Midwater biomass profiles over the Madeira Abyssal Plain and the contribution of copepods

Biomass profiles for plankton and micronekton throughout the water column at a site on the Madeira Abyssal Plain, position 31° 17 N 25° 24 W, depth 5 440 m, are described. Biomass declined exponentially with depth, > 80% of the plankton and > 95% of micronekton occured between 0–1000 m. The total biomass was low, ca 2 g dry weight below each m² of sea surface but this situation is probably not abnormal and reflects the paucity of biota at abyssal depths. Plankton and micronekton profiles were strikingly similar at depths below 1700 m. In contrast to previous observations there was no dramatic increase in biomass just above the bottom. Comparisons with previous data suggest that the processes controlling the distribution of biomass in the deep oceans are similar despite differences in overlying surface production. The most numerous planktonic group were copepods and the plankton biomass profiles mirror their abundance profiles. The proportion of dead: living copepods has been estimated for depths > 1500 m: the relative constancy of the proportions in midwater may be attributable to detritivory. Immediately above the bottom the proportion of carcases increased and the proportion of non calanoid copepods also increased. Total numbers of copepods increased markedly in a haul which hit the bottom, this may be due to a specialised population living very close to the sea bed.     

Microbial Biomass, Activity, and Community Structure of Water and Particulates Retrieved by Backflow from a Waterflood Injection Well

Oil field injection water was allowed to back flow from two wells at the Packard drill site in Los Angeles, Calif., and was sampled at various times to obtain information about the biomass, potential activity, and community structure of the microbiota in the reservoir formation and in the injection water. Biomass was greatest in water samples that came from the zone near the injection site and dropped off sharply in subsequent samples, which were assumed to come from zones farther away from the well. Samples obtained from near the well also had visible exopolysaccharide blankets, as seen in scanning electron microscopic preparations. In one of the wells that was sampled, rates of glucose or acetate incorporation into microbial lipids correlated with biomass; but in the other well, activities correlated with the sampling time (volume of water that back flowed). Transmission electron micrographs showed a diverse, gram-negative bacterial population in a variety of physiological states. The analysis of the phospholipid ester-linked fatty acid profiles of the samples revealed consistently large proportions of 18:1ω7c fatty acids, indicating the presence of many anaerobes, facultative organisms, or both. Proportions of cyclopropyl fatty acids and ratios of trans/cis monoenoic compounds increased with the volume of water that back flowed (analogous with the distance into the formation), while the ratio of unsaturated/saturated compounds decreased, possibly indicating higher levels of stress or starvation in the microbial communities farthest from the injection well. Greater than 90% of the total biomass was trapped on glass fiber filters, indicating that the microbiota were largely attached to particles or were clumped. These sampling techniques and analytical methods may prove useful in monitoring for problems with microbes (e.g., plugging) in waterflood operations and in the preparation of water injection wells for enhanced oil recovery by the use of microbes.     

Influence of Deep Ocean Sewage Outfalls on the Microbial Activity of the Surrounding Sediment

The microbial activity near two deep ocean sewage outfalls off the coast of the island of Oahu, Hawaii, was characterized. Water samples and sediment samples to a depth of 4.5 cm were analyzed from an area of approximately 4.5 × 10⁴ m² surrounding the outfalls. Although the effluent water at both sites exhibited heterotrophic activity that was 2 orders of magnitude greater than water from a control site, ambient water samples taken within 1 m of the discharge ports exhibited activity only twice that of the control water. The heterotrophic activity of the outfall sediment was only elevated above that of the control site for surface samples collected within 10 m of the outfall. Likewise, the rates of microbial nucleic acid synthesis and carbon production in the sediment were only elevated immediately adjacent to the outfalls. Total microbial biomass, as determined by the ATP content of the sediment, varied spatially but was generally elevated at the outfall sites. The specific growth rates calculated for the sediment microbial populations, however, were not greater at the outfall sites. At one site the rocks surrounding the diffuser pipe were covered with copious amounts of slime that appeared to be composed entirely of microbial cells and filaments. This microbial mat was extremely active with respect to heterotrophic activity and biomass production. Overall, it appears that the impact of the sewage discharge on the ambient seawater microbiota is slight and that the effect on the sediment microbiota is confined to an area immediately adjacent to the diffuser ports. In the sand itself, the effect is limited to the upper 2 cm at most.     

