Papers by Elena Tamburini
International journal of biological macromolecules, 2015
A novel biopolymer was described in the form of an extracellular polysaccharide (EPS) by Pedobact... more A novel biopolymer was described in the form of an extracellular polysaccharide (EPS) by Pedobacter sp. strain MCC-Z, a member of a bacterial genus not previously described as an emulsifier producer. The new biomolecule was extracted, purified and characterized, and its surface and emulsifying properties were evaluated. The purified bioemulsifier, named Pdb-Z, showed high emulsifying activity (E24% = 64%) and reduced the surface tension of water up to 41 mN/m with a critical micelle concentration value of 2.6 mg/mL. The chemical characterization of Pdb-Z was performed using (1)H NMR, FT-IR, HPLC/MS/MS and GC/MS. Pdb-Z was found to contain 67% of carbohydrates, consisting mainly of galactose and minor quantities of talose, 30% of lipids, being pentadecanoic acid the major lipidic constituent, and 3% of proteins. The bioemulsifier was a glycolipids-protein complex with an estimated molecular mass of 10(6)Da. Furthermore, Pdb-Z emulsified pure aliphatic and aromatic hydrocarbons as wel...
Journal of Bioenergetics and Biomembranes
Salinibacter ruber is an extremophilic bacterium able to grow in high-salts environments, such as... more Salinibacter ruber is an extremophilic bacterium able to grow in high-salts environments, such as saltern crystallizer ponds. This halophilic bacterium is red-pigmented due to the production of several carotenoids and their derivatives. Two of these pigment molecules, salinixanthin and retinal, are reported to be essential cofactors of the xanthorhodopsin, a light-driven proton pump unique to this bacterium. Here, we isolate and characterize an outer membrane porin-like protein that retains salinixanthin. The characterization by mass spectrometry identified an unknown protein whose structure, predicted by AlphaFold, consists of a 8 strands beta-barrel transmembrane organization typical of porins. The protein is found to be part of a functional network clearly involved in the outer membrane trafficking. Cryo-EM micrographs showed the shape and dimensions of a particle comparable with the ones of the predicted structure. Functional implications, with respect to the high representativi...
Journal of Microbial & Biochemical Technology, Sep 11, 2015
Journal of Molecular Evolution, Sep 1, 1998
A novel system to study the evolution of transcription signals in heterologous systems under sele... more A novel system to study the evolution of transcription signals in heterologous systems under selective starvation conditions is described. It is based on the plasmid-mediated transfer of his biosynthetic genes from Azospirillum brasilense into a heterologous Escherichia coli mutant population lacking histidine biosynthetic ability. We show that under highly selective stressful conditions, genetic changes in the donor plasmid lead to mutated sequences that are efficiently recognized as promoters by the E. coli RNA polymerase.
The residues from human environments often contain antibiotics and antibiotic resistance genes (A... more The residues from human environments often contain antibiotics and antibiotic resistance genes (ARGs) that can contaminate natural environments; the clearest consequence of that is the selection of antibiotic-resistant bacteria. The Baltic Sea is the second largest isolated brackish water reservoir on Earth, serving as a drainage area for people in 14 countries, which differ from one another in antibiotic use and sewage treatment policies. The aim of this study was to characterize the bacterioplankton structure and quantify ARGs (tetA, tetB, tetM, ermB, sul1, blaSHV, and ampC) within the bacterioplankton community of the Baltic Sea. Quantitative polymerase chain reaction was applied to quantify ARGs from four different sampling sites of the Baltic Sea over 2 years, and the bacterial communities were profiled sequencing the V6 region of the 16S rRNA gene on Illumina HiSeq2000. The results revealed that all the resistance genes targeted in the study were detectable from the Baltic Sea bacterioplankton. The percentage of tetA, tetB, tetM, ermB, and sul1 genes in the sea bacterial community varied between 0.0077% and 0.1089%, 0.0003% and 0.0019%, 0.0001% and 0.0105%, 0% and 0.0136%, and 0.0001% and 0.0438%, respectively. The most numerous ARG detected was the tetA gene and this gene also had the highest proportion in the whole microbial community. A strong association between bacterioplankton ARGs' abundance data and community phylogenetic composition was found, implying that the abundance of most of the studied ARGs in the Baltic Sea is determined by fluctuations in its bacterial community structure.
