Search results for "biologia generale"
showing 10 items of 319 documents
Biodegradazione di miscele di gasolio in suoli contaminati
2008
Il biorisanamento mediante l’utilizzo di microrganismi ha un ruolo fondamentale nelle pratiche di trasformazione di molecole potenzialmente tossiche quali gli idrocarburi, che quotidianamente vengono riversati negli ecosistemi provocando fenomeni di antropizzazione in equilibri naturali particolarmente sensibili. Numerosi ceppi batterici sono abili degradatori e mineralizzatori di sostanze inquinanti xenobiotiche di sintesi e recalcitranti non esistenti in natura, quali i derivati di idrocarburi aromatici e policlorobifenili (PCB). Mediante colture su mezzo minerale Bushnell-Haas agarizzato (BH) in presenza di una miscela di idrocarburi come unica fonte di carbonio sono stati isolati 5 cepp…
Degradazione di pesticidi organofosforici in matrici ambientali
2008
Matrici quali acqua, suolo ed aria sono costantemente soggette a forti pressioni antropiche. I pesticidi pur avendo apportato grandi benefici alle attività agricole influiscono negativamente sugli equilibri degli ecosistemi. Circa 85-90% dei principi attivi applicati in agricoltura non raggiunge gli organismi a cui sono destinati, ma viene disperso nell’ambiente. In tale contesto l’individuazione di microrganismi deputati alla loro degradazione diventa un importante mezzo per la salvaguardia ambientale e della salute umana. Lo scopo del presente lavoro è stato quello di isolare batteri del suolo capaci di degradare composti organofosforici, i quali rivestono una notevole importanza nelle pr…
Biodiversity of organophosphorus-degrading bacteria isolated from agricultural soils
2009
Organophosphorus (OP) insecticides are used all over the world for crop protection. Although OPs are less persistent than organochlorine pesticides, they still constitute an environmental risk thus increasing the social concern about their levels in soils, surface and ground waters. Biodegradation by microorganisms is primarily responsible for elimination of the OP insecticides released to the environment. In the present study the OP degrading potential of agricultural soils with different agronomic history was investigated. Using enrichment cultures, with parathion or dimethoate as the sole C and energy sources, 47 bacterial isolates were obtained from OPs contaminated and pristine agricul…
Paracentrin 1, a synthetic antimicrobial peptide fragment of a beta-thymosin from the sea-urchin Paracentrotus lividus, interferes with staphylococca…
2014
Processing of metals and metalloids by actinobacteria: Cell resistance mechanisms and synthesis of metal(loid)-based nanostructures
2020
Metal(loid)s have a dual biological role as micronutrients and stress agents. A few geochemical and natural processes can cause their release in the environment, although most metal-contaminated sites derive from anthropogenic activities. Actinobacteria include high GC bacteria that inhabit a wide range of terrestrial and aquatic ecological niches, where they play essential roles in recycling or transforming organic and inorganic substances. The metal(loid) tolerance and/or resistance of several members of this phylum rely on mechanisms such as biosorption and extracellular sequestration by siderophores and extracellular polymeric substances (EPS), bioaccumulation, biotransformation, and me…
Spoilage of oat bran by sporogenic microorganisms revived from soil buried 4000 years ago in Iranian archaeological site
2015
Abstract The Bronze Age archaeological site of Shahr-i Sokhta (30° 39′ N; 61° 24’ E), located today in southeastern Iran, Sistan region, is a special archaeological deposit in which the exceptional preservation of human, plant and animal remains, due to the dry climate of the region, can provide detailed information on one of the first complex proto-urban societies. In recent years, there has been growing interest in changes in local climate and environment as major reasons why the settlement was abandoned about 4000 years ago. Food shortage has been regarded as a direct effect of these changes. No attention has been paid to the potential health hazards associated with ancient urban/domesti…
Targeting the Sortase A Transpeptidase to Tackle Gram-positive Pathogens
2013
The virulence factors include the cell-wall associated proteins called MSCRAMMs (microbial surface components recognizing adhesive matrix molecules) that can promote the adhesion to host proteins, for example, the fibronectin that is very common in host tissues. The cellwall associated proteins are necessary for host colonization, invasion, immune evasion and biofilm formation [4]. The biofilms, multistratified bacterial communities that grow on a biological or artificial surface, are responsible for chronic infectious diseases and for device or biomaterial associated infections, and are more resistant to host immune defence system and to conventional antibiotics [5].
Cloning of an alkane hydroxylase system in a long chain n-alkane- degrader Gordonia sp.
2008
Five Gram-positive GC rich n-alkane degraders were isolated from a long-term accidentally contaminated beach in Sicily and identified as one Nocardia, two Rhodococcus and two Gordonia strains (Quatrini et al., 2008 J. Appl. Microbiol. 104:251-9). All the isolates were able to grow on long and very long chain n-alkanes up to C36. Diverging alkane-hydroxylase encoding genes (alkB) were detected by PCR using degenerated primers in all the strains. Multiple sequences were obtained from the Nocardia strain while only one alkB gene was detected in Rhodococcus and Gordonia. The aim of this work is to genetically characterize the alk cluster in one of the two Gordonia strains called SoCg. Pulsed Fi…