海水中痕量金属元素对海洋生物作用研究的进展

海水中痕量金属元素对海洋生物作用研究的进展袁有宪，曲克明（中国水产科学研究院黄海水产研究所，青岛２６６０７１）ＡＤＶＡＮＣＥＳＯＦＩＮＶＥＳＴＩＧＡＴＩＯＮＯＮＴＨＥＡＣＴＩＯＮＯＦＴＲＡＣＥＭＥＴＡＬＩＮＳＥＡＷＡＴＥＲＴＯＭＡＲＩＮＥＯＲＧＡＮＩ...     

氨氧化菌及其在中国池塘养殖水质调控过程中的应用

氨氮是池塘养殖尾水治理过程中需着重考虑的一种污染物,池塘养殖环境氨氮氧化去除主要依赖氨氧化细菌、氨氧化古菌和厌氧氨氧化菌。本研究介绍了在自然界中已发现的几种氨氧化菌的氮素代谢机理,并结合池塘生态系统特征,着重从温度、pH、溶解氧、附着基质和光照角度,阐释氨氧化菌对池塘养殖水体的生态调控机制。基于氨氧化菌附着生活习性,现已研发出多种异位池塘养殖水质净化技术,在一定程度上,这些技术能发挥净水效果,但普遍存在占地面积大,造价高、效率低等问题。目前,中国池塘养殖水体处理领域,在氨氧化微生物菌剂和高效微生物反应器应用及研发方面比较薄弱。建议未来强化池塘低温高效氨氧化菌株筛选和富集培养研究,促进结构紧凑型水处理微生物反应器研发,丰富淡水池塘养殖尾水氨氮去除手段。     

High inoculum of Monilinia fructicola is a threat to peach production in the tropics due to fruit susceptibility at all development stages

Brown rot is the main disease of stone fruits in Brazil, but the susceptibility of peaches to brown rot at different stages of development in the field has not been studied under subtropical conditions. This information is relevant to guide the management of the disease. The objective of this research was to determine the influence of inoculating peaches with Monilinia fructicola at different stages of development on the infection and progress of brown rot at postharvest. Two experiments were carried out: one ex vivo with two cultivars and the other in the field for two seasons. Peaches were inoculated at different sizes for both experiments. In the field, peaches were bagged to avoid natural infection, and M. fructicola inoculum was monitored. The ex vivo incidence of the disease was lower at pit hardening than at other fruit stages for both cultivars. The incidence of brown rot for peaches attached to the trees increased with fruit ripening. Conversely, the time for symptom expression was reduced according to peach diameter. Peaches inoculated with a diameter smaller than 2 cm showed a lower incidence of brown rot and longer periods for disease expression than fruit inoculated near harvest. In conclusion, in areas with high inoculum in the orchard, a common condition in the subtropics, the grower must prevent infection at all stages of fruit development, thus avoiding losses during marketing.     

Gram-Negative Marine Bacteria: Structural Features of Lipopolysaccharides and Their Relevance for Economically Important Diseases

Gram-negative marine bacteria can thrive in harsh oceanic conditions, partly because of the structural diversity of the cell wall and its components, particularly lipopolysaccharide (LPS). LPS is composed of three main parts, an O-antigen, lipid A, and a core region, all of which display immense structural variations among different bacterial species. These components not only provide cell integrity but also elicit an immune response in the host, which ranges from other marine organisms to humans. Toll-like receptor 4 and its homologs are the dedicated receptors that detect LPS and trigger the immune system to respond, often causing a wide variety of inflammatory diseases and even death. This review describes the structural organization of selected LPSes and their association with economically important diseases in marine organisms. In addition, the potential therapeutic use of LPS as an immune adjuvant in different diseases is highlighted.     

