Search results for "biologia generale"
showing 10 items of 319 documents
So close, so different: geothermal flux shapes divergent soil microbial communities at neighbouring sites
2016
This study is focused on the (micro)biogeochemical features of two close geothermal sites (FAV1 and FAV2), both selected at the main exhalative area of Pantelleria Island, Italy. A previous biogeochemical survey revealed high CH4 consumption and the presence of a diverse community of methanotrophs at FAV2 site, whereas the close site FAV1 was apparently devoid of methanotrophs and recorded no CH4 consumption. Next-Generation Sequencing (NGS) techniques were applied to describe the bacterial and archaeal communities which have been linked to the physicochemical conditions and the geothermal sources of energy available at the two sites. Both sites are dominated by Bacteria and host a negligib…
Chemo-enzymatic Conversion of Glucose in 5-Hydroxymethylfurfural: The Joint Effect of Ionic Liquids and Ultrasound
2020
For the valorization of lignocellulosic biomass, a key step is unlocking the conversion of glucose to suitable chemical platforms. To this aim, we herein describe the sequential chemo-enzymatic conversion of glucose into 5-hydroxymethylfurfural (5-HMF), in two steps: glucose isomerization to fructose, catalyzed by glucose isomerase (GI) and fructose dehydration to 5-HMF promoted by Amberlyst 15. The novelty of our approach lies in the use of crude cell extracts of Streptomyces coelicolor showing GI activity, as isomerization catalysts, along with a commercial immobilized GI. Under optimized reaction conditions, we obtained a conversion to 5-HMF (C5‑HMF) from glucose of 50% in the H2O/[bmim]…
Food Processing and Foodborne Illness
2015
Food processing means manipulation of raw materials from plants or animals into food. Since agriculture and animal husbandry were established postharvest procedures were necessary to preserve for a longer time the increasing food supplies coming from the fields and domesticated animals. Food is one of the best culture medium for a lot of microorganisms and preventing food spoilage caused by enzymes and microorganisms is crucial. Deterioration of food is caused mainly by three natural processes: 1. Oxidation – vegetables after harvesting or meat after animal slaughtering get in contact with the oxygen in the air that makes them rancid and unpleasant. 2. Enzyme action – all food contains natu…
Metagenomic analysis of the microbiota hindgut of Reticulitermes lucifugus (Rossi) (Isoptera: Rhinotermitidae)
2008
Termites hindguts host a microbial community consisting of anaerobic flagellates and bacteria. This gut microflora is responsible for the degradation of lignocellulosic material. Here we report the data concerning the analysis of the hindgut microbial community of Reticulitermes lucifugus (Rossi), a termite commonly present in Italy, based on a metagenomic approach. Metagenomic DNA was extracted from the gut content of termites and the SSU rDNA was polymerase chain reaction (PCR) - amplified using universal primers for prokaryotes and eukaryotes. Two clone libraries were constructed and clones were grouped into Operational Taxonomic Units (OTU) by RFLP analysis. One representative clone was…
Isolation, identification and metabolic characterization of hydrocarbonoclastic bacteria from a polluted harbour in Sicily (Italy)
2014
The petrochemical site of Priolo-Augusta-Melilli (Sicily, Italy), is a Site of National Interest (SIN) due to high levels of environmental contamination of the coastline and a specific "national program of environmental remediation and restoration" was developed in order to allow remediation and restoration of contaminated sites. In order to identify the key hydrocarbon degraders and explore the natural bioremediation potential of the contaminated area, a total of six sediment and sea water cores were collected inside the Priolo Harbour (SR, Italy). After biological (bacterial counts, PCR-DGGE) and chemical-physical characterization (quali-, quantitative measures of hydrocarbons and heavy m…
Phytochemical-rich extracts of Helianthemum lippii possess antimicrobial, anticancer, and anti-biofilm activities
2022
Helianthemum lippii is a perennial shrubby plant growing in the sandy environments of Italy, Mediterranean countries of North Africa and Middle East. H. lippii is used in traditional medicine but there are very few reports referring to the phytochemical characterization, the ethnopharmacology, and the biological activity of H. lippii. The goal of this study was todetermine the phytochemical composition of different H. lippii extracts, cold (CME) and hot (HME) methanol, cold (CPEE) and hot (HPEE) petroleum ether, as well as to evaluate their anticancer and antimicrobial activities and biofilm formation reduction. Fifty-fours phytocompounds have been determined by HPLC-UV-ESI-QTOF-MS analysis…
MAP OF 3D DISTRIBUTION OF HYDROCARBONOCLASTIC BACTERIA IN MEDITERRANEAN SEA
2013
The obligate hydrocarbonoclastic bacteria (OHCB) have been recognized and shown to play a significant role in the biological removal of hydrocarbons from polluted marine waters. The introduction of oil or hydrocarbons into seawater leads to successive blooms of a relatively limited number of indigenous marine bacterial genera (Alcanivorax, Marinobacter, Thallassolituus, Cycloclasticus and Oleispira) which are present at low or undetectable levels before the polluting event. The types of OHCB that bloom depend directly from level and type of pollution and from parameters as the latitude/temperature, salinity, redox etc.... In this work, using data present in GeneBank we have create a virtual…
Biodegradation Potential of Oil-degrading Bacteria Related to the Genus Thalassospira Isolated from Polluted Coastal Area in Mediterranean Sea
2021
Three bacterial species related to the genus Thalassospira (T. lucentensis, T. xianhensis and T. profundimaris), isolated from polluted sediment and seawater samples collected from Priolo Bay (eastern coast of Sicily, Ionian Sea), were analyzed for their biotechnological potential. For this purpose, the presence of specific catabolic genes associated to aliphatic and aromatic hydrocarbon metabolism, the production of biosurfactants and emulsification activity, the capability to degrade oil-derived linear, branched, cyclic alkanes, and polycyclic aromatic hydrocarbons (PAHs) were evaluated. Alkane hydroxylase gene (alkano-monoxygenase alkb and citocrome P450) were present in genome of all st…
Artificial Chromosomes to Explore and to Exploit Biosynthetic Capabilities of Actinomycetes
2012
Actinomycetes are an important source of biologically active compounds, like antibiotics, antitumor agents, and immunosuppressors. Genome sequencing is revealing that this class of microorganisms has larger genomes relative to other bacteria and uses a considerable fraction of its coding capacity (5–10%) for the production of mostly cryptic secondary metabolites. To access actinomycetes biosynthetic capabilities or to improve the pharmacokinetic properties and production yields of these chemically complex compounds, genetic manipulation of the producer strains can be performed. Heterologous expression in amenable hosts can be useful to exploit and to explore the genetic potential of actinom…
Synthesis and Antileukemic Activity of New 3-(5-Methylisoxazol-3-yl) and 3-(Pyrimidin-2-yl)-2-styrylquinazolin-4(3H)-ones.
2003
3-(3-Methylisoxazol-5-yl) and 3-(pyrimidin-2-yl)-2-styrylquinazolin-4(3H)-ones 8a–l and 9a,c–e,h–l were synthesized by refluxing in acetic acid the corresponding 2-methylquinazolinones 6 and 8 with the opportune benzoic aldehyde for 12 h. The synthesized styrylquinazolinones 8a–l and 9a,c–e,h–l were tested in vitro for their antileukemic activity against L-1210 (murine leukemia), K-562 (human chronic myelogenous leukemia) and HL-60 (human leukemia) cell lines showing in some cases good activity.