Improved Recoverability of Microbial Colonies from Marine Sponge Samples

Abstract The growth of microorganisms from marine sponge samples was studied on various low to high nutrient solid media using media supplements. The supplements utilized were catalase, sodium pyruvate, and a combination of the two. Medium composition was found to influence the growth response on the supplemented media. Microorganisms on low nutrient media responded more favorably to the media additions than on high nutrient media. Thirty-five percent of the supplemented media demonstrated colony forming unit (CFU) recoveries that were 50% or greater than those of the unamended control plates. Twenty-one percent showed recoveries of more than 100% of the control values, with sodium pyruvate additions providing for the greatest overall increase in recovery, whether alone or in conjunction with catalase. These findings suggest that addition of catalase or sodium pyruvate to solid growth and isolation media may improve recoverability of microorganisms from natural samples. Received: 24 January 2000; Accepted: 9 June 2000; Online Publication: 28 August 2000     

The Speciation of Organotin Compounds in Sediment and Water Samples from the Port of Gdynia

Organotin compounds (OTC) are toxic towards all living organisms. The application of organitin-based antifouling systems is becoming the main source of OTC in the ocean. Harbor sediments and water contain large deposits of organotin compounds due to application of antifouling systems in the shipping industry. OTC contamination presents a potential risk to the marine environment.

Sediment and water samples were collected in 2009 from Gdynia Harbor. For all the analyzed organotin compounds, the mean concentration values were determined: water samples monobutyltin (MBT): 13.2, dibutyltin (DBT): 16.7, tributyltin (TBT): 60.7 (ng cation dm^?3), and sediment samples MBT: 261.4, DBT: 751.9, TBT: 2148.2 (ng cation g^?1 d.w.). The estimated content of monophenyltin (MPhT), diphenyltin (DPhT), triphenyltin (TPhT), monooctyltin (MOT), dioctyltin (DOT), and tricyclohexyltin (TCHT) were below the detection limit of the applied method. It was found that the content of organic matter, the amount of fine fraction, and the pH all play a significant role in the distribution and sorption process of OTC between the water and the sediment on the bottom. Compared to an earlier study, the concentrations of all OTC are much lower, confirming that the applied legislation has had a positive impact.     

Formation of Siderite in Microbial Microcosms Derived from a Marine Sediment

Abstract

Exceptionally well-preserved fossils are frequently encased by carbonate concretions. The initial steps of their formation in marine and freshwater sediments are induced by microbial activity. The role of the involved microbial communities, however, is not well understood. In this study, siderite (FeCO₃) formation in microbial microcosms is observed, with various fatty acyl compounds (lipids, surfactants) as substrates and Wadden Sea sediment samples as inocula. In actively growing microcosms, sulfate-reducing bacteria (the genus Desulfofrigus in particular) dominate the microbial community and submicroscopic siderite precipitates on bacterial cell surfaces were identified. We suggest that these biologically induced mineralization processes may, in the natural environment, initiate the formation of large concretions under suboxic conditions in coastal sediments.     

