Anaerobic biodegradation of trimethoprim with sulfate as an electron acceptor

Anaerobic biodegradation of trimethoprim (TMP) coupled with sulfate reduction. Demethylation of TMP is the first step in the acclimated microbial consortia. The potential degraders and fermenters were enriched in the acclimated consortia. Activated sludge and river sediment had similar core microbiomes. Trimethoprim (TMP) is an antibiotic frequently detected in various environments. Microorganisms are the main drivers of emerging antibiotic contaminant degradation in the environment. However, the feasibility and stability of the anaerobic biodegradation of TMP with sulfate as an electron acceptor remain poorly understood. Here, TMP-degrading microbial consortia were successfully enriched from municipal activated sludge (AS) and river sediment (RS) as the initial inoculums. The acclimated consortia were capable of transforming TMP through demethylation, and the hydroxyl-substituted demethylated product (4-desmethyl-TMP) was further degraded. The biodegradation of TMP followed a 3-parameter sigmoid kinetic model. The potential degraders (Acetobacterium, Desulfovibrio, Desulfobulbus, and unidentified Peptococcaceae) and fermenters (Lentimicrobium and Petrimonas) were significantly enriched in the acclimated consortia. The AS- and RS-acclimated TMP-degrading consortia had similar core microbiomes. The anaerobic biodegradation of TMP could be coupled with sulfate respiration, which gives new insights into the antibiotic fate in real environments and provides a new route for the bioremediation of antibiotic-contaminated environments.     

台湾海峡7.3级强震前的热红外增温异常

描述了１９９４年９月１６日台湾海峡７．３级地震前，在震中区附近上空观测到大面积的突发性增温异常带。并对该异常带的形成机理作了探索。     

中国长城沿线生态脆弱性分析及生态保护对策

中国长城沿线是半湿润—半干旱和半干旱—干旱气候的过渡地带,也是农牧业的交错地带,生态极其脆弱,生态压力又大,容易发生生态破坏,而且很难恢复。为了保护中国长城沿线的生态环境,必须调整产业结构,合理布局,采用先进技术,加大投入,提高生态意识,加强法制建设。     

崇明岛区域绿地景观格局优化与分析

以上海市崇明岛为例,基于渗透理论,借助GIS空间分析方法,通过生态适宜性、生态敏感性及社会经济可行性三方面的分析,对崇明岛土地利用现状及规划2种情景下的绿地格局进行优化分析,并提出了不同情景下的岛区优先绿化区、绿化区和补充绿化区,对崇明岛未来绿化及生态岛建设具有重要的理论和实践指导意义.其中,状况较好的优先绿化区、绿化区和补充绿化区面积在规划后都有不同程度的增长,特别是补充绿化区增长幅度较大.而绿地可行性稍差的加强管理区和维持原状区较现状都有一定减少.     

Eperimental study of photooxidation products of ethylbenzene

Smog chamber experiments were performed to investigate the composition of products formed from photooxidation of aromatic hydrocarbon ethylbenzene.Vacuum ultraviolet photoionization mass spectrometer and aerosol time-of-flight mass spectrometer were used to measure the products in the gas and particle phases in real-time.Experimental results demonstrated that ethylphenol,methylglyoxal,phenol,benzaldehyde,and 2-ethylfurane were the predominant photooxidation products in both the gas and particle phases.However,there were some differences between detected gas phase products and those of particle phase,for example,2-ethylfurane,ethylglyoxylie acid,nitroethylbenzene,3,4-dioxopentanal and ethyl-nitrophenol were only existing in the particle-phase.The possible reaction mechanisms leading to these products were also discussed and proposed.     

Application of stimulating agents on the immobilized bioluminescence strain Pseudomonas putida mt-2 KG1206, preserved by deep-freezing, for the convenient biomonitoring

This study was conducted to develop methods for the application of an immobilized bioluminescence strain(KG1206),preserved by deep-freezing(DF),for the monitoring of contaminated environments.The immobilized cells,preserved by DF,required approximately 2 hr for reconstitution of their activity.A large reduction in bioluminescence was observed due to the DF process;0.07-0.58 times that of the non deep-frozen(NDF) immobilized strain.The decreased bioluminescence activity induced by the DF process was enhanced by the stimulants,sodium lactate(SL) and KNO 3.However,regardless of the inducer chemical tested,the immobilized strain modified with KNO 3 consistently produced greater bioluminescence than that treated with SL,in the range of 3.0-10.7(avg.6.7 ± 3.69) and 1.2-4.2(avg.2.4 ± 1.47) times that of control,respectively.All KNO 3 treatments of contaminated groundwater samples also resulted in an increase in bioluminescence activity,but the rate of stimulation varied for each sample.Also,no strong linear correlation was observed between the bioluminescence and the total concentration of an inducer,which may related to the complex characteristics of the environmental samples.Overall,the results demonstrated the ability of immobilized genetically engineered bacteria,preserved by DF,to measure a specific group of environmental contaminants using a stimulating agent(KNO 3),suggesting the potential for its preliminary application in a field-ready bioassay.     

国家环境信托基金

国家环境信托基金（NETFUND）是“环境管理协调法案”简化了77个零散环境立法机构,为了环境管理、能力建设、环境奖励、环保刊物和学者筹集基金而建立起来的。“环境管理协调法案”旨在使国家环境管理战略与国际环境治理行动和协议相一致。国家环境信托基金仅是环境管理协调法案机构之一。     

金属离子鱼类急性毒性研究及对环境标准修订的启示意义

以斑马鱼和孔雀鱼为实验动物,进行了Cu^2＋、Cd^2＋、Zn^2＋和Cr^6＋的鱼类急性毒性试验。结果表明,这四种金属离子对受试鱼的毒性影响比较明显,对斑马鱼、孔雀鱼96 h半致死浓度分别为0.57 mg/L,12.59 mg/L,32.24 mg/L,62.27 mg/L和2.36 mg/L,17.71 mg/L,39.71 mg/L,43.40 mg/L。四种金属离子的毒性大小依次为：Cu^2＋〉Cd^2＋〉Zn^2＋〉Cr^6＋;Cu^2＋、Cd^2＋、Zn^2＋对斑马鱼的影响较大,Cr^6＋则对孔雀鱼的影响较大。结果同时对环境标准的修订具有启示意义,现行的国家《污水综合排放标准》（GB8978-1996）和国家《地表水环境质量标准》（GB3838-2002）对废水和水环境中Cu浓度的要求偏低,在符合国家标准的情况下Cu^2＋在低浓度水平就具有较大的毒性,未来污水排放标准和水环境质量标准在修订中应重视这个问题。     

高浓度豆制品废水预处理实验研究

豆制品是中国的传统食品,在生产过程中产生高浓度废水,如果对高浓度有机废水进行预处理,采用回收蛋白质以及化学混凝处理方法可以大大降低废水浓度,一定程度上可以减轻后续处理的难度、降低处理成本。针对豆制品生产废水问题,对高浓度豆制品废水的预处理方法作了实验研究。采用调节等电点酸沉降的方法回收蛋白质,然后用聚合硫酸铁化学混凝处理上清液以降低COD的含量。实验证明了方法的可行性并得出了最佳实验条件。     

我国森林环境修复的探讨

通过对我国森林环境现状的分析,提出了森林业当前存在的主要问题,并结合我国的国情与林情,对适合我国森林环境修复的对策与途径进行了深入的探讨.