Search results for "Micro"
showing 10 items of 23412 documents
Biogenic Fenton process - A possible mechanism for the mineralization of organic carbon in fresh waters.
2020
To explore the mechanisms that mineralize poorly bioavailable natural organic carbon (OC), we measured the mineralization of OC in two lake waters over long-term experiments (up to 623 days) at different pH and iron (Fe) levels. Both the microbial and photochemical mineralization of OC was higher at pH acidified to 4 than at the ambient pH 5 or an elevated pH 6. During 244 days, microbes mineralized up to 60% of OC in the 10-mu m filtrates of lake water and more than 27% in the 1-mu m filtrates indicating that large-sized microbes/grazers enhance the mineralization of OC. A reactivity continuum model indicated that the acidification stimulated the microbial mineralization of OC especially i…
Apoptotic-like Leishmania exploit the host´s autophagy machinery to reduce T-cell-mediated parasite elimination
2015
Apoptosis is a well-defined cellular process in which a cell dies, characterized by cell shrinkage and DNA fragmentation. In parasites like Leishmania, the process of apoptosis-like cell death has been described. Moreover upon infection, the apoptotic-like population is essential for disease development, in part by silencing host phagocytes. Nevertheless, the exact mechanism of how apoptosis in unicellular organisms may support infectivity remains unclear. Therefore we investigated the fate of apoptotic-like Leishmania parasites in human host macrophages. Our data showed--in contrast to viable parasites--that apoptotic-like parasites enter an LC3(+), autophagy-like compartment. The compartm…
Assessment of microplastics and other contaminants in marine vertebrates from the Western Mediterranean Sea
2023
Mediterranean marine biodiversity is under threat by pollution. For this reason, the main objective of this thesis was to analyse the presence of pollutants of concern in Mediterranean marine species. These studies are located in the Valencian Community (Spain), where we find loggerhead turtles, striped dolphins, and jewel lanternfish. Hence, we: 1. Analysed pesticides, heavy metals and phthalates in tissues of loggerhead turtles. 2. Studied microdebris present in beaches that are sporadically used as nesting grounds by loggerhead turtles. 3. Analysed striped dolphins# exposure to microplastics. 4. Quantified jewel lanternfish exposure to microplastics and tested their role as bioindicators…
Gordonia sp. SoCg alkB gene confers the ability to degrade and use n-alkanes as carbon source in Gram positive bacteria
2010
Gordonia sp. SoCg, a Gram positive strain able to grow on long chain n-alkanes1, possess a single copy of alkB2 gene, whose product is required for n-alkane hydroxylation3. An analysis of alkB flanking regions revealed five ORFs which were designed as orf1, rubA3, rubA4, rubB and alkU, according to the sequence 14 homology with that of known alk clusters3. In G. sp. SoCg the transcription of these genes was induced by long-chain and solid n-alkanes as revealed by quantitative RT-PCR, and the essential role of alkB in nalkane degradation was demonstrated by the construction of an alkB disruption mutant strain3. The SoCg alkB gene was successfully expressed in Streptomyces coelicolor M145 (M1…
Response of microbial biomass and carbon dynamics to changing hydrological conditions in old peat deposits
2018
Peatlands play key roles in the global ecosystem carbon (C) balance, as important C-stores. Their efficiency as long-term C-stores or atmospheric C sink is affected by the rate of microbial mineralization. Most studies on the climate change effects on the microbial communities and C-cycling in peatlands have focused on the surface layers. This thesis compared microbial biomass, community composition and internal C cycling processes in drained vs. natural peat profiles with focus on deep old peat. Using the phospholipid fatty acid (PLFA) and rRNA gene analyses, the study particularly looked at the impact of long-term drainage and the short-term effects of temperature and water content on the…
Caracterización de los componentes genéticos y ambientales implicados en el envejecimiento de las levaduras vínicas
2012
La mayor parte de la fermentación vínica discurre cuando las células de la levadura Saccharomyces cerevisiae han dejado de dividirse. Así pues, la viabilidad en fase estacionaria, llamada longevidad cronológica (LC), es esencial para que la vinificación se lleve a buen término. En este trabajo de tesis doctoral, se han caracterizado diversos componentes ambientales y genéticos que influyen en la longevidad cronológica de las levaduras vínicas. En cuanto a los componentes ambientales, el incremento de la acidez y la temperatura del medio promueven el envejecimiento. Los polifenoles resveratrol y quercetina y los compuestos de dos carbonos que se producen durante la fermentación, afectan de m…
Procarioti dalle mille risorse: nuove scoperte sui metabolismi batterici che utilizzano la luce
2013
I batteri fototrofi costituiscono un ampio ed eterogeneo gruppo di procarioti ampiamente distribuiti nel plancton marino ed i loro processi basati sulla luce sostengono e controllano il flusso di energia negli oceani. Recenti scoperte di nuovi batteri includono almeno tre modalità di fotosintesi: la fotosintesi aerobica ossigenica (tipica dei cianobatteri e simile a quella condotta dalle piante), la fotosintesi anaerobica anossigenica e la fotosintesi aerobica anossigenica (entrambe esclusive dei procarioti). Altri importanti processi basati sulla luce utilizzano le rodopsine, contribuendo così al metabolismo energetico cellulare. La fotosintesi ossigenica “pura” sembra più l’eccezione che …
LIQUID BIOPSY AS A DYNAMIC TOOL FOR LUNG CANCER MANAGEMENT: A FEASIBILITY STUDY FOR PLASMA-DERIVED EXOSOMAL miRNAs AND CELL-FREE DNA.
When the Grafting of Double Decker Phthalocyanines on Si(100)-2 × 1 Partly Affects the Molecular Electronic Structure
2016
International audience; A combined X-ray photoelectron spectroscopy (XPS), scanning tunneling microscopy (STM), and density functional theory (DFT) study has been performed to characterize the adsorbate interaction of lutetium biphthalocyanine (LuPc2) molecules on the Si(100)-2 × 1 surface. Large molecule–substrate adsorption energies are computed and are found to compete with the molecule–molecule interactions of the double decker molecules. A particularly good matching between STM images and computed ones confirms the deformation of the molecule upon the absorption process. The comparison between DFT calculations and XP spectra reveals that the electronic distribution in the two plateaus …