曝气生物滤池中碳和氮代谢特性

用充填陶瓷滤料的曝气生物滤池研究碳和氮代谢特性.曝气生物滤池进水氨氮为52 mg/L左右、COD为100 mg/L左右和回流比为200%时,经过20多d的运行,出水氨氮小于0.05 mg/L、COD小于25 mg/L、亚硝态氮为4.7 mg/L和硝态氮为7.1 mg/L,COD去除率达75%,氨氮去除率达99.9%,总氮去除率达78%;过大和过小的回流比对曝气生物滤池的运行性能都是不利的.研究成果可以应用于一般城市污水以及含低COD、高氨氮工业废水的处理.     

Isolation and characterization of Sporobolomyces sp. LF1 capable of degradingchlorimuron-ethyl

A yeast strain which was capable of degrading sulfonylurea herbicide chlorimuron-ethyl named as LF1 was isolated from achlorimuron-ethyl contaminated soil near the warehouse of the factory producing chlorimuron-ethyl in Shenyang City, Northeast China.The strain was identified as Sporobolomyces sp., based on its morphological and physiological characteristics and the phylogeneticanalysis of 18S rRNA gene sequence. So far, this is the only yeast strain of Sporobolomyces sp. which is able to degrade chlorimuronethyl.Incubation tests showed that when the initial concentration of chlorimuron-ethyl in culture was 5 mg/L, LF1 could degrade morethan 77% of the herbicide after incubation for 4 d at 30°C. The possible mechanism of chlorimuron-ethyl degradation by LF1 could bethe acidic hydrolysis caused by the acids from the metabolism of the yeast strain. Further study should be conducted to examine thepathways of chlorimuron-ethyl degradation by LF1 and to approach the feasibility of using LF1 to degrade the chlorimuron-ethyl insoil system.     

能量解偶联代谢对剩余污泥的减量化研究

采用3,3′,4′,5四氯水杨酰苯胺(TCS)作为代谢解偶联剂添加到活性污泥工艺中,连续曝气分批培养实验结果表明,TCS以固体方式投加的效果好于液态投加,每天投加12mg,相当于液态浓度1mg/L,可使污泥产量49%。在30d的运行期间,每天分别在4个反应器中添加TCS5.0、8、10和12mg,出水氨氮及总氮浓度均未受影响,但污泥的COD去除能力有所下降,当投加12mg时,COD去除率比对照下降了8.9%。污泥的SVI值有所上升,但沉降性能未见有明显影响。污泥微生物的种群结构发生了改变。     

茂兰保护区小生境土壤微生物活性研究

以茂兰国家级自然保护区内三种植被（原生林、次生林、灌木林）下的土壤为研究对象,探讨了小生境土壤微生物数量、微生物量碳（BC）、微生物量氮（BN）、微生物熵（qSMBC）、基础呼吸及代谢熵（qCO2）的变化特征。结果表明：微生物数量、BC、BN、基础呼吸、qSMBC基本呈现石沟〉土面的趋势,qCO2则表现为土面〉石沟,即...     

城市生活垃圾循环利用系统物质代谢框架的构建

讨论了传统的物质流分析（MFA）方法用于城市生活垃圾代谢分析的适用性及不足之处,在此基础上结合城市生活垃圾的处理流程,对传统的MFA框架进行了改进,构建了适合城市生活垃圾代谢分析的框架,并对新框架的3个模块进行了详细的说明,建立了相应的评价指标体系并给出了应用实例。城市生活垃圾循环利用系统物质代谢分析框架能够清楚地描述生活垃圾进入经济系统后的具体流向和流量,为描述城市生活垃圾的代谢情况提供了定性及定量化的分析工具。     

Listeria monocytogenes batch culture growth response to metabolic inhibitors

In certain environments nutrient and energy sources available to microorganisms can be limited. Foodborne pathogens must efficiently adapt in order to be successfully transmitted through the food chain to their hosts. For the intracellular foodborne pathogen Listeria monocytogenes, little is known regarding its response to nutrient/energy-limiting conditions. The alternative stress responsive sigma factor σ^B has been reported to contribute to survival under specific stresses. Therefore, the effects of several metabolic inhibitors on growth of L. monocytogenes wild-type and a ΔsigB mutant were examined. In the absence of inhibitors, both strains reached stationary phase after 18 h at 23°C and 10 h at 37°C. All of the metabolic inhibitors slowed growth of either strain, with few differences observed among the different inhibitors.     

