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51.
Community structure in a methanotroph biofilter as revealed by phospholipid fatty acid analysis 总被引:1,自引:0,他引:1
The microbial community structure of two biofilters used for the oxidation of methane and organic trace gases generated in landfills was analysed by phospholipid fatty acid composition. Community structure varied with biofilter depth, reflecting varying conditions of substrate supply as well as of organic carbon content, nutrient status and osmotic stress determined by the different materials used for the individual biofilter layers. Both biofilters were dominated by type II methanotrophs. In the biofilter charged with landfill gas containing significant amounts of trace organics, fatty acid 18:1omega7c constituted 87% of the methanotrophic PLFA, while the recognised signature fatty acids 16:1omega8 and 18:1omega8, which were well represented in the other biofilter, were entirely absent. This indicates the development of a highly specific methanotrophic population, presumably as a result of the adaption to continuous organic trace gas exposure. 相似文献
52.
Pourcher A Sutra L Hébé I Moguedet G Bollet C Simoneau P Gardan L 《FEMS microbiology ecology》2001,34(3):229-241
Enumeration and phenotypic characterization of aerobic cellulolytic bacteria were performed on fresh, 1 year old and 5 years old refuse samples of a French landfill site. Numbers of cellulolytic bacteria ranged from 1.1x10(6) to 2.3x10(8) c.f.u. (g dry wt.)(-1) and were lower in 5 years old refuse samples. A numerical analysis of phenotypic data based on 80 biochemical tests and performed on 321 Gram-positive isolates from refuse, revealed a high phenotypic diversity of cellulolytic bacteria which were distributed into 21 clusters. Based on the phenotypic analysis and the sequencing of 16S rDNA of five representative strains of major clusters, the predominant cellulolytic groups could be assigned to the family of Bacillaceae and to the genera Cellulomonas, Microbacterium and Lactobacillus. Furthermore, chemical parameters such as pH, carbohydrates and volatile solid contents influenced the composition of the cellulolytic bacterial groups which were reduced essentially to the family of Bacillaceae in the oldest refuse samples. 相似文献
53.
Raül Ramos Francisco Ramírez Carolina Sanpera Lluís Jover Xavier Ruiz 《Journal of Ornithology》2009,150(1):265-272
In recent decades, the Yellow-legged Gull (Larus michahellis) has become a problematic species in many Mediterranean countries, mainly because it interferes with human interests. However,
this gull also has a negative impact on several other bird species, many of which are classified as endangered. Two different
European Union Action Plans are currently under development with the aim of decreasing the availability of food derived from
human activities, such as garbage and fishery discards, which are considered to be the main causes of the superpopulations
of this gull. Here, we describe the diet of Yellow-legged Gull chicks, with particular emphasis on establishing the dependence
of each population on refuse dumps, in order to forecast changes in gull population dynamics in response to the management
decisions being implemented. We sampled four colonies along the Western Mediterranean in Spain: the Medes Islands, the Ebro
Delta, the Columbretes Islands, and Mazarrón Island. To elucidate their feeding ecology and to avoid obtaining a discrete
estimation from a single sampling, we collected regurgitates from each colony three times throughout the chick-rearing period.
Slightly differential feeding habits were observed between chick age classes. Younger chicks in all four colonies tended to
be consistently provisioned with smaller prey such as invertebrates. Distinct uses of several foraging habitats among localities
were observed. In particular, the use of refuse dumps was common and abundant in two of the colonies: the Medes and Mazarrón
Islands. As a consequence of current management strategies, generalized reductions in Yellow-legged Gull populations and increases
in the consumption of alternative food resources to those of fishery discards and refuse scraps are expected. Finally, we
predict that decreased food availability will force some gulleries to increase predation on endangered species, thereby raising
a conservation concern.
X. Ruiz: deceased on 27 April 2008. 相似文献
54.
Debra R. Reinhart Frederick G. Pohland 《Journal of industrial microbiology & biotechnology》1991,8(3):193-199
Summary Co-disposal of 12 compounds representing major organic classes (aromatic hydrocarbons, halogenated hydrocarbons, pesticides, phenols, and phthalate esters) with shredded municipal solid waste was tested using a laboratory-scale column and pilot-scale lysimeter to characterize transport and transformation phenomena including sorption, volatilization and bioassimilation. Leachate and gases emitted from the lysimeters were examined for identifiable products of biotransformation. The results of this investigation provided a mechanistic evaluation of the attenuating and assimilative capacity of municipal solid waste landfills for specific organic compounds. Physical/chemical organic compound characteristics were related to refuse characteristics and composition to predict compound fate. Such knowledge is useful in developíng landfill management and operational strategies consistent with the need for control of pollutant releases. 相似文献
55.
56.
Total population of cellulose degrading bacteria was studied in a landfill ecosystem as a part of microbial diversity study.
Samples were obtained from 3 and 5 feet depth of a local landfill being operated for past 10 years. Among many isolates, 22
bacterial strains were selected based on their capability to decompose carboxymethyl cellulose (CMC). These isolates were
cultivated on agar medium with CMC as the carbon source. All isolates were Gram positive, endospore forming and alkalophilic
bacteria with optimum growth pH 9–10. They were grouped based on the phenotypic and chemotaxonomic characters and representative
strains of different groups along with high carboxymethyl cellulase (CMCase) producing strains were included for further characterization.
Analysis of 16S rRNA gene indicated that these strains belong to different species of the genus Bacillus. Maximum CMCase activity of 4.8 U/ml at 50°C was obtained by strain LFC15. Results in the present study indicated the potential
of waste land ecosystems such as landfill are potential source for isolation of industrially important microorganisms. 相似文献
57.
J. Nikiema R. Brzezinski M. Heitz 《Reviews in Environmental Science and Biotechnology》2007,6(4):261-284
The production of biogas in landfills, its composition and the problems resulting from its generation are all reviewed. Biofiltration
is a promising option for the control of emissions to atmosphere of the methane contained in biogas issued from the smaller
and/or older landfills. A detailed review of the methane biofiltration literature is presented. The microorganisms, mainly
the methanotrophs, involved in the methane biodegradation process, and their needs in terms of oxygen and carbon dioxide utilization,
are described. Moreover, the influence of nutrients such as copper, nitrogen and phosphorus, and the process operating conditions
such as temperature, pH and moisture content of the biofilter bed, are also presented. Finally, the performance of various
filter beds, in terms of their elimination capacities, is presented for laboratory scale biofilters and landfill covers. 相似文献