scholarly journals Attached and Unattached Microbial Communities in a Simulated Basalt Aquifer under Fracture- and Porous-Flow Conditions

2001 ◽  
Vol 67 (6) ◽  
pp. 2799-2809 ◽  
Author(s):  
R. Michael Lehman ◽  
Frederick S. Colwell ◽  
Greg A. Bala
Keyword(s):  
Carbon Source ◽  
Acid Methyl Ester ◽  
Packed Columns ◽  
Most Probable Number ◽  
Total Biomass ◽  
Carbon Source Utilization ◽  
Probable Number ◽  
Geologic Medium ◽  
Utilization Patterns

ABSTRACT Bench scale column studies were used to examine the partitioning of microorganisms between groundwater and a geologic medium and to examine the effect of hydrogeology (i.e., porous- versus fracture-flow) on organism partitioning. Replicated columns were constructed with intact basalt core segments that contained natural fractures and with the same basalt crushed into particles. The columns were perfused with groundwater, and upon reaching a steady state, the columns were sacrificed and the attached and unattached communities were analyzed by multiple approaches. The analyses included the total number of cells, the phylogenetic affiliation of the cells (i.e., the α, β, and γ subclasses of the class Proteobacteria and gram positives with high G+C DNA content) by fluorescent in situ hybridization (FISH), number and taxonomic affiliation by fatty acid methyl ester profiles of culturable heterotrophs, most-probable-number estimates of methanotrophs and phenol oxidizers, and whole-community sole carbon source utilization patterns from Biolog GN microplates. In the packed columns, about 99% of the total biomass (per cubic centimeter of porous medium) was attached to the geologic medium. Lack of equitable units precluded a comparison of attached and unattached biomasses in the fractured columns where the attached biomass was expressed per unit of surface area. Compositional differences in the attached and unattached communities were evidenced by (i) the recovery ofPseudomonas stutzeri, an Enterococcus sp., andBacillus psychrophilus from the groundwater and not from the basalt, (ii) differences between community carbon source utilization patterns, and (iii) the relative abundances of different phylogenetic groups estimated by FISH in both column types. In the packed columns, attached communities were depleted of members of the α- and β-Proteobacteria subclasses in comparison to those in the corresponding groundwater. In the fractured columns, attached communities were enriched in gram-positive Bacteriaand γ-Proteobacteria and depleted of β-Proteobacteria, in comparison to those in the corresponding groundwater. Segregation of populations and their activities, possibly modified by attachment to geologic media, may influence contaminant fate and transport in the subsurface and impact other in situ applications.

General (Biolog GN) versus site-relevant (pollutant-dependent) sole-carbon-source utilization patterns as a means to approaching community functioning

1998 ◽  
Vol 44 (10) ◽  
pp. 913-919 ◽  
Author(s):  
Petra M Becker ◽  
Ulrich Stottmeister
Keyword(s):  
Carbon Source ◽  
Sole Carbon Source ◽  
Carbon Source Utilization ◽  
Community Functioning ◽  
Biolog System ◽  
Utilization Patterns ◽  
Biolog Gn ◽  
The Individual ◽  
Sole Carbon Source Utilization

Biolog community-level sole-carbon-source utilization patterns are widely applied to distinguish between the microbiota of different habitats or reveal disturbances in microbial ecosystems. Our objective was to examine whether the metabolic diversity measured in the Biolog system could be related to community functioning, thus providing more information than being merely discriminative for communities. To answer this question, we compared the percentages of specific pollutant utilizers with the percentages of the degraders of distinct general (Biolog) substrates in arbitrary samples of isolates, employing in both cases the isolate sample assay (ISA). Samples for arbitrarily selected isolates were taken from in situ enclosures situated in the anaerobic lignite-carbonization effluent Lake Schwelvollert (district of Weißenfels, Saxony-Anhalt, Germany). A different aerobic-carbonization wastewater treatment was carried out in each of the in situ enclosures. It was shown that distinct arbitrarily compiled isolate samples, which displayed similar functional patterns in terms of the degradation of pollutant-related compounds, exhibited significantly different general metabolic capacities as measured using Biolog kits. The similar pollutant-degradation potentials of the arbitrary isolates indicated that the site's substrate supply plays an important role in deciding which bacteria can become indigenous, seemingly leaving room for the otherwise varying properties of the individual community members.Key words: lignite-carbonization wastewater, ISA (isolate sample assay), sole-carbon-source utilization, Biolog, community functioning.