A Study of Deep-Sea Natural Microbial Populations and Barophilic Pure Cultures Using a High-Pressure Chemostat

Continuous cultures in which a high-pressure chemostat was used were employed to study the growth responses of (i) deep-sea microbial populations with the naturally occurring carbon available in seawater and with limiting concentrations of supplemental organic substrates and (ii) pure cultures of copiotrophic barophilic and barotolerant deep-sea isolates in the presence of limiting carbon concentrations at various pressures, dilution rates, and temperatures. We found that the growth rates of natural populations could not be measured or were extremely low (e.g., a doubling time of 629 h), as determined from the difference between the dilution rate and the washout rate. A low concentration of supplemental carbon (0.33 mg/liter) resulted in positive growth responses in the natural population, which resulted in an increase in the number of cells and eventually a steady population of cells. We found that the growth responses to imposed growth pressure by barophilic and barotolerant pure-culture isolates that were previously isolated and characterized under high-nutrient-concentration conditions were maintained under the low-nutrient-concentration limiting conditions (0.33 to 3.33 mg of C per liter) characteristic of the deep-sea environment. Our results indicate that deep-sea microbes can respond to small changes in substrate availability. Also, barophilic microbes that are copiotrophic as determined by their isolation in the presence of high carbon concentrations and their preference for high carbon concentrations are versatile and are able to compete and grow as barophiles in the low-carbon-concentration oligotrophic deep-sea environment in which they normally exist.     

Microbial Activities in Undecompressed and Decompressed Deep-Seawater Samples

Microbial transformations of ¹⁴C-labeled substrates (sodium glutamate, Casamino Acids, glucose, and sodium acetate) were measured in undecompressed seawater samples collected from depths of 1,800 to 6,000 m, during 14- to 21-day incubation periods at in situ temperature (3°C). Each substrate was tested at two concentrations (ca. 0.5 and 5.0 μg/ml) and two in situ pressures. The data were compared to 1-atmosphere (ca. 1.013 × 10² kPa) controls. The rates of ¹⁴C incorporation and ¹⁴CO₂ production as well as the amounts of total substrate utilization were generally lower at pressure than in the decompressed controls but were significantly different for each of the four substrates used. The utilization of acetate was the least affected by pressure; rates were similar to those measured at 1 atmosphere in two out of four experiments. In contrast, transformation rates of the amino acids at pressure averaged to only 38% of those in the controls. A single but reproducible “barophilic” response was observed with glucose as a substrate in samples collected from a depth of 4,500 m at a specific area in the northwestern Atlantic Ocean. Except for this latter set of experiments, the transformation of all substrates showed an increased lag period at pressure as compared to the 1-atmosphere controls.     

A new deep-sea pennatulacean (Anthozoa: Octocorallia: Chunellidae) from the Porcupine Abyssal Plain (NE Atlantic)

During the BENGAL cruises, an important collection of deep-sea benthic organisms was sampled. Among the pennatulacean colonies, a previously undescribed species of chunellid was collected. That material is here described as the type species of a new genus, Porcupinella gen. nov. The new genus and species are described based on material collected in the Porcupine Abyssal Plain (NE Atlantic), 4,839–4,847 m in depth. This is the first time that a chunellid is reported from the Atlantic Ocean. The new genus is compared with the other genera in the family, and some phylogenetic remarks about the families Chunellidae and Umbellulidae are also provided.     

大连地区海泥样品中分离的五株海洋放线菌的研究

对从大连小平岛地区海面下10~20 m处的海泥样品中分离的5株海洋放线菌进行了生理特征和抗菌活性的研究。抗菌活性实验初步表明,菌株S097,S187和S233具有较好的拮抗革兰氏阳性菌、革兰氏阴性菌和真菌测试菌株的活性,尤其是菌株S233对绿脓杆菌和白色假丝酵母的抑制活性很强。16 s rDNA序列分析结果表明,5株放线菌(S097,S187,S233,S239,L180)分别与Streptomyces argenteolusCGMCC 4.1693、S.flavofuscusNRRL B-8036、S.variabilisNRRL B-3984T、S.lit-m ocidiniNRRL B-3635和S.sulphureusNRRL B-1627T显示出最高的序列同源性(99%),这是这些菌种首次报道在大连地区的海泥样品中得到分离。利用I型聚酮合成酶(PKSI)兼并引物从菌株S187中扩增出了PKSI片段,揭示了该菌株生产I型聚酮类化合物的潜在能力。本文的研究结果为进一步开发利用大连地区海泥中的海洋放线菌资源奠定了基础。     

