外源基因在乳酸菌中的表达

乳酸菌表达系统是近几年发展起来的一种高效表达系统．由于许多乳酸菌具有益生菌的特点，该系统已被广泛用于外源基因的表达．相对于其他细菌表达系统而言，乳酸菌表达系统具有多种优势．本文就该系统的优势及其发展前景进行了阐述．参20     

应用发光菌测定有机化合物的毒性

本文介绍了化合物对发光菌半数抑制发光强度的毒性测定方法，测定了几十种芳烃类化合物的毒性，发现不同取代基或取代位置的芳烃毒性不同，并且对发光菌的毒性与对黑呆头鱼的毒性有相关性。     

生物除铁除锰滤层营养条件的研究

采用模拟生物除铁除锰滤柱,通过测定整个生物滤层对铁、锰的去除效果考察了营养物质对生物滤层综合生化能力的影响,从而探求了生物滤层对铁、碳、氮等营养元素的需求.结果表明,成熟滤层内的铁、锰氧化细菌对进水铁的营养需求极低(0.04 mg/L).成熟滤层对有机物具有一定的去除能力,而无机碳减少量相对较大,大约有3～4 mg/L,溶解在水中的二氧化碳即可保证滤层对碳的需求.成熟滤层将氨氮转化为硝酸盐和亚硝酸盐,但这种转化实际上并没有使水中氮的总量减少,只是氮的形态发生了转化;而滤柱内氮的减少是被生物体利用的结果.极低的氮素含量即可保证成熟生物滤层对氮素的需求.这表明极低的营养条件即可满足铁、锰氧化细菌的正常生理代谢,铁、锰氧化细菌可以在贫营养环境下生存.结合全国大部分地区的地下水水质状况,进而得出地下水生物除铁除锰技术在全国大部分地区可以推广使用.     

驯化矿化垃圾CH4氧化速率和N2O释放研究

利用畜禽废水驯化矿化垃圾,并将其与原生矿化垃圾和粘土对比,分析了土壤理化性质、含水率、温度等对CH4氧化能力和N2O释放的影响.研究表明:驯化矿化垃圾对CH4的氧化能力(15.48 μmol·g-·h-1)明显高于原生矿化垃圾和所选粘土土样;材料的粒径尺寸、有机质、氨氮硝化率及硝态氮生成率均与CH4氧化能力有着显著的正相关性;驯化矿化垃圾在加入蒸馏水后释放大量的N2O,产生N2O的量是原生矿化垃圾的2倍,并且比粘土高一个数量级.由于驯化矿化垃圾对环境的适应能力强,CH4氧化能力高,进而能够减少温室气体排放,可作为一种较为理想的填埋场覆土材料.     

Landbased Pollution Sources and Marine Environmental Quality in the Caribbean

Abstract

The near shore coastal and marine environment of several Caribbean islands is their most biologically productive and economically important zone. However, almost all landbased activities possess the real potential of degrading the quality of near shore waters and ultimately diminishing the utility of the marine resource. This condition is largely attributed to the individual smallness of the islands and their geographic proximity to each other.

Available sanitary water quality data from across the region indicated that while recreational areas are in general safe for water contact activities, bacterial densities in excess of several international criteria are consistently recorded in harbours. Organochlorine pesticide residues were generally in the 5 ng l^?1 range in unfiltered sea water but were significantly higher (1–100) ng g^?1 in limited samples of sediment and biota. Additional data requirements to gain further insight into the current state of the Caribbean environment are also identified.

A summary of the major land based sources of marine pollution (including sewage, industrial effluents and agricultural run-off) in the insular Caribbean is presented.     

Acid mine drainage attenuation by inhibition of pyrite bioleaching using limestone and olive pomace

The control and inhibition of pyrite bioleaching involved in the generation of acid mine drainage was studied. Inhibition of pyrite bioleaching was performed by varying the pyrite concentration in the medium (substrate inhibition) and/or by addition of limestone (inhibition by pH increase) and olive pomace (inhibition by organic compounds). Inhibition tests of pyrite bioleaching were performed according to a full factorial design with three factors (pyrite, limestone and olive pomace) taken at two levels. Preliminary pyrite bioleaching tests showed the ability of the available inoculum to oxidise the mineral. Subsequently, experimental data for total soluble iron denoted strong inhibition under all the different operating conditions of the factorial design, except when larger pyrite concentrations were used. In particular, inhibition by limestone was due to the increase in pH which negatively affects microorganisms, while inhibition by olive pomace may be related to the antioxidant properties of polyphenols. Interactions among operating conditions were specifically assessed by analysis of variance. Only limestone and/or pomace addition resulted in a significant (95%) diminution of iron extraction.     

Photobiological production of hydrogen by the waste water treatment with anaerobic photosynthetic Purple bacteria

In this paper selected references about experience gained with photosynthetic bacteria in anaerobic process for either water treatment or hydrogen production are given. In particular experimental data about the hydrogen evolution rate, hydrogen yield and substrate efficiency in relationship to the nutrient conditions as well as about the behavior of some different species are presented. The limiting role of the nitrogen source is being discussed.     

Inactivation of bacteria by sun light in a solar reactor with Immobilised TiO2

The photocatalytical inactivation of bacteria (Escherichia coli, Staphylococcus epidermidis,...) in the flow‐through plate solar reactor by sunlight was investigated. The low stability of bacteria in the reactor was attributed to bacteria sensitivity to mixing and/or gas bubbling. Sunlight inactivation proceeds with sufficient rate even under cloudy conditions.     

苯并噻唑类污染物对青海弧菌Q67毒性效应

以青海弧菌Q67为指示生物,结合96微孔板高通量检测技术,测定了10种环境中常见苯并噻唑类污染物对发光菌的毒性效应。结果表明,10种苯并噻唑化合物均对发光菌具有毒性效应,其EC50在1.17×10-6~5.43×10-3mol·L-1之间。对其进行毒性效应排序,发现巯基取代氨基2羟苯基羧酸乙酯溴氟甲基氯甲硫基苯并噻唑。利用结构化学描述符和偏最小二乘法,构建了苯并噻唑类化合物对Q67发光菌毒性的定量构效关系模型(QSAR),结果发现,氢键供体数量(ND)和极性溶剂可及分子表面积(PSASA)对其毒性具有重要意义。本研究为苯并噻唑类污染物毒性效应评价及其环境风险评价提供了参考。