Carbon utilization profiles of Fusarium virguliforme isolates

2010 ◽  
Vol 56 (12) ◽  
pp. 979-986 ◽  
Author(s):  
E. Tang ◽  
C.B. Hill ◽  
G.L. Hartman
Keyword(s):  
Carbon Source ◽  
Mycelial Growth ◽  
Carbon Sources ◽  
Geographic Origin ◽  
Acid Methyl Ester ◽  
Published Data ◽  
Carbon Source Utilization ◽  
Carbon Utilization ◽  
Fusarium Virguliforme ◽  
Carbon Utilization Profiles

Fusarium virguliforme is the cause of sudden death syndrome in soybean. Physiological variability among isolates of the fungus is unknown. One way to measure physiologic variability is to analyze growth on different carbon sources. The carbon source utilization profiles of 18 F. virguliforme isolates were examined using the Biolog FF 96-well microplate, which contains 95 different carbon sources. The utilization of dextrin, d-mannitol, maltotriose, d-lactic acid methyl ester, N-acetyl-d-galactosamine, salicin, d-trehalose, and l-alanine differed significantly among isolates (P = 0.05). Carbon sources were grouped into 3 clusters based on their ability to promote growth of F. virguliforme, after calculating Euclidean distances among them. About 12% of the carbon sources promoted a high amount of mycelial growth, 39% promoted a medium amount of growth, and 49% promoted a low amount of mycelial growth; the latter was not significantly different from the water blank control. A hierarchical tree diagram was produced for the 18 isolates based on their carbon source utilization profiles using Ward’s hierarchical analysis method. Two main clusters of isolates were formed. One cluster represented greater average mycelial growth on all of the carbon sources than the other cluster. In this study, variability in carbon source utilization among F. virguliforme isolates was evident, but the results were not associated with geographic origin of the isolates, year collected, or published data on aggressiveness. Additional research is needed to determine if these carbon utilization profiles are associated with other biological characteristics, like spore germination, propagule formation, and saprophytic competitiveness.

In‐situ apparent conductivity measurements and microbial population distribution at a hydrocarbon‐contaminated site

Geophysics ◽  
2004 ◽  
Vol 69 (1) ◽  
pp. 56-63 ◽  
Author(s):  
Estella A. Atekwana ◽  
D. Dale Werkema ◽  
Joseph W. Duris ◽  
Silvia Rossbach ◽  
Eliot A. Atekwana ◽  
...  
Keyword(s):  
Microbial Degradation ◽  
Microbial Population ◽  
Population Distribution ◽  
Microbial Populations ◽  
Contaminated Site ◽  
Most Probable Number ◽  
Bulk Conductivity ◽  
Probable Number ◽  
A Site

We investigated the bulk electrical conductivity and microbial population distribution in sediments at a site contaminated with light nonaqueous‐phase liquid (LNAPL). The bulk conductivity was measured using in‐situ vertical resistivity probes; the most probable number method was used to characterize the spatial distribution of aerobic heterotrophic and oil‐degrading microbial populations. The purpose of this study was to assess if high conductivity observed at aged LNAPL‐impacted sites may be related to microbial degradation of LNAPL. The results show higher bulk conductivity coincident with LNAPL‐impacted zones, in contrast to geoelectrical models that predict lower conductivity in such zones. The highest bulk conductivity was observed to be associated with zones impacted by residual and free LNAPL. Data from bacteria enumeration from sediments close to the resistivity probes show that oil‐degrading microbes make up a larger percentage (5–55%) of the heterotrophic microbial community at depths coincident with the higher conductivity compared to ∼5% at the uncontaminated location. The coincidence of a higher percentage of oil‐degrading microbial populations in zones of higher bulk conductivity suggests that the higher conductivity in these zones may result from increased fluid conductivity related to microbial degradation of LNAPL, consistent with geochemical studies that suggest that intrinsic biodegradation is occurring at the site. The findings from this study point to the fact that biogeochemical processes accompanying biodegradation of contaminants can potentially alter geoelectrical properties of the subsurface impacted media.