Background: Many prokaryotic and eukaryotic microorganisms synthesize a wide range of structurall... more Background: Many prokaryotic and eukaryotic microorganisms synthesize a wide range of structurally different amphiphilic surface active compounds (SACs). SACs find application in almost every industrial sectors. The research on microbial SACs has been confined, mostly, to few well-characterized compounds produced by a small number of microbial genera. Until now, only few studies were concerned with the phylogenetic diversity of SAC-producing bacteria. Furthermore, the majority of the microbial producers described in literature has been isolated from a narrow range of environments, mainly undisturbed and hydrocarbon contaminated soils.
Current Research Topics in Applied Microbiology and Microbial Biotechnology, 2009
Bulletin of Environmental Contamination and Toxicology, 2015
The cessation of mining activities without proper rehabilitation measures has left significant ne... more The cessation of mining activities without proper rehabilitation measures has left significant negative legacy on the surrounding environments. Among the main sources of degradation are abandoned waste dumps and flotation tailings ponds, which are subjected to water erosion and wind dispersion, representing a source of contamination for nearby communities. In semiarid environments the mobilization of the contaminants and the degradation of soils are enhanced owing to the long periods of drought and heat, the seasonal heavy rainfalls and the scarcity of vegetation cover. The traditional disruptive technologies for the remediation of mine tailings are often costly due to the extension of the affected areas. Recently, phytoremediation, based on the use of plants to reduce the concentrations or toxic effects of contaminants in the environment, has been recognized by the scientific community as an environmental friendly technology which is cost-effective for in situ abandoned mine site reclamation. The establishment of a plant cover could indeed promote the development of a diverse microbial community and a better soil structure, which in turns promote plant growth and help to develop a selfsustaining system. In this experimental study, different phytoremediation tests were performed in laboratory under controlled conditions (humidity, temperature, photoperiod). Soils collected at two different Sardinian mine sites were used: Campo Pisano (flotation tailing dam) and Sa Masa (marshy area), both containing zinc (up to 20,000 ppm), lead (up to 5,000 ppm) and cadmium (up to 150 ppm) as the most abundant toxic metals. Tests were performed by applying two selected native plants: Pistacia lentiscus L. and Phragmites australis. Consistently with their respective presence in the selected mine sites, P. lentiscus was studied on both Campo Pisano and Sa Masa soils, whilst P. australis was tested on Sa Masa soil only. The objective of this study was to evaluate: i) the capability of the two species to tolerate high metals concentrations and to extract or immobilize them within the roots; ii) the possibility to mitigate stress on the plants by adding an amendment such as compost. Experiments were conducted by using 1 L reactors, filled with the selected soil and seeded with P. lentiscus or transplanted with P. australis. For each test, ten replicates were used. The results showed that P. australis and P. lentiscus had different adaptation responses and behaved differently in relation to the tested soil and to the addition of compost. When compost was used, the survival and growth of P. australis in Sa Masa soil improved, and a lower uptake of metals in plant tissues was measured. Compost was effective in reducing the metal uptake of P. lentiscus, whilst almost no effect was assessed in relation to the plant survival and growth.
Infection Control and Hospital Epidemiology, Jul 1, 2006
We report the epidemiological investigation of an outbreak ofPseudomonas aeruginosainfection in 6... more We report the epidemiological investigation of an outbreak ofPseudomonas aeruginosainfection in 6 patients who shared, during different periods, the same 2 rooms of a bone marrow transplantation unit. Phenotypic and molecular analysis of isolates from patients and from the environment strongly suggested a single, environmental source of infection.
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Papers by Elena Tamburini