不同基模势下luxAB标记的弗氏中华根瘤菌在土壤中的存活能力

经接合转移将luxAB基因插入弗氏中华根瘤菌（Rhizobium fredii)染色体,取可高效结瘤固氮的R fredii lux3菌株用于分子生态学研究,在不同基模势下,研究了lux3在土壤中的存活,基模势为－30和－750kPa时,lux3在灭菌土中的存活能力明显（P＜0．05）高于未灭菌土,当基模势为－1500kPa时,土壤是否灭菌对lux3的存活影响没有差异,不同基模势对lux3活性影响显著,在－1500kPa的未灭菌土中随着饥饿时间的延长,可恢复活性的细菌数量显著下降,比较了测定微生物活性的3种方法（即脱氢酶活性,生物发光和微生物呼吸）,发光值变化与活细胞密度变化一致。     

黑曲霉(ASPERGILLUS NIGER)SG株三磷酸甘油醛脱氢酶基因的分离与初步鉴定

黑曲霉（Ａｓｐｅｒｇｉｌｕｓｎｉｇｅｒ）在工业生产和科学研究中占有重要地位,因为许多黑曲霉菌株能产生有机酸和酶制剂,并能分泌大量蛋白质到细胞外［１,６］．三磷酸甘油醛脱氢酶（Ｇｌｙｃｅｒａｌｄｅｈｙｄｅ３ｐｈｏｓｐｈａｔｅｄｅｈｙｄｒｏｇｅｎａ...     

中国“十三五”时期省际碳减排目标的效率分配

首先,将"零和收益"的博弈思想引入到SBM模型中,构建了基于零和收益的碳减排SBM效率分配模型(ZSG-SBM)。然后,基于"十三五"规划中我国整体碳强度降低18%的减排约束,从经济增速和能源消费结构2个维度设置了"十三五"期间我国经济系统的4种发展情景,应用上述ZSG-SBM模型对碳减排目标进行了省际层面的效率分配。并通过对比各省经济发展现状和碳减排目标的分配结果,分析了各省的低碳经济发展路径。结果表明:采用ZSG-SBM模型对碳排放量进行效率分配后,30个省份的投入、产出指标实现了有效配置,碳排放效率到达效率前沿。政府基于"公平"导向的行政分配方案会造成一定程度的效率损失,基于ZSG-SBM模型的效率分配方案更符合低碳经济的长远发展要求。在碳强度约束的基础上,能源强度的再约束将迫使各省优化能源消费结构,从而提升我国整体碳排放效率。"十三五"时期,我国有16个省份的碳减排目标分配结果大于18%的平均标准,各省应根据自身资源禀赋、经济水平、产业结构和能源消费结构的现状选择差异的低碳经济发展道路。     

氨态氮对菲律宾蛤仔毒理机制研究的内参基因筛选

为了准确和系统地分析NH_3-N对菲律宾蛤仔(Ruditapes philippinarum)毒性的分子机制,并对相关基因的转录组学数据进行验证,利用ge Norm和Normfinder这2种软件,以暴露30 d中不同时间点的鳃组织c DNA为模板,从18S r RNA(18S)、beta-actin(Actin)、beta-tubulin(Tubu)、elongation factor 1-alpha(EF1α)、cyclophilin A(Cy PA)、Ubiquitin(Ub)等6个备选管家基因中,筛选可以稳定表达的内参基因,作为转录组学分析的内参基因。以稀释50倍的鳃组织c DNA模板作为检测模板,ge Norm软件分析获得6对备选内参基因的表达稳定性依次为:EF1αCy PAActinTubuUb18S,较优内参为EF1α和Cy PA;Norm Finder软件分析获得6对备选内参基因的表达稳定性为:EF1αActinTubuCy PAUb18S,最优内参基因为EF1α。为了验证上述筛选结果,分别以EF1α和Cy PA作为内参基因研究unigene1的表达趋势,发现以EF1α为内参基因时,unigene1的q RT-PCR的表达趋势与其转录组表达倍数的变化趋势一致。因此确定NH_3-N暴露菲律宾蛤仔后,鳃组织中表达最为稳定的内参基因为EF1α。     

Long-term dynamics of the atrazine mineralization potential in surface and subsurface soil in an agricultural field as a response to atrazine applications

The dynamics of the atrazine mineralization potential in agricultural soil was studied in two soil layers (topsoil and at 35-45 cm depth) in a 3 years field trial to examine the long term response of atrazine mineralizing soil populations to atrazine application and intermittent periods without atrazine and the effect of manure treatment on those processes. In topsoil samples, ¹⁴C-atrazine mineralization lag times decreased after atrazine application and increased with increasing time after atrazine application, suggesting that atrazine application resulted into the proliferation of atrazine mineralizing microbial populations which decayed when atrazine application stopped. Decay rates appeared however much slower than growth rates. Atrazine application also resulted into the increase of the atrazine mineralization potential in deeper layers which was explained by the growth on leached atrazine as measured in soil leachates recovered from that depth. However, no decay was observed during intermittent periods without atrazine application in the deeper soil layer. atzA and trzN gene quantification confirmed partly the growth and decay of the atrazine degrading populations in the soil and suggested that especially trzN bearing populations are the dominant atrazine degrading populations in both topsoil and deeper soil. Manure treatment only improved the atrazine mineralization rate in deeper soil layers. Our results point to the importance of the atrazine application history on a field and suggests that the long term survival of atrazine degrading populations after atrazine application enables them to rapidly proliferate once atrazine is again applied.     

