞凋亡.证明PFOA对酿酒酵母具有生物毒性,100 mg·L-1PFOA对酿酒酵母具有即时毒性.该结果可为PFOA的影响评价提供更多依据.     

Urban airborne particulate: genotoxicity evaluation of different size fractions by mutagenesis tests on microorganisms and comet assay

The genotoxic effects of different size fractions of airborne particulate (Total, PM₁₀ and PM_2.5), extracted with acetone or toluene, were evaluated by: the Ames plate test (TA98 and TA100 strains, w/o S9), gene conversion and reversion (w/o endogenous metabolic activation) in the Saccharomyces cerevisiae D7 strain, and the comet assay on human leukocytes. The data on human leukocytes confirm the sensitivity of the comet assay and its applicability to assess genotoxicity in environmental samples. The PM_2.5 fraction of airborne particulate generally shows the highest concentration of DNA-damaging compounds. Genotoxic response, in all the test systems applied, is highly dependent on extraction solvent used. Acetone seems to extract compounds with more similar genotoxic responses in the three test systems used than toluene extracts. Toluene appears to extract air pollutants genotoxic on yeast and leukocytes but is mainly cytotoxic on Salmonella.