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V Andreoni

Publications and source records attributed to V Andreoni.

14 recordsLinked to original sources
PubMed2004

Bacterial communities and enzyme activities of PAHs polluted soils.

Three soils (i.e. a Belgian soil, B-BT, a German soil, G, and an Italian agricultural soil, I-BT) with different properties and hydrocarbon-pollution history with regard to their potential to degrade phenanthrene were investigated. A chemical and microbiological evaluation of soils was done using measurements of routine chemical properties, bacterial counts and several enzyme activities. The three soils showed different levels of polycyclic aromatic hydrocarbons (PAHs), being their contamination strictly associated to their pollution history. High values of enzyme activities and culturable heterotrophic bacteria were detected in the soil with no or negligible presence of organic pollutants. Genetic diversity of soil samples and enrichment cultures was measured as bands on denaturing gradient gel electrophoresis (DGGE) of amplified 16S rDNA sequences from the soil and enrichment community DNAs. When analysed by Shannon index (H'), the highest genetic biodiversity (H'=2.87) was found in the Belgian soil B-BT with a medium-term exposition to PAHs and the poorest biodiversity (H'=0.85) in the German soil with a long-term exposition to alkanes and PAHs and where absence, or lower levels of enzyme activities were measured. For the Italian agricultural soil I-BT, containing negligible amounts of organic pollutants but the highest Cu content, a Shannon index=2.13 was found. The enrichment of four mixed cultures capable of degrading solid phenanthrene in batch liquid systems was also studied. Phenanthrene degradation rates in batch systems were culture-dependent, and simple (one-slope) and complex (two-slope) kinetic behaviours were observed. The presence of common bands of microbial species in the cultures and in the native soil DNA indicated that those strains could be potential in situ phenanthrene degraders. Consistent with this assumption are the decrease of PAH and phenanthrene contents of Belgian soil B-BT and the isolation of phenanthrene-degrading bacteria. From the fastest phenanthrene-degrading culture C(B-BT), representative strains were identified as Achromobacter xylosoxidans (100%), Methylobacterium sp. (99%), Rhizobium galegae (99%), Rhodococcus aetherovorans (100%), Stenotrophomonas acidaminiphila (100%), Alcaligenes sp. (99%) and Aquamicrobium defluvium (100%). DGGE-profiles of culture C(B-BT) showed bands attributable to Rhodococcus, Achromobacter, Methylobacterium rhizobium, Alcaligenes and Aquamicrobium. The isolation of Rhodococcus aetherovorans and Methylobacterium sp. can be consistent with the hypothesis that different phenanthrene-degrading strategies, cell surface properties, or the presence of xenobiotic-specific membrane carriers could play a role in the uptake/degradation of solid phenanthrene.

Bacteria↗
PubMed2003

Intrinsic bioremediability of an aromatic hydrocarbon-polluted groundwater: diversity of bacterial population and toluene monoxygenase genes.

The functional and phylogenetic biodiversity of bacterial communities in a benzene, toluene, ethylbenzene and xylene (BTEX)-polluted groundwater was analysed. To evaluate the feasibility of using an air sparging treatment to enhance bacterial degradative capabilities, the presence of degrading microorganisms was monitored. The amplification of gene fragments corresponding to toluene monooxygenase (tmo), catechol 1,2-dioxygenase, catechol 2,3-dioxygenase and toluene dioxygenase genes in DNA extracted directly from the groundwater samples was associated with the presence of indigenous degrading bacteria. Five months of air injection reduced species diversity in the cultivable community (as calculated by the Shannon-Weaver index), while little change was noted in the degree of biodiversity in the total bacterial community, as characterised by denaturing gradient gel electrophoresis (DGGE) analysis. BTEX-degrading strains belonged to the genera Pseudomonas, Microbacterium, Azoarcus, Mycobacterium and Bradyrhizobium. The degrading capacities of three strains in batch liquid cultures were also studied. In some of these microorganisms different pathways for toluene degradation seemed to operate simultaneously. Pseudomonas strains of the P24 operational taxonomic unit, able to grow only on catechol and not on BTEX, were the most abundant, and were present in the groundwater community at all stages of treatment, as evidenced both by cultivation approaches and by DGGE profiles. The presence of different tmo-like genes in phylogenetically distant strains of Pseudomonas, Mycobacterium and Bradyrhizobium suggested recent horizontal gene transfer in the groundwater.

Actinomycetales↗
PubMed2002

Survival and naphthalene-degrading activity of Rhodococcus sp. strain 1BN in soil microcosms.