Microbial Community Analysis of Anodes from Sediment Microbial Fuel Cells Powered by Rhizodeposits of Living Rice Plants

By placing the anode of a sediment microbial fuel cell (SMFC) in the rhizosphere of a rice plant, root-excreted rhizodeposits can be microbially oxidized with concomitant current generation. Here, various molecular techniques were used to characterize the composition of bacterial and archaeal communities on such anodes, as influenced by electrical circuitry, sediment matrix, and the presence of plants. Closed-circuit anodes in potting soil were enriched with Desulfobulbus-like species, members of the family Geobacteraceae, and as yet uncultured representatives of the domain Archaea.Living plants release substantial amounts of carbon in the soil as rhizodeposits, which are to a large extent transformed into the greenhouse gas methane in wetlands (21). It was recently demonstrated (8, 33) that the rhizodeposits can be harvested by plant microbial fuel cells (plant MFCs) and transformed into electricity. In its most straightforward form, a plant MFC is an adaptation of a sediment MFC (SMFC), which has an anode buried in (planted) sediment, allowing (microbial) oxidation of reduced compounds, and a cathode in the overlying water.The roots and surrounding rhizosphere in a plant SMFC add an extra parameter to the as yet multifaceted SMFC system. In the present study, two molecular profiling techniques (denaturing gradient gel electrophoresis [DGGE] and terminal restriction fragment length polymorphism [T-RFLP]) will be applied to evaluate the effect of plant presence, support material, operation of the electrical circuit, and anode depth on the bacterial and archaeal communities associated with rice SMFC anodes. Phylogenetic analysis will give further insight in their composition.     

表土孢粉模拟的中国生物群区

根据中国第四纪孢粉数据库提供的 6 41个表土孢粉资料 ,利用孢粉生物群区化方法 ,建立了具有 6 86个孢粉类群、31类植物功能型和 14种生物群区的孢粉生物群区化模型。经过检验 ,该模型在模拟中国生物群区、生物群区垂直分异和水平梯度分析方面均取得理想结果。模型已实现了计算机程序化 ,为重建过去地质历史时期的古生物群区和古气候分析 ,提供客观、准确的模型工具。     

Rates of Microbial Metabolism in Deep Coastal Plain Aquifers

Rates of microbial metabolism in deep anaerobic aquifers of the Atlantic coastal plain of South Carolina were investigated by both microbiological and geochemical techniques. Rates of [2-¹⁴C]acetate and [U-¹⁴C]glucose oxidation as well as geochemical evidence indicated that metabolic rates were faster in the sandy sediments composing the aquifers than in the clayey sediments of the confining layers. In the sandy aquifer sediments, estimates of the rates of CO₂ production (millimoles of CO₂ per liter per year) based on the oxidation of [2-¹⁴C] acetate were 9.4 × 10⁻³ to 2.4 × 10⁻¹ for the Black Creek aquifer, 1.1 × 10⁻² for the Middendorf aquifer, and <7 × 10⁻⁵ for the Cape Fear aquifer. These estimates were at least 2 orders of magnitude lower than previously published estimates that were based on the accumulation of CO₂ in laboratory incubations of similar deep subsurface sediments. In contrast, geochemical modeling of groundwater chemistry changes along aquifer flowpaths gave rate estimates that ranged from 10⁻⁴ to 10⁻⁶ mmol of CO₂ per liter per year. The age of these sediments (ca. 80 million years) and their organic carbon content suggest that average rates of CO₂ production could have been no more than 10⁻⁴ mmol per liter per year. Thus, laboratory incubations may greatly overestimate the in situ rates of microbial metabolism in deep subsurface environments. This has important implications for the use of laboratory incubations in attempts to estimate biorestoration capacities of deep aquifers. The rate estimates from geochemical modeling indicate that deep aquifers are among the most oligotrophic aquatic environments in which there is ongoing microbial metabolism.     

