热带太平洋深海微生物的若干生理生态特征

从2001年春、秋季于热带太平洋区采集到的深海样品中共分离到110株微生物,从中挑取31株进行形态特征和对环境理化因子适应特征的研究,同时利用Biolog微生物自动鉴定系统进行菌种鉴定和碳源代谢分析.结果表明:31株微生物中2株为酵母,21株为革兰氏阳性细菌,8株为革兰氏阴性细菌,来自底质的细菌菌株阳性菌占优势,而海水、蓝藻中阴性菌居多;温度、盐度、pH适应性试验表明,严格意义上的狭适性微生物不到总数的1/3,而具有较宽生态幅的广适性微生物占有相当大的比例.另一方面,耐冷菌、中度嗜盐菌和抗碱菌在这些微生物中的比例很高,同时,来自蓝藻的菌株大多数在4℃下不生长,而来自上覆水和底质的菌株可在4℃生长,这些都体现了微生物对生存环境的响应.31株微生物经Biolog鉴定12株得出鉴定结果.15株革兰氏阳性细菌对95种碳源的利用能力分析表明,不同菌株可利用碳源的数目从3种到46种不等,差异很大,体现了深海微生物营养类型的极大多样性;同时,发现有8种碳源可被一半以上的受试菌株所利用,这些碳源均是微生物各类代谢途径中的重要中间代谢物.     

通用地震数据采集器EDAS-24GN中CPU数据收发方式

通用地震数据采集器EDAS-24GN引入一种新型的数据传输方式,通过AT91SAM9263CPU板带有的同步串行控制器进行数据传输,可以有效解决前一种方式存在的问题.经过实验验证,新型的数据传输方式在每秒传输50 kB数据时,引起的中断次数只有十几次,有效提高了CPU处理效率,且不存在数据丢失现象.     

Effects of contamination of single and combined cadmium and mercury on the soil microbial community structural diversity and functional diversity

To assess the effects of single and combined pollution of cadmium (Cd) and mercury (Hg) on soil micro-bial community structural and functional diversities, an incubation experiment was conducted, by employing two soils, namely, the marine sediment silty loam soil and the yellowish-red soil, in which five levels of Cd, Hg and Cd and Hg in combination were added. After being incubated for 56 days, the phospholipid fatty acids (PLFAs) profile and sole carbon source utilization pattern (BIOLOG) of the samples were tested. The results showed that the compo-sition of the microbial communities changed significantly at different levels of metals application. The principal component analyses (PCA) of PLFAs indicated that the structure of the microbial community was also significantly altered with increasing levels of metals, with increasing PLFAs biomarkers for fungi and actinomycetes, and in-creasing ratio of Gram-positive to Gram-negative bacteria. Sole carbon source utilization pattern analysis revealed that single and combined application of Cd and Hg inhibited significantly the functional activity of soil microorgan-isms, the functional diversity indices [Richness (S), Shannon-Wiener indices (H) and Evenness (EH)] were signifi-cantly lower in polluted soils than those in non-polluted soils, which also significantly altered with increasing levels of metals. PCA for the sole carbon source utilization pattern also indicated that the metal contamination could result in a variable soil microbial community. The results revealed that the combination of Cd and Hg had higher toxicity to soil microbial community structural and functional diversities than the individual application of Cd or Hg.     

用微生物对单一碳源利用方法探讨重金属在城市土壤中积累的环境效应

Biolog研究表明，英国阿伯丁市城市土壤的微生物群落结构显著有别于农村土壤，并使微生物对碳源的消耗量增加，消耗速度加快。城市土壤中不仅重金属Cu,Pb,Zn,Ni的含量明显高于农村土壤，而且其化学形态的主成分分析表明，有效态Pb,Zn,Cu及有机态Ni和Cu是导致城市土壤区分于农村土壤的主要因子。相关性分析表明，Biolog的这种变化规律与重金属的上述化学形态密切相关；典型变量分析表明，重金属对城市土壤微生物群落结果的这种损伤具有长期性效应及不可恢复性。     

柴油污染地下水修复生物反应墙中功能微生物数量及群落多样性

利用功能微生物、泥炭和含水层介质构建生物反应墙原位修复柴油污染地下水,系统经调试稳定后运行80 d,目标污染物去除率为83.60%~99.85%。运行期结束,采用荧光素-最大或然数和Biolog方法研究了生物墙内不同位置处功能微生物的数量及群落多样性。结果表明：墙体内各处均能保持较高的功能微生物数量,且微生物群落的物种数、丰富度、均一性、碳源利用性以及代谢特征均相似;但随着生物墙深度的增加,功能微生物比例有所下降,微生物群落略显丰富,但均一性略差,碳源利用倾向略微不同。生物反应墙原位修复地下水时,功能微生物能够长期保持较高的数量、较好的降解性能和稳定的群落多样性;但随着墙体深度的增加,营养结构发生了改变,导致微生物群落结构略显不同。     

