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1.
Appl Microbiol Biotechnol ; 63(2): 194-9, 2003 Dec.
Article in English | MEDLINE | ID: mdl-12827325

ABSTRACT

Soil samples were taken from areas of low pH (2.5-3.5) surrounding an outdoor coal storage pile. These samples were added to medium with naphthalene as the sole carbon source to enrich for organisms capable of degrading polycyclic aromatic hydrocarbons (PAH) at low pH. Five such bacterial strains were isolated. Sequencing of the 16S rDNA showed them to be members of the genera Clavibacter, Arthrobacter and Acidocella. These organisms were all capable of growth with naphthalene as a sole carbon source at low pH. The genes nahAc, nahAd, phnAc, nahH, xylE or GST, which are known to be associated with PAH degradation were not detected. Isolate 10, the Acidocella strain, tolerated high levels of mercury. PCR amplification and sequencing of genes from the mer operon from isolate 10 DNA suggested that mercury is transported into the bacterial cell and subsequently detoxified since the enzymes encoded by genes in this operon are involved in these processes.


Subject(s)
Acetobacteraceae/isolation & purification , Actinomycetales/isolation & purification , Mercury/pharmacology , Naphthalenes/metabolism , Soil Microbiology , Acetobacteraceae/classification , Acetobacteraceae/drug effects , Acetobacteraceae/metabolism , Actinomycetales/classification , Actinomycetales/drug effects , Actinomycetales/metabolism , Bacterial Proteins/genetics , DNA, Ribosomal/analysis , Drug Resistance, Bacterial , Hydrogen-Ion Concentration , Molecular Sequence Data , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA
2.
Environ Sci Technol ; 35(19): 3816-22, 2001 Oct 01.
Article in English | MEDLINE | ID: mdl-11642438

ABSTRACT

Automobile catalytic converters are dispersing platinum-group elements (PGEs) Rh, Pt, and Pd into the environment (1-3). This paper represents the first detailed study to assess the PGE content of soils and grasses from U.S. roadsides. These soils were analyzed using cation exchange pretreatment and ultrasonic nebulizer-ICP-MS (4). Highway and several urban sites showed Pt abundances of 64-73 ng/g immediately adjacent to the roadside, with corresponding Pd and Rh abundances of 18-31 ng/g and 3-7 ng/g, respectively. All Pt and most Pd and Rh abundances are statistically above local background soil values. Platinum, Rd, and Rh show positive correlations with traffic-related elements (Ni, Cu, Zn, and Pb) but no correlations with nontraffic-related elements (Y, Ga). Iridium and Ru show no correlations with any of these trace elements. These PGE abundances are comparable to European studies (5-7) and are approaching concentrations that would be economically viable to recover. This study also demonstrates transport of Pt statistically above background more than 50 m from the roadside. Further study is necessary to see how mobile the PGEs are in roadside environments, but these initial data indicate only Pt is taken up by plants.


Subject(s)
Air Pollutants/analysis , Lead/analysis , Platinum/analysis , Poaceae/chemistry , Rhodium/analysis , Soil Pollutants/analysis , Vehicle Emissions/analysis , Air Pollutants/pharmacokinetics , Environmental Monitoring , Lead/pharmacokinetics , Platinum/pharmacokinetics , Rhodium/pharmacokinetics , Soil Pollutants/pharmacokinetics , Tissue Distribution
3.
Environ Sci Technol ; 35(18): 3786-91, 2001 Sep 15.
Article in English | MEDLINE | ID: mdl-11783660