Anaerobic Microbial Degradation of Polypropylene and Polyvinyl Chloride Samples

Microbiology - Resistance to biodegradation, which is among the most advantageous features of synthetic polymers, is also the reason for their accumulation in the environment and therefore...     

Microbial Diversity and Resistance to Copper in Metal-Contaminated Lake Sediment

Contamination of habitats with heavy metals has become a worldwide problem. We describe herein the analysis of lake sediment contaminated with high concentrations of copper as a consequence of mine milling disposal over a 100-year period. Copper concentrations in the sediment were found to vary with depth and ranged from 200 to 5500 ppm. Analysis of the microbial community with T-RFLP identified a minimum of 20 operational taxonomic units (OTU). T-RFLP analysis along a depth profile detected as many as nine shared OTUs across 15 centimeters, suggesting a conservation of community structure over this range. Only two genera, Arthrobacter and Ralstonia, were detected among 50 aerobic copper-resistant isolates cultivated on R2A, one of which (Ralstonia sp.) was characterized by the sequestration of copper, identified by electron diffraction scanning, in growing colonies. Scanning electron microscopy showed changes to the outer envelope of the cells when grown in the presence of copper. The copper-resistant Ralstonia isolates were also resistant to Ni, Cd, and Zn, showing two patterns of phenotypic resistant to these three metals in which either resistance to Zn or Ni was expressed in an isolate but never both.     

Epigenetic Segregation of Microbial Genomes from Complex Samples Using Restriction Endonucleases HpaII and McrB

We describe continuing work to develop restriction endonucleases as tools to enrich targeted genomes of interest from diverse populations. Two approaches were developed in parallel to segregate genomic DNA based on cytosine methylation. First, the methyl-sensitive endonuclease HpaII was used to bind non-CG methylated DNA. Second, a truncated fragment of McrB was used to bind CpG methylated DNA. Enrichment levels of microbial genomes can exceed 100-fold with HpaII allowing improved genomic detection and coverage of otherwise trace microbial genomes from sputum. Additionally, we observe interesting enrichment results that correlate with the methylation states not only of bacteria, but of fungi, viruses, a protist and plants. The methods presented here offer promise for testing biological samples for pathogens and global analysis of population methylomes.     

Extractable Microbial DNA Pool and Microbial Activity in Paleosols of Southern Urals

An evaluation of microbial DNA pools was performed using direct quantitative isolation of DNA from contemporary soils of Southern Urals and paleosols sealed under burial mounds early in the Bronze Age more than 5000 years B.P. Significant regression dependence was found between the biomass and DNA contents in these soils (R ²= 0.97). Activity and dominant ecological strategies of microbial communities of paleosols and contemporary southern black soil were compared from growth parameters obtained by analysis of respiratory curves. The ratio of maximum specific growth rates of soil microorganisms on glucose and on yeast extract was shown to provide an auxotrophy index for soil microbial communities.     

Microbial Biomass and Activity in Lead-Contaminated Soil

Microbial community diversity, potential microbial activity, and metal resistance were determined in three soils whose lead contents ranged from 0.00039 to 48 mmol of Pb kg of soil⁻¹. Biomass levels were directly related to lead content. A molecular analysis of 16S rRNAs suggested that each soil contained a complex, diverse microbial community. A statistical analysis of the phospholipid fatty acids indicated that the community in the soil having the highest lead content was not related to the communities in the other soils. All of the soils contained active microbial populations that mineralized [¹⁴C]glucose. In all samples, 10 to 15% of the total culturable bacteria were Pb resistant and had MIC of Pb for growth of 100 to 150 μM.