AIMS: The survival and activity of Rhodococcus sp. strain 1BN, inoculated into naphthalene-contaminated sandy-loam soil microcosms, were studied using classical and molecular methods. METHODS AND RESULTS: The naphthalene-degrading activity of 1BN in microcosms was examined through viable counts, CO2 production and naphthalene consumption, while its survival after inoculation was monitored by detecting the contemporary presence of alkane and naphthalene degradative genes and by analysing the 16S rDNA specific restriction profile. The inoculation of 1BN did not significantly enhance naphthalene degradation in the naphthalene-contaminated native soil, where 1BN maintained its catabolic activity also when in the presence of indigenous microflora. Instead the rate of naphthalene degradation by the inoculated 1BN was greater in sterile naphthalene-contaminated soil. The level of 1BN was only slightly higher after inoculation regardless of whether indigenous naphthalene-degrading bacteria were present or not and 1BN remained viable even when the substrate was depleted. CONCLUSIONS: This study documents the colonization and growth of 1BN in a non-sterile, naphthalene-added, sandy-loam soil having an active indigenous naphthalene-degrading population. SIGNIFICANCE AND IMPACT OF THE STUDY: An active and well-established naphthalene-degrading bacterial population in the native soil did not hamper the survival of the introduced 1BN that, through its activity, enhanced the mineralization rate of naphthalene.

Cytochrome P-450 CYP4A↗
PubMed2000

Distribution of catabolic pathways in some hydrocarbon-degrading bacteria from a subsurface polluted soil.

Enrichment cultures on naphtha solvent were used to select aromatic hydrocarbon-degrading bacteria from a BTEX (benzene, toluene, ethylbenzene, xylene)-contaminated subsoil obtained from beneath a paint factory located in Milan, Italy. Fifteen isolated strains were studied for their different biodegradative capacities. Among these, 13 were able to grow on naphtha solvent. Ten were identified as Pseudomonas putida and three as Pseudomonas aureofaciens. Two other degraders were identified as Pseudomonas aeruginosa and Alcaligenes xylosoxidans subsp. denitrificans. Further molecular characterization of the isolates was carried out by randomly amplified polymorphic DNA analysis to ascertain that all the studied strains belonged to different haplotypes. The isolates were characterized for the presence of genes encoding for toluene dioxygenase, xylene monooxygenase and catechol 2,3-dioxygenase by polymerase chain reaction analysis and by Southern analysis. P. putida strain CM23, which showed homology with xylA,M, xylE and todC1C2BA genes, possessed multiple pathways which enabled the strain to grow on benzene, toluene and m-xylene.

Alcaligenes↗
PubMed2000

Evolution of a degradative bacterial consortium during the enrichment of naphtha solvent.

A microbial mixed culture able to degrade naphtha solvent, a model of hydrocarbon aromatic mixture, was isolated from a hydrocarbon-polluted soil. Composition of the population was monitored by phenotypic and molecular methods applied on soil DNA, on whole enrichment culture DNA, and on 85 isolated strains. Strains were characterized for their 16S rDNA restriction profiles and for their random amplified polymorphic DNA profiles. Catabolic capabilities were monitored by phenotypic traits and by PCR assays for the presence of the catabolic genes methyl mono-oxygenase ( xylA, M), catechol 2,3 dioxygenase (xylE) and toluene dioxygenase (todC1) of TOL and TOD pathways. Different haplotypes belonging to Pseudomonas putida, Ps. aureofaciens and Ps. aeruginosa were found to degrade aromatic compounds and naphtha solvent. The intrinsic catabolic activity of the microbial population of the polluted site was detected by PCR amplification of the xylE gene directly from soil DNA.

Bacteria↗
PubMed2000

Detection of genes for alkane and naphthalene catabolism in Rhodococcus sp. strain 1BN.

Rhodococcus sp. 1BN was isolated from a contaminated site and showed various biodegradative capabilities. Besides naphthalene, strain 1BN degraded medium- (C6) and long-chain alkanes (C16-C28), benzene and toluene, alone or when the hydrocarbons were mixed in equal proportions. The nucleotide sequence of an alk polymerase chain reaction (PCR) fragment revealed a 59% nucleotide homology to the Pseudomonas oleovorans alkB gene. The nar fragments were highly homologous to genes coding for large and small subunits of cis-naphthalene 1,2-dioxygenase (narAa and narAb) and to cis-naphthalene dihydrodiol dehydrogenase (narB) from other rhodococci. The oxidation of indene to cis-(1S,2R)-1,2-dihydroxyindan by toluene-induced cells allows to hypothesize that strain 1BN also carries a toluene dioxygenase-like system.

