Search results for "Microorganisms."
showing 10 items of 70 documents
Restoration practices in Mediterranean habitats using native woody species
2017
Since the beginning of the XXI century, Legambiente (a national environmental association), supported by the University of Palermo, has launched several naturalization projects within three Sicilian nature reserves: 1)Isola di Lampedusa (Agrigento Province); 2)Macalube di Aragona (Agrigento Province); 3)Lago Sfondato (Caltanissetta Province). Interventions were carried out on bare lands and degraded sites where natural vegetation cover was almost completely disappeared. The main aim was to restore native habitats following the principles of ecological restoration. Accordingly, differently from the classical approach, consisting in the use of preparatory species, usually Pines, native shrubs…
Experimental Evaluation of a New Thermal Process for Microorganisms Inactivation
2015
A new thermal process for the inactivation of microorganisms in beverages has been studied and is presented in this paper. The treatment, not yet studied in the scientific literature, mainly consists of a thermal shock characterized by temperature increases up to 30°C/s, with final temperatures up to 65°C. This study presents the first experimental results obtained by the application of the new thermal treatment, with different combinations of the process parameters (rate of temperature rise, final temperature and holding time), on separate suspensions of Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, Listeria innocua and Candida albicans. The required rapid temperature in…
Advanced Strategies for Food-Grade Protein Production: A New E. coli/Lactic Acid Bacteria Shuttle Vector for Improved Cloning and Food-Grade Expressi…
2019
Food-grade production of recombinant proteins in Gram-positive bacteria, especially in LAB (i.e., Lactococcus, Lactobacillus, and Streptococcus), is of great interest in the areas of recombinant enzyme production, industrial food fermentation, gene and metabolic engineering, as well as antigen delivery for oral vaccination. Food-grade expression relies on hosts generally considered as safe organisms and on clone selection not dependent on antibiotic markers, which limit the overall DNA manipulation workflow, as it can be carried out only in the expression host and not in E. coli. Moreover, many commercial expression vectors lack useful elements for protein purification. We constructed a &ld…
Multidrug and broad-spectrum cephalosporin resistance among Salmonella enterica serotype enteritidis clinical isolates in southern Italy.
2002
ABSTRACT From 1992 to 1997, only six sporadic isolates of Salmonella enterica serotype Enteritidis from patients with cases of gastroenteritis in southern Italy exhibited resistance to broad-spectrum cephalosporins. Five isolates produced SHV-12, and one isolate encoded a class C β-lactamase. The bla SHV-12 gene was located in at least two different self-transferable plasmids, one of which also carried a novel class 1 integron.
Human Monkeypox: A Comprehensive Narrative Review and Analysis of the Public Health Implications.
2022
Recently, numerous cases of monkeypox were reported from several non-endemic countries in Europe, North America, and Oceania, suggesting an unusual and alarming public health issue, particularly considering that the disease is not directly related to human or animal travels. Attention is currently being drawn to this phenomenon since more than 70% of the global population is no longer vaccinated against smallpox. Indeed, the smallpox vaccination also confers some indirect degree of protection against other poxviruses, including monkeypox. We performed a narrative review to describe the existing literature with regard to monkeypox using the MEDLINE, EMBASE, and Scopus databases. This review …
Documento de consenso sobre el tratamiento antimicrobiano de las infecciones bacterianas odontogénicas
2005
Las infecciones de la cavidad bucal son un problema de salud pública frecuente y motivo constante de prescripción antibiótica; el 10% de los antibióticos se emplean para tratar este problema. Sin embargo, hasta la fecha son pocos los estudios realizados para determinar su incidencia. Asímismo, su relación con ciertas enfermedades sistémicas (cardiacas, endocrinas, etc...) confiere a estas patologías una importancia vital. A pesar de la reconocida frecuencia e importancia de las infecciones odontogénicas, llama la atención la actual dispersión de criterio en varios aspectos referentes a su clasificación, terminología y recomendaciones terapéuticas. El objetivo principal de este documento, re…
Electrical Pumping of Potassium Ions Against an External Concentration Gradient in a Biological Ion Channel
2013
We show experimentally and theoretically that significant currents can be obtained with a biological ion channel, the OmpF porin of Escherichia coli, using zero-average potentials as driving forces. The channel rectifying properties can be used to pump potassium ions against an external concentration gradient under asymmetric pH conditions. The results are discussed in terms of the ionic selectivity and rectification ratio of the channel. The physical concepts involved may be applied to separation processes with synthetic nanopores and to bioelectrical phenomena. (C) 2013 AIP Publishing LLC.
Structure of Rhodococcus erythropolis limonene-1,2-epoxide hydrolase reveals a novel active site
2003
Epoxide hydrolases are essential for the processing of epoxide-containing compounds in detoxification or metabolism. The classic epoxide hydrolases have an alpha/beta hydrolase fold and act via a two-step reaction mechanism including an enzyme-substrate intermediate. We report here the structure of the limonene-1,2-epoxide hydrolase from Rhodococcus erythropolis, solved using single-wavelength anomalous dispersion from a selenomethionine-substituted protein and refined at 1.2 A resolution. This enzyme represents a completely different structure and a novel one-step mechanism. The fold features a highly curved six-stranded mixed beta-sheet, with four alpha-helices packed onto it to create a …
Simple molecular model for the binding of antibiotic molecules to bacterial ion channels
2003
A molecular model aimed at explaining recent experimental data by Nestorovich et al. [Proc. Natl. Acad. Sci. USA 99, 9789 (2002)] on the interaction of ampicillin molecules with the constriction zone in a channel of the general bacterial porin, OmpF (outer membrane protein F), is presented. The model extends T. L. Hill’s theory for intermolecular interactions in a pair of binding sites [J. Am. Chem. Soc. 78, 3330 (1956)] by incorporating two binding ions and two pairs of interacting sites. The results provide new physical insights on the role of the complementary pattern of the charge distributions in the ampicillin molecule and the narrowest part of the channel pore. Charge matching of int…
Pisum sativum – Pseudomonas interactions : influence on iron nutrution, growth and immunity of the host plant
2020
The project aimed at making progress in the knowledge of the iron-mediated interactions between pea and fluorescent pseudomonads in order to promote the iron-nutrition and health of the host-plant. A bibliographical study was conducted to draw up the state of the art concerning the influence of rhizosphere microorganisms on plant iron status (Chapter 1).Pisum sativum has been chosen as an agronomic model-plant because of its high potential in agroecology and in Human nutrition related to its ability to fix atmospheric nitrogen and to the high amino-acids content of its seeds. However, this species suffers from a high susceptibility to iron deficiency as expressed by the well-known chlorosis…