中国汽车行业钢铁物质流代谢研究

汽车行业在我国发展迅速,汽车行业的钢铁物质流代谢在整个国民经济的钢铁物质流代谢系统中的影响已不可忽视。研究中国汽车行业钢铁物质流代谢对再生资源利用产业、再制造行业的发展具有重要的意义。结合系统动力学方法及相关经验模型对中国汽车行业钢铁物质流代谢进行研究。首先通过Gompertz模型研究了世界主要国家汽车千人保有量与时间的关系,以此为参照设定中国汽车千人保有量随时间变化的相关参数。其次利用中国汽车行业钢铁物质流循环代谢的系统动力学模型,对系统关键流量、存量的动态变化过程进行考察分析,通过设定不同情景、不同寿命分布,研究中国汽车报废量、钢板和零件耗钢量随时间变化的规律,并探讨了零件再制造、汽车轻型化等问题。选取汽车千人保有量为260辆/千人的中等情景进行分析,考察时间为2011-2050年,结果表明报废汽车年折钢量与汽车行业钢材年消耗量比值不断上升,最终可达到1.2;再制造行业潜力巨大,零件再制造数量将近8亿件;延长汽车4 a寿命,可减少近一半的汽车报废量;通过轻型化,钢材年消耗量可减少18%,减少近650万t,累计减少1亿多吨钢材,节省大量资源,经济和环境效益显著。     

生物除磷生化代谢模型的研究进展

阐述了在生物除磷过程中生化代谢模型的建立与发展,分别介绍了早期的Comeau/Wentzel模型和Mino模型,在生物除磷代谢模型发展上有重要意义的Smolder模型和Delft模型,以及目前较被关注的反硝化除磷模型和国际水协(IWA)提出的ASM2和ASM2D模型.从而提出将生物除磷模型同化学除磷模型相结合,与在线监测技术发展融合,并且在模型中加入更多的环境因素将是生化除磷模型的主要发展方向.     

大气颗粒物PM2.5诱导机体损伤相关研究中的代谢组学进展

目前,中国大气污染问题仍然普遍存在,细颗粒物(fine particulate matter 2.5, PM_2.5)是一种空气动力学直径<2.5 μm的大气污染物。其较小的粒径赋予其强大的穿透性,可随血液循环到达全身,可以对多种器官和组织造成损伤,因此,探究PM_2.5的毒理机制尤为重要。代谢组学作为一种分析代谢物变化的方法在许多研究领域中广泛应用,目前关于PM_2.5引起机体代谢物紊乱的相关研究也逐渐得到关注。本文综述了目前PM_2.5相关研究中的代谢组学研究进展,总结了PM_2.5暴露显著影响的机体代谢通路,分别为脂代谢通路、TCA循环(tricarboxylic acid cycle, TCA cycle)代谢通路、氨基酸代谢通路和核苷酸代谢通路,进一步分析了代谢物变化与PM_2.5暴露之间的可能关系,对后续相关的代谢组学研究提出建议和发展方向。     

A new approach to graphical and numerical analysis of links between plant chemotaxonomy and secondary metabolism from HPLC data smoothed by a simplex mixture design

Summary. HPLC analysis of secondary metabolites represents an efficient tool for the studying of plant chemical diversity under different aspects: chemotaxonomy, metabolomics, adaptative responses to ecological factors, etc. Statistical analyses of HPLC databases, e.g. correlation analysis between HPLC peaks, can reliably provide information on the similarity/dissimilarity degrees between the chemical compounds. The similarities, corresponding to positive correlations, can be interpreted in terms of analogies between chemical structures, synchronic metabolisms or co-evolution of two compounds under certain environment conditions, etc. . In terms of metabolism, positive correlations can translate precursor-product relationships between compounds; negative correlations can be indicative of competitive processes between two compounds for a common precursor(s), enzyme(s) or substrate(s). Furthermore, the correlation analysis under a metabolic aspect can help to understand the biochemical origins of an observed polymorphism in a plant species. With the aim of showing this, we present a new approach based on a simplex mixture design, Scheffé matrix, which provides a correlation network making it possible to graphically visualise and to numerically model the metabolic trends between HPLC peaks. The principle of the approach consisted in mixing individual HPLC profiles representative of different phenotypes, then from a complete mixture set, a series of average profiles were calculated to provide a new database with a small variability. Several iterations of the mixture design provided a smoothed final database from which the relationships between the secondary metabolites were graphically and numerically analysed. These relationships were scale-dependent, namely either deterministic or systematic: the first consisted of a monotonic global trend covering the whole variation field of each metabolites’ pair; the second consisted of repetitive monotonic variations which gradually attenuated or intensified along a global trend. This new metabolomic approach was illustrated from 404 individual plants of Astragalus caprinus (Leguminoseae), belonging to four chemical phenotypes (chemotypes) on the basis of flavonoids analysed in their leaves. After smoothing, the relationships between flavonoids were numerically fitted using linear or polynomial models; therefore the co-response coefficients were easily interpreted in terms of metabolic affinities or competitions between flavonoids which would be responsible of the observed chemical polymorphism (the four chemotypes). The statistical validation of the approach was carried out by comparing Pearson correlations to Spearman correlations calculated from the smoothed and the crude HPLC database, respectively. Moreover, the signs of the smoothed relationships were finely supported by analogies and differences between the chemical structures of flavonoids, leading to fluent interpretation in relation to the pathway architecture.