Alkanes↗
PubMed1998

Degradation of 2,4,6-trichlorophenol by a specialized organism and by indigenous soil microflora: bioaugmentation and self-remediability for soil restoration.

A selected mixed culture and a strain of Alcaligenes eutrophus TCP were able to totally degrade 2,4,6,-TCP with stoichiometric release of Cl-. In cultures of Alc. eutrophus TCP, a dioxygenated dichlorinated metabolite was detected after 48 h of incubation. Experiments conducted with soil microcosms gave evidence that: the degradative process had a biotic nature and was accompanied by microbial growth; the soil used presented an intrinsic degradative capacity versus 2,4,6-TCP; the specialized organism used as inoculum was effective in degrading 2,4,6-TCP in a short time. These results could be utilized for the adoption of appropriate remediation techniques for contaminated soil.

Alcaligenes↗
PubMed1995

Project management: putting continuous quality improvement theory into practice.

A growing number of projects required by a changing national health care environment and an increased awareness of continuous quality improvement methodologies provided the impetus for the department of nursing at a 265-bed academic children's hospital to develop a standardized project management approach. The article describes how the project management process unfolded from beginning to end utilizing the plan-do-check-act cycle.

Chicago↗
PubMed1994

Cometabolic degradation of acifluorfen by a mixed microbial culture.

Laboratory experiments were conducted to study the degradation of acifluorfen 5-[2-chloro-4-(trifluoromethyl)-phenoxyl]-2-nitrobenzoic acid by a mixed microbial population. Concentrations of acifluorfen up to 100 mg/l had no inhibitory effect on the growth of microbial culture. The microorganisms degraded acifluorfen through a cometabolic process in presence of 2-nitrobenzoate. The degradation rate of acifluorfen, determined by liquid chromatography analysis in batch cultures incubated under oxygen-limited conditions were compared. The degradation was slower under oxygen than oxygen-limited conditions. Aminoacifluorfen was produced in both conditions.

Acetates↗
PubMed1993

Microbial metabolism of fluazifop-butyl.

A microbial mixed culture able to grow on fluazifop-butyl and fluazifop was isolated. Fluazifop degradation by this microbial population was studied either when the herbicide was applied as the sole carbon source or in the presence of a second carbon source (sodium acetate or sodium propionate). The degradation rate was enhanced by sodium propionate. The degradation was found to be stereoselective. The S-enantiomer of fluazifop was degraded at a much higher rate than the R-enantiomer. Fluazifop disappearance was accompanied by formation of three metabolites which were identified by UV, IR, MS and NMR analyses. The metabolites were shown to be: 4-(5-trifluoromethyl-2-pyridyl)oxyphenol, 5-trifluoromethyl-2- hydroxypyridine and 2-(5-trifluoro-methyl pyridyl)hydroxy acetate.

Acetates↗
PubMed1990

Biotransformation of alkyl and aryl carbonates. Microbial degradation.

An enriched mixed culture was successfully grown on model alkyl and aryl carbonates. These compounds were degraded by microorganisms at different rates. P-Chlorophenyl-2-octyl carbonate and p-nitrobenzyl-2-octyl carbonate were metabolized through the formation of p-chlorophenol and p-nitrobenzyl alcohol respectively. A strain of Acinetobacter calcoaceticus isolated from the mixed culture utilized phenyl-2-octyl carbonate by an intracellular hydrolase to phenol and 2-octanol which were further metabolized.

Acinetobacter↗
PubMed1986

Comparative analysis of different Pseudomonas strains that degrade cinnamic acid.

Strains of Pseudomonas stutzeri (CINNS) and Pseudomonas putida (CINNP and CINNW) isolated from soil with cinnamic acid as the sole carbon source were found to be simultaneously adapted to grow on phenylpropionic and p-hydroxybenzoic acids. In cinnamic acid-grown cultures, phenylpropionic acid was isolated. A catabolic plasmid of approximately equal to 75 kilobase pairs encoding the metabolism of cinnamic acid was found in strains CINNP and CINNS.

Biodegradation, Environmental↗
PubMed1983

The microbial oxygenation of the benzylisoquinoline alkaloid laudanosine.

The microbial transformation of the benzylisoquinoline alkaloid laudanosine by a strain of Pseudomonas putida gives a metabolite in which O-demethylation of 1 methoxyl group of ring C, and introduction of 1 ketonic oxygen at C9 and 1 phenolic oxygen at ring C have occurred. Also, O-methylcoripalline is formed in this transformation.

Biotransformation↗