排序方式: 共有4条查询结果,搜索用时 15 毫秒
1
1.
Kaplan Hülya Ratering Stefan Hanauer Thomas Felix-Henningsen Peter Schnell Sylvia 《Biology and Fertility of Soils》2014,50(5):735-744
Biology and Fertility of Soils - Agriculturally used soils (Kastanozems) of experimental fields in the Mashavera Valley in southeast Georgia show various degrees of trace metal contamination (Cd,... 相似文献
2.
Mohamed Hemida Abd-Alla Shymaa R. Bashandy Sylvia Schnell Stefan Ratering 《Phytoparasitica》2011,39(2):175-183
Bacterial contamination of fresh tomato fruits is of great concern. From naturally infected tomato fruits showing dark brown
irregularly shaped spots, 36 bacterial isolates were recovered and identified on phenotypic characteristics and sequences
of the gene encoding the 16S rRNA. Five isolates showing spots on tomato fruits in the pathogenicity test with healthy tomato
fruits belong to the genus Serratia on the basis of phenotypic characteristics. One representative isolate of these has been further identified as a Serratia rubidaea by sequencing of the 16S rRNA gene. This is the first evidence showing that a S. rubidaea strain can cause spots on tomato fruits. Virulence of the S. rubidaea was also confirmed by the production and secretion of a large variety of enzymes capable of degrading the complex polysaccharides
of the plant cell wall and membrane constituents. Nineteen bacterial isolates of the 36 did not induce any spot symptoms in
a pathogenicity test on artificially infected tomato fruits although these are known as phytopathogenic bacteria. Five of
these 19 bacterial isolates were identified as Ralstonia species on the basis of biochemical tests. Sequencing of the 16S ribosomal gene of one representative isolate revealed that
the isolate is closely related to Ralstonia solanacearum. Six isolates of the 19 were related to Xanthomonas vesicatoria on the basis of biochemical tests and eight were related to the Enterobacteriaceae. One representative isolate of the Enterobacteriaceae could be identified by the 16S rRNA gene as Enterobacter cloacae subsp. dissolvens. The 12 other strains were related to Proteus mirabilis based on the 16S RNA gene sequence of one representative isolate. The isolates related to P. mirabilis did not produce any symptoms on artificially infected tomato fruits. The nucleotide sequences of S. rubidaea strain E9, E. cloacae strain E23, P. mirabilis strain E11, and R. solanacearum strain E15 have been deposited in the GenBank nucleotide sequence database under accession numbers HM585373 to HM585376. 相似文献
3.
Oily waste containing natural radionuclides: does it cause stimulation or inhibition of soil bacterial community?
下载免费PDF全文
![点击此处可从《植物养料与土壤学杂志》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Polina Galitskaya Raushaniya Gumerova Stefan Ratering Sylvia Schnell Evgenia Blagodatskaya Svetlana Selivanovskaya 《植物养料与土壤学杂志》2015,178(6):825-833
Contamination with oily wastes containing natural radionuclides is a potential hazard for soil health and function. Our study aimed to reveal both structural and functional changes of the microbial community resistant to and able to decompose oily wastes in soil. To do this, we determined CO2 efflux, microbial biomass (by the extraction‐fumigation method), and community structure (by PCR‐SSCP) for 120 d after application of radioactive oily wastes to the soil at the ratio 1:4. The addition of the waste resulted in an increase of the activity concentration of 226Ra by 130 times (up to 643 Bq kg?1) and of 232Th by 29 times (up to 254 Bq kg?1). The calculated weighted dose for the radionuclide 226Ra was found to be below the values that are known to affect microorganisms. However, the cumulative effect of a repeated deposition of radioactive oily waste may result in an increase of the weighted dose up to an effective level. During the incubation, the hydrocarbon (HC) content of the waste‐treated soil decreased from 156 to 54 g kg?1 of soil indicating intensive decomposition of added organics by soil microorganisms. The waste application, however, led to an inhibition of soil microbial biomass compared with the control (by 26–47%). Microbial respiration was stimulated in the first month of incubation and then decreased until the end of the incubation period (by up to 74% compared to the control). The qCO2 was estimated to be 3‐fold higher than the control on day 1 of incubation and equal to the control on day 120 of incubation. The bacterial diversity decreased in the contaminated soil compared with the control soil. The bacterial community structure was altered by domination of new oil degrader species belonging to the genera Dyella, Pseudoxanthomonas, Sinobacter, and Parvibaculum. Thus, disposal of radioactive petroleum waste strongly altered the structure of the microbial community resulting in the selection of resistant species able to decompose pollutants and also affected the community function (inhibition of microbial biomass and stimulation of respiration) which tended to stabilize after long‐term incubation. 相似文献
4.
Claudia?KammannEmail authorView authors OrcID profile Stefan?Ratering Carolyn-Monika?G?rres Cécile?Guillet Christoph?Müller 《Biology and Fertility of Soils》2017,53(5):491-499
In this study, the impact of rose chafer (Cetonia aurata L.) larvae on net and gross methane (CH4) fluxes in soil from an old permanent grassland site (Giessen, Germany) was investigated. Previous studies at this site suggested the existence of Scarabaeidae larvae-induced “CH4-emitting hot spots” within the soil profile which may subsequently lead to increased CH4 oxidation. The net (soil + larvae) and gross (soil and larvae separated) CH4 fluxes were studied in a 3-month laboratory incubation. Addition of larvae changed the soil from a net sink (?330 ± 11 ng CH4 kg?1 h?1) to a net source (637 ± 205 ng CH4 kg?1 h?1). Supply of plant litter to the soil + larvae incubation jars tended to increase CH4 emissions which was not significant due to large variability. After 11–13 weeks of incubation, the net soil CH4 oxidation was significantly stimulated by 13–21% in the treatments containing larvae when these were taken out. Analysis of archaeal 16S rRNA genes revealed that the majority of the obtained clones were closely related to uncultured methanogens from guts of insects and other animals. Other sequences were relative to cultivated species of Methanobrevibacter, Methanoculleus, and Methanosarcina. Hence, Scarabaeidae larvae in soils (i) may represent an underestimated source of CH4 emissions in aerobic upland soils, (ii) may stimulate gross CH4 consumption in their direct soil environment, and, thus, (iii) contribute to the spatial heterogeneity often observed in the field with closed-chamber measurements. Long-term CH4-flux balances may be wrongly assessed when “exceptional” net CH4 flux rates (due to larvae hot spots) are excluded from data sets. 相似文献
1