污水处理反硝化除磷-诱导结晶磷回收工艺中除磷微生物特性

为探究反硝化除磷-诱导结晶磷回收工艺中缺氧池污泥释磷、吸磷以及微生物特征,利用荧光原位杂交(fluorescence in situ hybridization,FISH)技术、电子扫描显微镜(scanning electron microscope,SEM)观察了微生物的数量、分布和形态;通过批次试验考察了污泥在厌氧/好氧和厌氧/缺氧2种模式下的释磷和吸磷特征。结果表明:该双污泥系统缺氧池中聚磷菌占总细菌比例的69.7%,明显高于单污泥系统中富集的聚磷菌比例,污泥中的微生物多呈杆状;厌氧/好氧、厌氧/缺氧模式下单位污泥浓度(mixed liquor suspended solids,MLSS)总吸磷量(以PO43--P计)分别为22.84、18.60 mg/g,反硝化聚磷菌(denitrifying polyphosphate-accumulating organisms,DPAO)占聚磷菌(polyphosphate-accumulating organisms,PAO)的比例为81.44%,表明在长期的厌氧/缺氧运行条件下可以富集到以硝酸盐为电子受体的反硝化聚磷菌,同时还存在着仅以氧气为电子受体的聚磷菌;通过pH值和氧化还原电位(oxidation reduction potential,ORP)的实时监测可以快速地了解污水生物处理系统中各类反应的进程,对调控工艺参数有着重要的意义。综上所述,为保证污水生物处理工艺的正常稳定运行,将微生物分析与常规的化学参数分析结合起来考察将是未来发展的必然趋势。     

Biocontrol strain Pseudomonas fluorescens CHA0 and its genetically modified derivative with enhanced biocontrol capability exert comparable effects on the structure of a Sinorhizobium meliloti population in gnotobiotic systems

The impact of biocontrol strain Pseudomonas fluorescens CHA0 and of its genetically modified, antibiotic-overproducing derivative CHA0/pME3424 on a reconstructed population of the plant-beneficial Sinorhizobium meliloti bacteria was assessed in gnotobiotic systems. In sterile soil, the final density of the reconstructed S. meliloti population decreased by more than one order of magnitude in the presence of either of the Pseudomonas strains when compared to a control without addition of P. fluorescens. Moreover, there was a change in the proportion of each individual S. meliloti strain within the population. Plant tests also revealed changes in the nodulating S. meliloti population in the presence of strains CHA0 or CHA0/pME3424. In both treatments one S. meliloti strain, f43, was significantly reduced in its root nodule occupancy. Analysis of alfalfa yields showed a slight but statistically significant increase in shoot dry weight when strain CHA0 was added to the reconstructed S. meliloti population whereas no such effect was observed with CHA0/pME3424.     

宜丰县林业有害生物发生状况及治理对策

宜丰县林业有害生物的发生防控形势日趋严峻,主要发生危害种类20余种,对全县的生态环境构成严重的威胁。要加强监控,做好综防工作。     

转基因生物体对生态环境的影响及其发展趋向

转基因生物体包括转基因植物、动物和微生物。目前转基因生物体的研究主要集中于转基因植物与动物的研究。文中主要论述转基因植物对生态环境的影响及其发展趋势。对转基因植物对生态环境产生的影响和可能产生的后果进行了系统的分析，并且重点评述转基因植物对土壤生态系统及土壤微生态系统的影响及进展；对其影响的评价体系和今后的发展方向等有争议的问题进行了阐述并提出了新的思路。     

Effects of liming,fertilization and acidification on pH,soil moisture,and ATP content of soil from a spruce forest in Southern Germany

Short-term and medíum-term effects of liming (CaCO₃), fertilization [5Ca(NO)₃)₂·NH₄NO₃], and acidification on soil bioactivity were measured in a spruce stand in Southern Germany. The experiment was set up in a randomized block design. Acid precipitation lowered the pH, liming increased the pH, while fertilization caused only small alterations in pH values. Significant differences in soil moisture occurred only in the mineral horizons. The soil ATP content of the humus layers decreased in all plots (control included) up to day 100. On all sampling dates, a pronounced decrease in ATP content followed the acidification. Minor decreases in ATP were observed after fertilization, while liming produced no defined effects. Similar trends, but less pronounced, were observed in the mineral horizons. Only a few significant correlations were found between pH values and ATP or between moisture and ATP within a treatment and sampling date. Present address: Institut für Biologie II (Zoologie), RWTH Aachen, Kopernikusstrasse 16, D-52056 Aachen, Germany