The politics of climate change policy design in Korea

The climate change policy design of the Lee Myung-bak administration was the outcome of interest group politics around the greenhouse gas and energy target management scheme, carbon taxes, and the emission-trading scheme. Using qualitative methods, this research examines powerful stakeholders and their interests at play in Korea’s climate change policymaking processes. It also links the political economy of climate change policy to the legacy of the ‘developmental state’ and examines environmental developmentalism in the design of the three climate change policies. The Lee administration strongly promoted environmental developmentalism, which created a new growth engine in an environmental field, while bolstering manufacturing businesses and excluding the views of environmental non-governmental organisations from the target-management and the emission-trading schemes. The Lee administration also sought to facilitate pro-business measures such as low taxes, which led it to reject a carbon tax. Therefore, environmental developmentalism was central to the politics of the Lee administration’s climate change policy design.     

Cow excrements enhance the occurrence of tetracycline resistance genes in soil regardless of their oxytetracycline content

Fertilizing soils with animal excrements from farms with common antibiotic use represents a risk of disseminating antibiotic resistance genes into the environment. In the case of tetracycline antibiotics, it is not clear, however, whether the presence of antibiotic residues further enhances the gene occurrence in manured soils. We established a microcosm experiment in which 3 farm soils that had no recent history of fertilization with animal excrements were amended on a weekly basis (9 times) with excrements from either an oxytetracycline-treated or an untreated cow. Throughout the study, the concentration of oxytetracycline in excrements from the treated cow was above 500 μg g⁻¹ dw, whereas no oxytetracycline was detected in excrements from the healthy cow. Both excrements contained tetracycline resistance (TC-r) genes tet(L), tet(M), tet(V), tet(Z), tet(Q) and tet(W). The excrements from the treated cow also contained the tet(B) gene, and a higher abundance of tet(Z), tet(Q) and tet(W). Three weeks after the last excrement addition, the individual TC-r genes differed in their persistence in soil: tet(Q) and tet(B) were not detectable while tet(L), tet(M), tet(Z) and tet(W) were found in all 3 soils. There were, however, no significant differences in the total number, nor in the abundance, of TC-r genes between soil samples amended with each excrement type. The oxytetracycline-rich and the oxytetracycline-free excrement therefore contributed equally to the increase of tetracycline resistome in soil. Our results indicate that other mechanisms than OTC-selection pressure may be involved in the maintenance of TC-r genes in manured soils.     

2℃和1.5℃目标对中国国家自主贡献和长期排放路径的影响

在《巴黎协定》设置的混合减排机制下,中国的INDC尽管自主提出,但也受全球气候目标及全球减排进展的影响。本文基于气候公平的不同原则,建立了公平分配未来碳排放空间的综合性框架,并利用最新情景研究数据,分析了2℃和1.5℃目标对中国INDC力度以及长期排放路径的影响。研究结果表明:第一,相比2℃目标,1.5℃目标对本世纪内全球累积碳排放空间、关键时点的减排目标、近期减排力度以及碳中和时间等都提出了更高要求。第二,根据公平分配方案的评估结果表明,2℃目标下,中国现有INDC在责任方案下能够满足减排要求,而在其他方案下存在排放差距。而在1.5℃目标下,中国在四个方案下均无法满足减排要求,且排放差距进一步扩大。第三,2℃和1.5℃目标对中国确定长期排放目标以及碳中和时间,也会产生显著影响。相比2℃目标,1.5℃目标下,中国2050年排放相对2010年下降率需要再增加约15个百分点,实现碳中和的时间需要提前15年左右。因此,中国需要根据公平分配研究给出的提高INDC力度要求的区间,提前准备《巴黎协定》后关于全球盘点和INDC更新议题新一轮谈判的应对策略,同时应尽早启动制定长期低碳发展战略的政策研究进程。     

山地城市污水特细砂除砂系统目标粒径确定

三峡库区重庆段污水处理厂长期受污水特细砂影响;污水中特细砂平均粒径仅182.6μm,而传统沉砂池通常以粒径大于200μm砂粒去除率来衡量沉砂池除砂效果;参考国外传统除砂设备性能参数估算特细砂总去除率仅为51.2%,若考虑砂水分离器效率等因素,则实际去除率更低。基于重庆"特细砂"的粒径分布特征、除砂效率理论计算分析认为,特细砂除砂装置的设计研发时,除砂粒径分界点或目标粒径为100μm,并以粒径≥100μm细砂去除率来衡量沉砂池的除砂效果,能保证粒径分布曲线中70%~95%的特细砂得到有效去除,能满足污水处理厂对特细砂的去除要求。     

微氧折流反应器中产甲烷菌的分布与群落结构分析

为了研究微氧条件下折流反应器处理生活污水的微生物学机理,针对产甲烷菌的MCR基因采用实时荧光定量PCR和构建克隆文库的方法,对反应器中的关键功能微生物产甲烷菌的分布特点与群落结构变化进行了分析。结果表明,微氧条件下折流反应器的环境条件可以保证产甲烷菌的增长,不同格室的产甲烷菌丰度均要高于接种污泥(1 720 copies/ng),其中经过微氧曝气处理的1#(2 864 copies/ng)和2#(2 282 copies/ng)格室产甲烷菌丰度低于厌氧状态的3#(3 508copies/ng)格室;微氧处理后折流反应器产甲烷菌的群落结构发生了明显的变化,接种污泥的产甲烷菌多属于Methanomicrobiales目的 Methanoregulaceae属(6/9),而保持微氧状态的1#格室中产甲烷菌多隶属于Methanomicrobiales目(6/10)的其他类群,2#格室的产甲烷菌则多隶属于Methanobacteriales目(5/10),保持厌氧状态的3#格室的产甲烷菌主要属于Methanomicrobiales目(3/10)和Methanosarcinales目(3/10);产甲烷菌MCR基因的多样性指数表明微氧曝气的引入降低了活性污泥中产甲烷菌的生物多样性。