Engineered nickel bioaccumulation in Escherichia coli by NikABCDE transporter and metallothionein overexpression

Mine wastewater often contains dissolved metals at concentrations too low to be economically extracted by existing technologies, yet too high for environmental discharge. The most common treatment is chemical precipitation of the dissolved metals using limestone and subsequent disposal of the sludge in tailing impoundments. While it is a cost-effective solution to meet regulatory standards, it represents a lost opportunity. In this study, we engineered Escherichia coli to overexpress its native NikABCDE transporter and a heterologous metallothionein to capture nickel at concentrations in local effluent streams. We found the engineered strain had a 7-fold improvement in the bioaccumulation performance for nickel compared to controls, but also observed a drastic decrease in cell viability due to metabolic burden or inducer (IPTG) toxicity. Growth kinetic analysis revealed the IPTG concentrations used based on past studies lead to growth inhibition, thus delineating future avenues for optimization of the engineered strain and its growth conditions to perform in more complex environments.     

A Wuchiapingian (Late Permian) brachiopod fauna from an exotic block in the Indus–Tsangpo suture zone, southern Tibet, and its palaeobiogeographical and tectonic implications

A brachiopod fauna including 19 species of 17 genera from an exotic block in the Indus–Tsangpo suture zone in southern Tibet is described and illustrated. The brachiopod fauna is dominated by Martinia elegans and two new taxa: Jinomarginifera lhazeensis gen. et sp. nov. and Zhejiangospirifer giganteus sp. nov. The fauna is closely comparable with those from the middle and upper parts of the Wargal Formation and the Chhidru Formation in the Salt Range of Pakistan, the Chitichun Limestone in southern Tibet, and the Basleo area of West Timor, and these correlations suggest a Wuchiapingian age. The fauna exhibits substantial links with both peri–Gondwanan and Cathaysian faunas, which may imply that it is a seamount biota originally located in the southern margin of the Neotethys during the Late Permian, and was later (in the early Cenozoic) displaced and became sandwiched into younger marine deposits in the collision process between India and Eurasia.     

小麦Kr基因在小麦与玉米或鸭茅状摩擦禾杂交中的失活

用３７个小麦（Ｔｒｉｔｉｃｕｍａｅｓｔｉｖｕｍ）品种（系）为母本,分别与黑麦（Ｓｅｃａｌｅｃｅｒｅａｌｅ）、球茎大麦（Ｈｏｒｄｅｕｍｂｕｌｂｏｓｕｍ）、玉米（Ｚｅａｍａｙｓ）和鸭茅状摩擦禾（Ｔｒｉｐｓａｃｕｍｄａｃｔｙｌｏｉｄｅｓ）杂交,比较其亲和性,小麦和玉米或鸭茅状摩擦禾杂交比小麦与黑麦或球茎大麦杂交的亲和性显著提高。携带着显性Ｋｒ１和Ｋｒ２基因的小麦品种Ｈｏｐｅ与黑麦杂交,不能形成胚,而与玉米及鸭茅状摩擦禾杂交时,成胚率分别达１６．００％和３２．５０％。表明控制小麦与黑麦及球茎大麦杂交亲和性的Ｋｒ基因系统在小麦与玉米及小麦与鸭茅状摩擦禾属间杂交中失活。讨论了还存在有其它控制小麦属间杂交亲和性的遗传调控系统的可能性。     

黄瓜幼苗的冷锻炼与低温引起的光抑制

黄瓜幼苗的冷锻炼与低温引起的光抑制李晓萍,陈贻竹,李平,郭俊彦（中国科学院华南植物研究所,广州５１０６５０）关键词：低温引起的光抑制,荧光猝灭,冷锻炼,黄瓜幼苗低温使植物利用光能的能力降低从而引起或加剧光抑制（ｈａｓ等１９８３）。在光抑制中常以叶绿素...     

用快速琼脂糖层析纯化磷酸甘油酸激酶及磷酸甘油醛脱氢酶

研究了用快速琼脂糖离子交换层析(DEAE—Fast Flow sepharose)结台PEG 4000／Reppal PES双水相体系从黄豆中分离纯化磷酸甘油酸激酶(PGK)及磷酸甘油醛脱氢酶(GAPDH)。控制床层高度(10～20cm),径向放大具有压降低的优点．设计多点进料取代传统的中心管进料,解决了径向流场不均匀的问题。GAPr)H的总收率及纯化倍数分别为58％和144,PGK的总收率及纯化倍数分别为41％和44。工艺成本为2．92美元／ku GPADH,具有一定的实用价值。     

中国铜脚异丽金龟组及其分类问题讨论(鞘翅目:丽金龟科)(英)

新设的铜脚异丽金龟组包括中国异丽金龟属已知的大型、绿色种类,绝大多数为常见种,彼此形态十分近似。它们是:铜脚异丽金龟(新纪录)Anomala cupripes Hope new record,红脚异丽金龟(新种)A. rubripes sp. nov., 绿脚异丽金龟(新亚种)A. rubripes virescens ssp. nov., 彤脚异丽金龟(新种)A. ignipes sp. nov., 川直异丽金龟A. truncata Bates,滇直异丽金龟(新等级)A. truncata chlorochelys Arrow, stat, nov., 宽角异丽金龟A. expansa Bates,大绿异丽金龟(新种)A. virens sp. nov., 砂尾异丽金龟(新种)A. granuliformis sp. nov. 和檐角异丽金龟(新种)A. planicorna sp. nov.。其中红脚异丽金龟和绿脚异丽金龟是我国南部和台湾的重要害虫,国内外文献中长期误作铜脚异丽金龟引用至今。     

胁迫处理对林生山黧豆蛋白质多肽及其含量的影响

应用二维电泳技术,分析了经水分胁迫（ＰＥＧ）、盐分胁迫（ＮａＣｌ）和热激（４０℃）处理后林生山黧豆（ＬａｔｈｙｒｕｓｓｙｌｖｅｓｔｒｉｓＬ．）体内蛋白质多肽及其含量的变化。有些蛋白质经ＰＥＧ、ＮａＣｌ和热激处理后可以产生相同的变化。两种不同的胁迫因子对某些蛋白质的影响有一定的共同性。特定的胁迫条件可以造成特定的影响。不同胁迫因子对同一蛋白质多肽可以造成不同的影响。胁迫下蛋白质的变化可能与林生山黧豆抵抗和适应胁迫条件的能力以及体内非蛋白质氨基酸的代谢有关     

萌发花生种子子叶肽链内切酶的纯化和性质

萌发花生种子子叶的肽链内切酶经硫酸铵沉淀,ＳｅｐｈａｄｅｘＧ－１００凝胶层析,ＤＥＡＥ－纤维素２３阴离子交换层析和ＤＥＡＥ－ＳｅｐｈａｄｅｘＡ５０层析,得到纯化的酶,该酶有两条同工酶,分子量分别为５８和５５ＫＤ,Ｋｍ为９．９μｍｏｌ／Ｌ,是半胱氨型肽链内切酶（ＥＣ３．４．２２）,对未萌发花生种子的贮藏蛋白没有明显降解作用．