Methods used to study bacterial diversity in the marine environment around Qingdao

Pollution has a considerable effect on biological communities, in terms of size and diversity of the populations. Yet, the precise consequences of human activity on microbial communities in the marine environment are poorly understood. Therefore, in an ongoing collaborative research programme between Heriot-Watt University and the Ocean University of Qingdao, bacteria were isolated in 1999 and 2000 from marine sediment, seawater, seaweed, fish and shellfish, taken from locations in Shandong Province adjacent to Qingdao. Sampling locations were comprised of industrial and aquacultural sites and a clean, control site. In order to analyse microbial diversity, a polyphasic approach was adopted for characterisation of these isolates, specifically through examination of key phenotypic traits, i.e. using Biolog GN MicroPlate^™ profiles, bacterial whole cell protein profiles and 16S and 23S rRNA gene sequences. These techniques yielded complex taxonomic data, which were subjected to statistical and cluster analyses. The application of these methods to studies of microbial communities is discussed.     

Effects of Nitrogen Fertilization on Soil Microbial Biomass and Community Functional Diversity in Temperate Grassland in Inner Mongolia,China

Nitrogen (N) fertilization may profoundly affect soil microbial communities. In this study, a field fertilization experiment was conducted in temperate grassland in Inner Mongolia, China to examine the effect of N fertilization on soil microbial properties and the main factors related to the characteristics of soil microbial community. Soil microbial biomass carbon (MBC) and microbial functional diversity along an N gradient were measured over three months (June to August). The result showed that N fertilization significantly decreased MBC under high N treatment (N200, 200 kg N ha^?1 y^?1) compared with the control (N0, 0 kg N ha^?1 y^?1) in the three months. Microbial functional diversity in July and August were significantly increased by low N treatment (N50, 50 kg N ha^?1 y^?1). Among the three fertilization treatments, microbial functional diversity under N200 in the three months was significantly lower than that of N50. The decrease of MBC and functional diversity under N200 were mainly due to the significant decline of plant belowground biomass under high N treatment. The increase of functional diversity under N50 treatment was due to the higher plant aboveground biomass as a result of the higher soil moisture availability. This finding highlighted that the higher N fertilization (N200) was not suitable for the growth and improvement of functional diversity of the soil microbial community, and that site and plant community play an important role in regulating the characteristics of soil microbial community.     

贵州赫章土法炼锌导致的土壤重金属污染特征及微生物生态效应

贵州省赫章县妈姑镇新关寨附近的土法炼锌不仅导致植被的破坏，而且使附近土壤中重金属有不同程度的积累，Zn达到162.23-877.88mg/kg,Pb为37.24-305.56mg/kg,Cd为0.50-16.43mg/kg，大大超过了当地的土壤背景值；而且重金属含量（特别是Pb和Zn含量）与土壤中的Fe2O3和Al2O3有极显著的正相关关系，显示土壤中铁氧化物和粘土矿物对重金属的固定作用。化学形态研究表明，Pb和Zn在土壤中主要表现为铁锰氧化物结合态与残渣态，而Cd的情况与Pb和Zn完全相反，其形态以可交换态为主。本区土壤微生物生物量（用含碳量表示）较低，仅为57.00-388.00μg/g，而且与土壤重金属间有显著的负相关关系，特别是与Zn的相关系数高达-0.7801，反映出重金属对微生物的毒害作用。Biolog测试结果表明，土壤微生物群落结构间没有明显的差别；土壤微生物DNA经PCR（聚合酶链式反应）和DGGE（变性梯度胶电泳）反应后的基因片段非常一致，反映出不同程度的重金属污染并没有导致土壤微生物群落结构的改变和基因损伤，另一方面也表明，土壤本身有强烈的固定重金属能力，抵御了重金属对土壤生物的进一步毒害。     

海藻叶面附着细菌群落生理特性与荧光原位杂交分析

实验对青岛沿海10月的石莼以及5月的石莼和裙带菜的叶面附着细菌群落进行了Biolog碳源利用实验,结果表明不同海藻表面的细菌群落碳源利用有较大的差异,且同一种海藻不同的采集时间其细菌群落也有较大的差异.荧光原位杂交方法表明采用EUB-fluo探针比SYBR-Green染色的效果要好; γ-Proteobacteria在不同海藻表面占据了较高的比例;裙带表面观察到了一些特异性链珠状细菌;石莼表面的细菌形态展示了较高的多样性.从海藻表面分离的优势菌落中分离到1株细菌,16SrDNA测序表明该序列与已知的Pseudoalteromonas16S rDNA序列的相似性为99.9%.本研究为海洋无环境公害防污材料的研究提供了一些新的思路.