ABSTRACT

Pollution of the environment with toxic metals is widespread and often involves large volumes of wastewater. Remediation strategies must be designed to support high throughput while keeping costs to a minimum. Biosorption is presented as an alternative to traditional physicochemical means for removing toxic metals from wastewater. We have investigated the metal binding qualities of two biomass byproducts that are commercially available in quantity and at low cost, namely "spillage", a dried yeast and plant mixture from the production of ethanol from corn, and ground corn cobs used in animal feeds. The biomass materials effectively removed toxic metals, such as Cu, Cs, Mo, Ni, Pb, and Zn, even in the presence of competing metals likely to be found in sulfide mine tailing ponds. The effectiveness of these biosorbents was demonstrated using samples from the Berkeley Pit in Montana. Investigations included column chromatography and slurry systems, and linear distribution coefficients are presented. X-ray spectroscopy was used to identify the binding sites for metals adsorbed to the spillage material. The results of our experiments demonstrate that the biosorption of metals from wastewaters using biomass byproducts is a viable and cost-effective technology that should be included in process evaluations.


Subject(s)
Conservation of Natural Resources , Metals, Heavy/chemistry , Waste Disposal, Fluid/methods , Adsorption , Animal Feed , Biodegradation, Environmental , Biomass , Plants , Water Pollution/prevention & control , Yeasts
5.
Appl Microbiol Biotechnol ; 47(1): 69-72, 1997 Jan.
Article in English | MEDLINE | ID: mdl-9035411

ABSTRACT

Three pure bacterial cultures degrading methyl t-butyl ether (MTBE) were isolated from activated sludge and fruit of the Gingko tree. They have been classified as belonging to the genuses Methylobacterium, Rhodococcus, and Arthrobacter. These cultures degraded 60 ppm MTBE in 1-2 weeks of incubation at 23-25 degrees C. The growth of the isolates on MTBE as sole carbon source is very slow compared with growth on nutrient-rich medium. Uniformly-labeled [14C]MTBE was used to determine 14CO2 evolution. Within 7 days of incubation, about 8% of the initial radioactivity was evolved as 14CO2. These strains also grow on t-butanol, butyl formate, isopropanol, acetone and pyruvate as carbon sources. The presence of these compounds in combination with MTBE decreased the degradation of MTBE. The cultures pregrown on pyruvate resulted in a reduction in 14CO2 evolution from [14C]MTBE. The availability of pure cultures will allow the determination of the pathway intermediates and the rate-limiting steps in the degradation of MTBE.


Subject(s)
Environmental Pollutants/metabolism , Gram-Negative Aerobic Bacteria/metabolism , Gram-Positive Bacteria/metabolism , Methyl Ethers/metabolism , Arthrobacter/metabolism , Biodegradation, Environmental , Gram-Negative Aerobic Bacteria/classification , Gram-Positive Bacteria/classification , Rhodococcus/metabolism , Trees/microbiology
6.
Arch Environ Contam Toxicol ; 32(1): 94-8, 1997 Jan.
Article in English | MEDLINE | ID: mdl-9002439

ABSTRACT

In earlier studies (Boopathy et al. 1994a, 1994b), soil bacteria present in a TNT-contaminated site removed 2,4,6-trinitrotoluene (TNT). In this study the optimum conditions for the most efficient removal of TNT is discussed. The results suggest that the soil bacterial consortium has an optimal pH range of 6-7. Maximum growth was observed at pH 7. However, the TNT removal rate was higher at pH 6. Studies of the effects of temperature showed that the bacterial consortium had maximum metabolic activity at 20 to 22 degrees C (ambient temperature). At a higher temperature (37 degrees C) the TNT removal rate dropped significantly. The consortium could not use TNT as a nitrogen source but required the addition of ammonium. Optimal growth occurred with 0.25 g/L of ammonium chloride. Growing cells removed TNT significantly faster rates than resting cells or cell-free extract. The operation of soil slurry reactors with the optimal conditions suggested that TNT can be removed effectively from the contaminated sites. These environmental conditions established as optimal can be used to improve the efficiency of large-scale soil slurry reactors for the treatment of soil contaminated with TNT.


