ABSTRACT We compared and statistically evaluated the effectiveness of nine DNA extraction procedures by using frozen dried samples two silt loam soils a wetland sediment with different organic matter contents. The effects chemical extractants (sodium dodecyl sulfate [SDS], chloroform, phenol, Chelex 100, guanadinium isothiocyanate), physical disruption methods (bead mill homogenization freeze-thaw lysis), lysozyme digestion were based on yield molecular size recovered DNA. Pairwise...

This study reports improvements in two of the key steps, lysis indigenous cells and DNA purification, required for achieving a rapid nonselective protocol extracting nucleic acids directly from sodium dodecyl sulfate (SDS)-treated sediment rich organic matter. Incorporation bead-mill homogenization into extraction procedure doubled densitometrically determined yield (11.8 micrograms DNA.g [dry weight] sediment-1) relative to incorporation three cycles freezing thawing (5.2 sediment-1). The...

Microorganisms maintain the biosphere by catalyzing biogeochemical processes, including biodegradation of organic chemical pollutants. Yet seldom have responsible agents and their respective genes been identified. Here we used field-based stable isotopic probing (SIP) to discover a group bacteria for in situ metabolism an environmental pollutant, naphthalene. We released 13 C-labeled naphthalene contaminated study site trace flow pollutant carbon into naturally occurring microbial community....

Our goal was to develop a field soil biodegradation assay using 13C-labeled compounds and identify the active microorganisms by analyzing 16S rRNA genes in soil-derived DNA. approach sought minimize microbiological artifacts caused physical and/or nutritional disturbance of associated with sampling laboratory incubation. The new field-based involved release (glucose, phenol, caffeine, naphthalene) plots, installation open-bottom glass chambers that covered soil, analysis samples headspace...

Horizontal transfer of genes responsible for pollutant biodegradation may play a key role in the evolution bacterial populations and adaptation microbial communities to environmental contaminants. However, field evidence horizontal gene between microorganisms has traditionally been very difficult obtain. In this study, sequences 16S rRNA naphthalene dioxygenase iron-sulfur protein (nahAc) nine naphthalene-degrading bacteria isolated from coal tar waste-contaminated site, as well bacterium...

We report the amplification of bacterial genes from uninoculated surface and subsurface sediments by polymerase chain reaction (PCR). PCR indigenous 16S ribosomal DNA was unsuccessful when sediment containing approximately 10(7) cells.g-1 added directly to a mixture. However, 10 mg inoculated with 10(5) cells Pseudomonas putida G7, nahAc naphthalene dioxygenase gene characteristic P. G7 NAH7 plasmid detected amplification. Southern blotting product improved sensitivity 10(3) 10(4) samples...

The mineralization of 1.0 to 100 ng each four complexing compounds—oxalate, citrate, nitrilotriacetate (NTA), and EDTA—per ml was tested in media prepared accordance with equilibrium calculations by a computer program so that the H, Ca, Mg, Fe, or Al complex (chemical species) predominant. Sewage microorganisms mineralized calcium citrate more rapidly than iron, aluminum, hydrogen magnesium degraded slowest. Aluminum, hydrogen, iron oxalates were oxalate, oxalate decomposed NTA but not...

ABSTRACT The presence of a highly conserved nahAc allele among phylogenetically diverse bacteria carrying naphthalene-catabolic plasmids provided evidence for in situ horizontal gene transfer at coal tar-contaminated site (J. B. Herrick, K. G. Stuart-Keil, W. C. Ghiorse, and E. L. Madsen, Appl. Environ. Microbiol. 63:2330–2337, 1997). objective the present study was to identify characterize different-sized order determine probable mechanism situ. Filter matings between naphthalene-degrading...

Summary Laboratory incubations of coal‐tar waste‐contaminated sediment microbial communities under relatively controlled physiological conditions were used to interpret results a field‐based stable isotope probing (SIP) assay. Biodegradation activity 13 C‐benzene was examined by GC/MS determination net CO 2 production and GC headspace analysis benzene loss. Key experimental variables were: the site assays (laboratory serum‐bottle in situ field sediments), concentration (10, 36 or 200 p.p.m....

When indole was incubated under methanogenic conditions with an inoculum of sewage sludge, the chemical metabolized 10 days and temporary formation intermediate observed. The metabolite isolated by thin-layer chromatography determined to be 1,3-dihydro-2H-indol-2one (oxindole) UV spectroscopy (lambdaMAX, 247 nm) mass spectrometry (m/z, 133). methane produced (net amount) indicated nearly complete mineralization indole.

A recent article presented geochemical and microbial evidence establishing metabolic adaptation to in-situ reductive dechlorination of trichloroethene (TCE) in a fractured dolomite aquifer. This study was designed further explore site conditions populations explain previously reported enhancement by the addition pulverized laboratory microcosms. survey groundwater parameters (chlorinated ethenes, ethene, H2, CH4, DIC, DOC, δ13C values for DOC) indicated that situ ongoing an unidentified pool...

The influence of physiological and environmental factors on the accumulation oxindole during anaerobic indole metabolism was investigated by high-performance liquid chromatography. Under methanogenic conditions, temporarily converted to in stoichiometric amounts media inoculated with three freshwater sediments an organic soil. In sewage sludge, modest detected at 35 degrees C reached higher concentrations persisted longer when incubation temperature decreased from 15 C. Also, decreasing...

Abstract Naphthalene has been transported approx. 400 m via groundwater flow from buried subsurface coal tar to an organic matter‐rich seep area where the water emerges at foot of a hill in field study site. We have tested several hypotheses for explaining why naphthalene persists sediments. In aerobic laboratory flask assays, conversion 14 C‐naphthalene CO 2 occurred and was not stimulated by amendments with vitamins or inorganic nutrients. Thus, neither toxicity nor nutrient limitation...

ABSTRACT We examined transfer of naphthalene-catabolic genes from donor microorganisms native to a contaminated site site-derived, rifampin-resistant recipient bacteria unable grow on naphthalene. Horizontal gene (HGT) was demonstrated in filter matings using groundwater as donors. Two distinct but similar plasmid types, closely related pDTG1, were retrieved. In laboratory-incubated sediment matings, the addition naphthalene stimulated HGT. However, deployed recoverable vessels field (in...

Packed columns are widely used in the chemical industry such as absorption, stripping, distillation, and extraction production of e.g. organic chemicals, pharmaceuticals. Pressure loss pressure drop correlations special interest when it comes to hydrodynamic properties a column. The across column is design phase size blower drive gas stream through has be decided. loading point flooding also influenced by area operation determined from these points. This work examines four different on drop....

Field experiments utilizing randomized block designs were implemented to assess the mobility of both coal tar-derived aromatic hydrocarbons and bacteria capable metabolizing these substances at a contaminated field site. Arrays sorbent materials wrapped in fiberglass mesh fabric inserted into organic matter-rich freshwater sediments order intercept mobile chemicals carried by prevailing hydraulic gradient. Polyurethane foam plugs served as for aqueous-phase tar components while sterile sand...