scholarly journals Approaches for Eliminating Bacteria Introduced during In Situ Bioleaching of Fractured Sulfidic Ores in Deep Subsurface

2017 ◽  
Vol 262 ◽  
pp. 70-74 ◽  
Author(s):  
Hendrik Ballerstedt ◽  
Eva Pakostova ◽  
D. Barrie Johnson ◽  
Axel Schippers
Keyword(s):  
Ferric Iron ◽  
Iron Oxidation ◽  
Most Probable Number ◽  
Reduced Sulfur Compounds ◽  
Oxidation Activity ◽  
Probable Number ◽  
Horizon 2020 ◽  
Cell Counts ◽  
Microbial Iron Oxidation

The major objective of the EU Horizon 2020 project “BioMOre” is the technical realization of indirect in situ leaching of Kupferschiefer sandstone and black shale ore by a ferric iron lixiviant generated by a mixed culture of autotrophic, acidophilic, iron-oxidizing bacteria and archaea in a ferric iron-generating bioreactor (FIGB). These organisms could colonize the deeply buried geological formations even under anaerobic conditions as most are able to grow by coupling the reduction of ferric iron to the oxidation of reduced sulfur compounds in the absence of oxygen. Development of an inhibition protocol to eliminate these allochthonous microbial bioreactor populations subsequent to the completion of in situ bioleaching was therefore investigated. Column bioleaching experiments using a laboratory-scale FIGB confirmed not only that metals were solubilised from both the sandstone and shale ores, but also that significant numbers of bacteria were released from the FIGB. The efficacy of 13 different chemical compounds in inhibiting microbial iron oxidation has been tested at different concentrations in shake flask and FIGB-coupled columns. Iron-oxidation activity, microcalorimetrically-determined activity and ATP measurements, in combination with microscopic cell counts and biomolecular analysis (T-RFLP, qPCR), plate counts and most-probable-number (MPN), were used to monitor the inhibiting effects on the acidophiles. Complete inhibition of metabolic activity of iron-oxidizing acidophiles was achieved in the presence of 0.4 mM formate, 300 mM chloride, 100 mM nitrate, 10 mM of primary C6 to C8 alcohols, 100 mM 1-butanol, 100 mM 1-pentanol, 0.1 mM SDS or 0.35 mM benzoic acid. No inhibition was found for 0.6 mM acetic acid and 200 mM methanol. Based on these results a recipe for the chemical composition of the “decommissioning solution” is proposed.

Abundance of culturable versus viableEscherichia coliin freshwater

2009 ◽  
Vol 55 (7) ◽  
pp. 905-909 ◽  
Author(s):  
Pierre Servais ◽  
Josué Prats ◽  
Julien Passerat ◽  
Tamara Garcia-Armisen
Keyword(s):  
Fluorescent In Situ Hybridization ◽  
Culture Media ◽  
Large Fraction ◽  
Viable Count ◽  
Solar Irradiation ◽  
Most Probable Number ◽  
High Concentration ◽  
Probable Number ◽  
E Coli

Approved methods traditionally used for Escherichia coli enumeration in waters are culture-based. However, these methods can underestimate the E. coli abundance in aquatic systems because they do not take into account cells that remain viable but have lost the ability to grow in or on culture media. We investigated, in freshwater samples, the abundance of (i) culturable E. coli, enumerated by the most probable number microplate method and (ii) viable E. coli, estimated using a procedure called DVC–FISH, which couples fluorescent in situ hybridization (FISH) and a viability testing technique (direct viable count (DVC)). The ratio of culturable to viable E. coli was close to 1 in highly contaminated waters (samples with a high concentration of culturable E. coli), but decreased drastically for weakly contaminated samples. This indicates a large fraction of viable but nonculturable (VBNC) E. coli in the latter samples. Microcosm experiments showed that some environmental factors, such as nutrient scarcity and solar irradiation, could lead to the presence of a high proportion of VBNC E. coli.

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