Subject(s)
Soil Microbiology , Soil Pollutants/metabolism , Trinitrotoluene/metabolism , Biodegradation, Environmental , Cell Division/drug effects , Chromatography, High Pressure Liquid , Hydrogen-Ion Concentration , Pseudomonas/cytology , Pseudomonas/metabolism , Temperature , Trinitrotoluene/toxicity
7.
Appl Environ Microbiol ; 61(11): 3981-5, 1995 Nov.
Article in English | MEDLINE | ID: mdl-8526513

ABSTRACT

A modified freeze-thaw method in combination with reverse transcriptase PCR was developed for monitoring gene expression in activated sludge. The sensitivity of the methodology was determined by inoculating non-sterile activated sludge samples with 3-chlorobenzoate-degrading Pseudomonas putida PPO301(pRO103), which contains the catabolic tfdB gene. tfdB mRNA was detected in 10 mg of activated sludge inoculated with 10(4) CFU of the target organism. This technique was subsequently utilized to analyze the in situ expression of the catabolic dmpN gene in a sequencing batch reactor (SBR) bioaugmented with phenol-degrading P. putida ATCC 11172. Greatest dmpN expression was observed 15 min after maximum phenol concentration was reached in the reactor and 15 min after the start of aeration. Decreased phenol concentrations in the reactor corresponded to reduced levels of dmpN expression, although low levels of dmpN mRNA were observed throughout the SBR cycle. These results indicate that concentration of phenol in the reactor and the onset of aeration stimulated transcriptional activity of the dmpN gene. The information obtained from this study can be used to alter SBR operational strategies so as to lead to more effective bioaugmentation practices.


Subject(s)
Genes, Bacterial , Phenols/metabolism , Polymerase Chain Reaction/methods , Pseudomonas putida/genetics , Pseudomonas putida/metabolism , Base Sequence , Biodegradation, Environmental , Biotechnology , DNA Primers/genetics , DNA, Bacterial/genetics , Densitometry , Environmental Pollutants/metabolism , Gene Expression , Molecular Sequence Data , Phenol , Polymerase Chain Reaction/statistics & numerical data , RNA-Directed DNA Polymerase , Sensitivity and Specificity
8.
Can J Microbiol ; 40(4): 273-8, 1994 Apr.
Article in English | MEDLINE | ID: mdl-8039051

ABSTRACT

A mesophilic, irregular coccoid methanogen, which shows close resemblance to Methanococcus sp., was isolated from a sediment sample of St. Joseph Lake located in the University of Notre Dame campus. Formate or hydrogen plus carbon dioxide served as substrate for methanogenesis in a mineral salt medium. This organism was studied for its ability to metabolize 2,4,6-trinitrotoluene (TNT). The result showed that this isolate could transform 100 ppm of TNT within 40-60 days of incubation at 30 degrees C. The main intermediate produced was 2,4-diamino-6-nitrotoluene. The TNT transformation rates were higher in cells grown in hydrogen plus carbon dioxide than in cells grown in formate. The isolate did not use acetate and methanol as sole source of carbon and energy. The organism had an optimal pH range of 6.8-7.2. The optimal growth conditions for this isolate are described.


Subject(s)
Methanococcus/metabolism , Trinitrotoluene/pharmacokinetics , Water Microbiology , Biotransformation , Fresh Water , Microscopy, Electron, Scanning , Toluidines/metabolism
9.
Can J Microbiol ; 39(4): 430-3, 1993 Apr.
Article in English | MEDLINE | ID: mdl-8500012

ABSTRACT

A sulfate-reducing bacterium, Desulfovibrio sp. (B strain), isolated from a continuous anaerobic digester, used various nitroaromatic compounds such as 2,4-dinitrophenol, 2,4-dinitrotoluene, and 2,6-dinitrotoluene as sole nitrogen sources for growth and also used these compounds as electron acceptors in the absence of sulfate in the culture medium. More than 60% of the nitroaromatics were transformed within 6 days of incubation. The organism also used aniline as sole nitrogen source, but not as an electron acceptor. Desulfovibrio sp. (B strain) did not use nitroaromatics as sole source of carbon and energy. The nitro groups in the aromatic ring were reduced and reductively deaminated to ammonia, which was used as nitrogen source, leaving the aromatic ring intact. Even though this organism did not degrade the nitroaromatics completely, it may be useful in degrading nitroaromatics in contaminated soil and water containing other aromatic degraders in a syntrophic culture system under anaerobic conditions.


