Search results for "biologia generale"

Anti-adhesion agents against Gram-positive pathogens

2014

The rise of antibiotic-resistance as well as the deficiency of investments by pharmaceutical companies in the development of new antibiotics, have stimulated the investigation of alternative strategies to conventional antibiotics for counteracting the pathogens. A fundamental step of Gram positive pathogenesis is the bacterial adhesion to the host tissue involving a direct and a specific interaction between bacterial surface molecules and host ligands. Targeting the adhesion is a good strategy to design novel anti-infective drugs agents useful to interfere with the pathogenic process and with a virulence mechanism as biofilm formation. This review is focused on anti-virulence compounds whic…

Untargeted Metabolomics Investigation on Selenite Reduction to Elemental Selenium by Bacillus mycoides SeITE01

2021

Bacillus mycoides SeITE01 is an environmental isolate that transforms the oxyanion selenite (SeO32−) into the less bioavailable elemental selenium (Se0) forming biogenic selenium nanoparticles (Bio-SeNPs). In the present study, the reduction of sodium selenite (Na2SeO3) by SeITE01 strain and the effect of SeO32− exposure on the bacterial cells was examined through untargeted metabolomics. A time-course approach was used to monitor both cell pellet and cell free spent medium (referred as intracellular and extracellular, respectively) metabolites in SeITE01 cells treated or not with SeO32−. The results show substantial biochemical changes in SeITE01 cells when exposed to SeO32−. The initial u…

The gut microbiota of larvae of Rhynchophorus ferrugineus Oliver (Coleoptera: Curculionidae)

2014

Background: The red palm weevil (RPW) Rhynchophorus ferrugineus Olivier (Coleoptera: Curculionidae) is one of the major pests of palms. The larvae bore into the palm trunk and feed on the palm tender tissues and sap, leading the host tree to death. The gut microbiota of insects plays a remarkable role in the host life and understanding the relationship dynamics between insects and their microbiota may improve the biological control of insect pests. The purpose of this study was to analyse the diversity of the gut microbiota of field-caught RPW larvae sampled in Sicily (Italy). Results: The 16S rRNA gene-based Temporal Thermal Gradient Gel Electrophoresis (TTGE) of the gut microbiota of RPW …

Novel Sources of Biodiversity and Biomolecules from Bacteria Isolated from a High Middle Ages Soil Sample in Palermo (Sicily, Italy)

2023

: The urban plan of Palermo (Sicily, Italy) has evolved throughout Punic, Roman, Byzantine, Arab, and Norman ages until it stabilized within the borders that correspond to the current historic center. During the 2012 to 2013 excavation campaign, new remains of the Arab settlement, directly implanted above the structures of the Roman age, were found. The materials investigated in this study derived from the so-called Survey No 3, which consists of a rock cavity of subcylindrical shape covered with calcarenite blocks: it was probably used to dispose of garbage during the Arabic age and its content, derived from daily activities, included grape seeds, scales and bones of fish, small animal bon…

Methylacidimicrobium thermophilum AP8, a Novel Methane- and Hydrogen-Oxidizing Bacterium Isolated From Volcanic Soil on Pantelleria Island, Italy

2021

The Favara Grande is a geothermal area located on Pantelleria Island, Italy. The area is characterized high temperatures in the top layer of the soil (60°C), low pH (3–5) and hydrothermal gas emissions mainly composed of carbon dioxide (CO2), methane (CH4), and hydrogen (H2). These geothermal features may provide a suitable niche for the growth of chemolithotrophic thermoacidophiles, including the lanthanide-dependent methanotrophs of the phylum Verrucomicrobia. In this study, we started enrichment cultures inoculated with soil of the Favara Grande at 50 and 60°C with CH4 as energy source and medium containing sufficient lanthanides at pH 3 and 5. From these cultures, a verrucomicrobial met…

The Streptomyces coelicolor Small ORF trpM Stimulates Growth and Morphological Development and Exerts Opposite Effects on Actinorhodin and Calcium-De…

2020

In actinomycetes, antibiotic production is often associated with a morpho-physiological differentiation program that is regulated by complex molecular and metabolic networks. Many aspects of these regulatory circuits have been already elucidated and many others still deserve further investigations. In this regard, the possible role of many small open reading frames (smORFs) in actinomycete morpho-physiological differentiation is still elusive. In Streptomyces coelicolor, inactivation of the smORF trpM (SCO2038) – whose product modulates L-tryptophan biosynthesis – impairs production of antibiotics and morphological differentiation. Indeed, it was demonstrated that TrpM is able to interact w…

Endophytic Bacteria and Essential Oil from Origanum vulgare ssp. vulgare Share Some VOCs with an Antibacterial Activity

2022

Medicinal aromatic plants’ essential oils (EOs) are mixtures of volatile compounds showing antimicrobial activity, which could be exploited to face the emerging problem of multi-drug resistance. Their chemical composition can depend on the interactions between the plant and its endophytic microbiota, which is known to synthesize volatile organic compounds (VOCs). However, it is still not clear whether those volatile metabolites can contribute to the composition of the aroma profile of plants’ EOs. The aims of this study were to characterize medicinal plant O. vulgare ssp. vulgare bacterial endophyte VOCs, evaluating their ability to antagonize the growth of opportunistic human pathogens bel…

Endophytic Bacteria Associated with Origanum heracleoticum L. (Lamiaceae) Seeds

2022

Seed-associated microbiota are believed to play a crucial role in seed germination, seedling establishment, and plant growth and fitness stimulation, due to the vertical transmission of a core microbiota from seeds to the next generations. It might be hypothesized that medicinal and aromatic plants could use the seeds as vectors to vertically transfer beneficial endophytes, providing plants with metabolic pathways that could influence phytochemicals production. Here, we investigated the localization, the structure and the composition of the bacterial endophytic population that resides in Origanum heracleoticum L. seeds. Endocellular bacteria, surrounded by a wall, were localized close to th…

Metabolic pathways in Microbispora sp. ATCC-PTA 5024, producer of NAI-107 lantibiotic

2014

Metabolic pathways and regulatory networks associated to NAI-107 lantibiotic production in Microbispora sp. ATCC-PTA-5024

2015

The filamentous actinobacterium Microbispora sp. ATCC-PTA-5024 produces the lantibiotic NAI-107, which is effective against multidrugresistant Gram-positive pathogens. In actinomycetes, the biosynthesis of antibiotics is elicited as a physiological response that is controlled by a complex regulatory network involving general and pathwayspecific regulators. The ‘omics technologies can be useful to explore molecular physiology in bacterial cells and elucidate molecular and metabolic events associated to antibiotic production in order to develop robust and economically-feasible production processes. To this aim, differential proteomic analyses, based two-dimensional difference in gel electroph…