Subject(s)
Ammonia/metabolism , Aniline Compounds/metabolism , Desulfovibrio/metabolism , Dinitrobenzenes/metabolism , Dinitrophenols/metabolism , 2,4-Dinitrophenol , Biotransformation , Desulfovibrio/growth & development
10.
Curr Microbiol ; 25(4): 235-41, 1992 Oct.
Article in English | MEDLINE | ID: mdl-1368976

ABSTRACT

A sulfate-reducing bacterium (SRB), Desulfovibrio sp. (B strain), isolated from a continuous anaerobic digester (Boopathy and Daniels, Current Microbiology, 23:327-332, 1991) was found to use 2,4,6-trinitrotoluene (TNT) as sole nitrogen source. This bacterium also used nitrate, nitrite, and ammonium as nitrogen source. A long lag period was noticed when TNT or nitrite was used as nitrogen source. Nitrate, nitrite and TNT also served as electron acceptor in the absence of sulfate for this bacterium. Under nitrogen-limiting condition, 100% removal of TNT was observed within 8 days of incubation. The main intermediate observed was diaminonitrotoluene, which was further converted to toluene via triaminotoluene by reductive deamination process. Under nitrogen-rich conditions (presence of ammonium), TNT was converted to diaminonitrotoluene, and toluene was not produced. This isolate did not degrade TNT all the way to CO2. This study demonstrated the possibility of using this isolate to decontaminate the soil and water contaminated with TNT under anaerobic conditions.


Subject(s)
Desulfovibrio/metabolism , Nitrogen/metabolism , Trinitrotoluene/metabolism , Anaerobiosis , Desulfovibrio/growth & development , Kinetics , Trinitrotoluene/isolation & purification
11.
J Bacteriol ; 156(1): 434-6, 1983 Oct.
Article in English | MEDLINE | ID: mdl-6352686

ABSTRACT

RP1, a broad-host-range incompatibility group P1 plasmid specifying multiple drug resistances, has been transferred into the chemolithotrophic bacterium Thiobacillus neapolitanus. The ability of T. neapolitanus to receive, express, and transmit RP1-encoded antibiotic resistances was examined. The data show that this obligate chemolithotroph can accept, replicate, and express heterologous plasmid DNA from a heterotrophic bacterium.


Subject(s)
Conjugation, Genetic , Escherichia coli/genetics , R Factors , Thiobacillus/genetics , Anti-Bacterial Agents/pharmacology , Thiobacillus/drug effects
12.
J Interferon Res ; 2(2): 187-94, 1982.
Article in English | MEDLINE | ID: mdl-6181176

ABSTRACT

Old tuberculin (OT) does not induce interferon in mice while OT associated with liposomes made to contain a positive charge (L+:OT) induced high titers of circulating interferon. Since OT associated with neutral or negatively charged liposomes did not induce interferon, the positive charge of the liposome is therefore important. Dose-response studies indicated the optimum induced contains 50 mg OT. Kinetic studies indicated that the peak interferon response occurred 4 hours after induction with L+:OT. Sonication in the preparation of L+:OT was also important since mixing of sonicated positively charged liposome (L+s) with sonicated OT (OTs) induced interferon titers 10-fold less than L+:OT prepared by sonication of OT and liposomes together. L+s or OTs injected alone did not induce interferon. L+s injected before or after OTs did not induce interferon. Interferon induced by L+:OT was characterized of virus-induced interferon by the following criteria: (a) stable at pH 2, (b) inactivated by trypsin, (c) inactivated at 56 degrees C for 30 min, and (d) neutralized by rabbit antisera to mouse L cell interferon. Thus, the association of a noninducer or a weak interferon inducer with liposomes may result in potent interferon inducers. Many nontoxic, low molecular weight agents may thus be of value by association with liposomes to induce interferon for antiviral and antitumor therapy.


Subject(s)
Interferon Inducers , Liposomes , Tuberculin/immunology , Animals , Female , Interferons/biosynthesis , Male , Mice , Sonication
14.
Biochim Biophys Acta ; 466(1): 160-75, 1977 Apr 01.
Article in English | MEDLINE | ID: mdl-322711

ABSTRACT

Membrane-defective mutants of Escherichia coli J5 were isolated on the basis of supersensitivity to the antibiotic novobiocin. These mutants display an increased sensitivity to a wide range of antibiotics and to several dyes and detergents. In addition, several mutants leak the periplasmic enzymes, alkyline phosphatase and ribonuclease. This evidence indicates an outer membrane defect in these mutants. The inner and outer membranes of one mutant were separated and subjected to compositional analysis. A deficiency in galactose containing lipopolysaccharide in the outer membrane of the mutant was observed. Two possible causes of this deficiency were examined and discounted: defective galactose uptake into the cell, and defective translocation of lipopolysaccharide from the inner membrane. Extraction and chemical analysis of mutant and wild type lipopolysaccharides suggests that the mutant is defective in the enzyme which transfers glucose to the growing lipopolysaccharide core, UDPglucose transferase. Thus, the mutant's deficiency in galactose-containing lipopolysaccharide can be ascribed to the fact that addition of glucose to the lipopolysaccharide core is a prerequisite for galactose addition. The physiological implications of this alteration are discussed.


Subject(s)
Cell Membrane/metabolism , Escherichia coli/metabolism , Lipopolysaccharides , Polysaccharides, Bacterial/biosynthesis , Biological Transport, Active , Carbohydrates/analysis , Cell Fractionation , Cell Membrane/drug effects , Centrifugation, Density Gradient , Escherichia coli/drug effects , Galactosides/metabolism , Heptoses/metabolism , Kinetics , Lipopolysaccharides/biosynthesis , Membrane Transport Proteins/metabolism , Molecular Conformation , Mutation , Novobiocin/pharmacology
16.
Biochim Biophys Acta ; 448(3): 451-9, 1976 Oct 19.
Article in English | MEDLINE | ID: mdl-184839

ABSTRACT

The fluorescent probes pyrene, pyrene butyric acid and N-phenyl 1-naphthylamine have been used to investigate the changes that accompany in vitro transformation of a baby hamster kidney cell line using Rous sarcoma virus. The fluorescent probes which reside in the membrane were used to compare the changes in microviscosity and polarity of the membranes of normal cells with two transformed cell lines. The spectrofluorimetric data indicate that following transformation the probe N-phenyl 1-naphthylamine resides in a more polar environment. However, using the probe pyrene, the yield of excimer indicates decreased mobility of this probe in the membrane of transformed cells. The data also indicate differences between the two transformed cell lines. Laser photolysis was used to study the lifetime of the pyrene probes and the quenching of the pyrene fluorescence in the membrane by several different quenching molecules. The data indicate differences between the three cell lines and suggest that transformation decreases movement within the membrane.


Subject(s)
Avian Sarcoma Viruses , Cell Transformation, Neoplastic , 1-Naphthylamine/analogs & derivatives , Cell Line , Cell Membrane/ultrastructure , Fluorescent Dyes , Lasers , Photolysis , Pyrenes , Spectrometry, Fluorescence , Viscosity
17.
Biochim Biophys Acta ; 426(4): 711-22, 1976 Apr 05.
Article in English | MEDLINE | ID: mdl-769828

ABSTRACT

Pyrene and several derivatives of pyrene are used to investigate photo-induced kinetic processes in whole cells and membranes extracted from Escherichia coli. A mutant of E. coli was used which, under appropriate growth conditions, produced a complete or incomplete lipopolysaccharide in the outer membrane. The pyrene derivatives used were: pyrene sulfonic acid, pyrene butyric acid and the ester of pyrene butyric acid and 10-hydroxydecanoic acid. The pyrene chromophore was excited by the ultraviolet pulse from a Q switch, frequency-doubled, ruby laser. The lifetimes of the pyrene fluorescence in the presence of the quenchers O2, thallous ion (T1+), I-and CH3NO2 were measured and tabulated as second order rate constants. For the most part the quenching rate constants were much lower than the corresponding values observed in simple nonviscous solution, e.g. ethanol. This is interpreted as being due to the location of the probe within the membrane. The membrane inhibits the movement of the quenchers to the excited state. Cell membranes containing complete lipopolysaccharide showed significantly lower quenching rates for the probes pyrene and pyrene sulfonic acid than cell membranes with incomplete lipopolysaccharide. From an amalysis of the kinetic data it is suggested that pyrene and pyrene sulfonic acid are located near and under lipopolysaccharide and close to membrane proteins. On the other hand, no effect of lipopolysaccharide composition was observed for the probes pyrene butyric acid and pyrene butyroyl decanoic acid. This may suggest that these probes are located primarily in the lipid part of the membrane. A simple model for the outer membrane of E. coli is suggested that accounts for the observed laser-induced kinetic processes.


Subject(s)
Cell Membrane/metabolism , Escherichia coli/metabolism , Pyrenes/metabolism , Biological Transport , Cell Membrane/ultrastructure , Kinetics , Lasers , Lipopolysaccharides/metabolism , Models, Biological , Polysaccharides, Bacterial/metabolism , Structure-Activity Relationship
18.
J Bacteriol ; 126(1): 467-77, 1976 Apr.
Article in English | MEDLINE | ID: mdl-770432

ABSTRACT

A mutant of Escherichia coli that lacks uridine 5'-diphosphate galactose-4-epimerase makes lipopolysaccharide with less carbohydrate than the parent, unless galactose is present during growth. Carbohydrate is dense, and the outer membrane, which contains lipopolysaccharide, was found to be denser when isolated from cells grown with galactose then when galactose was omitted. Cells given galactose after growth in its absence rapidly formed dense regions within the outer membrane that disappeared when galactose was removed. These results indicate that lipopolysaccharide enters the outer membrane nonrandomly at a minimum of 10 to 22 discrete "insertion points." Isopycnic centrifugation provides a method for isolating these regions.


Subject(s)
Escherichia coli/metabolism , Lipopolysaccharides/metabolism , Polysaccharides, Bacterial/metabolism , Carbohydrate Epimerases/biosynthesis , Cell Membrane/metabolism , Cell Membrane/ultrastructure , Escherichia coli/enzymology , Escherichia coli/ultrastructure , Galactose/metabolism , Mutation , Subcellular Fractions
19.
Can J Microbiol ; 21(8): 1217-23, 1975 Aug.
Article in English | MEDLINE | ID: mdl-1100208

ABSTRACT

A DNA bacteriophage, designated CP13, was isolated against Escherichia coli J5, a UDP-galactose-4-epimeraseless mutant of E. coli 0111:B4. Bacteriophage CP13 appears to be specific for rough bacterial strains. Adsorption studies with E. coli J5 grown with galactose show that the bacteriophage will not adsorb when complete lipopolysaccharide is present in the cell membrane. This indicates that lipopolysaccharide may be directly or indirectly involved with the receptor site for bacteriophage CP13. The bacteriophage DNA has a G + C content of 52%.


Subject(s)
Coliphages/isolation & purification , Escherichia coli/enzymology , Isomerases/biosynthesis , Racemases and Epimerases/biosynthesis , Adsorption , Binding Sites , Coliphages/analysis , Coliphages/growth & development , Cytosine/analysis , DNA Viruses , DNA, Viral/analysis , Guanine/analysis , Lipopolysaccharides , Mutation , Polysaccharides, Bacterial , Uridine Diphosphate Galactose
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