Search results for "BACTERIA"
showing 9 items of 4919 documents
Preliminary results for application of culture-independent molecular methods to olive brines bacterial communities.
2006
Transformation of green table olives requires a brining stage during which olives ferment. In naturally transformed olives, both flavour improvement and debittering are associated to fermentation. Because of brine features, naturally occurring bacteria and yeasts are progressively selected by the high salt concentration, low pH and phenolic compounds with antimicrobial activity. The establishment of an adequate fermenting microflora is essential to obtain a good and safe product; then, during transformation, control of chemical and microbiological parameters is crucial. Currently, microflora is periodically monitored by plate-counting of main groups. These routine analyses, however, don’t s…
Metabolomic Analysis Of Durum Wheat Roots In Response to Arbuscular Mycorrhizal Fungi Inoculation in Field Conditions
2014
Arbuscular mycorrhizal (AM) fungi are commonly occurring fungi that live in an obligate symbiotic status with the majority of land plants. The objective of the present work was to gain insight into the root metabolism changes (primary and secondary metabolism) of durum wheat in response to solely AM fungi inoculation or to combination of AM fungi with plant growth promoting rhizobacteria (PGPR) (Bacillus spp.). Field trial was performed in 2010–2011 in a typical semi-arid Mediterranean area (inner land of Sicily) in absence of fertilization. The untarget metabolomics analysis using the Agilent GC–quadrupole MS identified metabolites playing a key role in symbiosis as well as in root physiol…
Spatial and temporal variation in denitrification and in the denitrifier community in a boreal lake
2011
We investigated the spatial and temporal variation in denitrification rates (isotope-pairing technique, IPT) and in the denitrifier community (examination of gene nirK by denaturing-gradient gel electrophoresis [DGGE] of microbial DNA) in the sediments of a boreal, clear-water, eutrophic lake using samples collected from shallow littoral, deep littoral and shallow profundal sediments during early summer, mid-summer, autumn and winter. The measured denitrification rates (44 to 613 µmol N m−² d−¹) are among the lowest ever reported from lacustrine sediments. Denitrification rates varied both spatially and temporally, being highest in the profundal zone during mid-summer and in the littor…
Does the potentially toxic cyanobacterium Microcystis exist in the soda lakes of East Africa?
2011
Presently, the food chains of the famous saline alkaline flamingo-lakes of East Africa are the focus of intense scientific discussion as the lakes host toxic cyanobacteria, which when consumed by Lesser Flamingos, weaken the birds and therefore make them susceptible to attacks by infective diseases. The distribution, genetic and toxicological aspects of Microcystis in Kenya has been studied extensively. Although there are reports on the occurrence of Microcystis in Kenya’s hypersaline alkaline lakes, they have not been confirmed. Our investigations carried out over a 10-year period in about 50 inland waters showed that Microcystis occurs exclusively in freshwaters, but never in the hypersal…
Potential of an Exploitation of Acid-Tolerant Antimicrobial Microorganisms Evolving Enzyme Systems for the Utilization of Dairy By-products and Ligno…
2016
Assembly and functioning of endophytic bacterial communities in arcto-alpine pioneer plant Oxyria digyna
2019
Plant microbiomes consist of diverse communities of microorganisms, among which bacteria are highly abundant. The microbiomes are crucial for plants as they rely on their microbial associates for many essential functions. The goal of this thesis was to study the functional diversity and assembly rules of endophytic bacterial communities in different plant tissues of the arcto-alpine pioneer plant species, Oxyria digyna. I used high-throughput sequencing and bacterial isolations to characterize the endophytic communities in the leaves and roots of native O. digyna plants (wild plants) and micropropagated aseptic plants (bait plants) in the field. Wild plants and tissue-propagated bait plants…
Effect of single-species and mixed-species leaf leachate on bacterial communities in biofilms
2009
Dissolved organic matter in the form of leaf leachate represents an important carbon and energy source in many lotic ecosystems. In this study, we investigated utilization of mono-specific and mixed-species leaf leachate and impacts on biofilm bacterial community structure. Ceramic tiles were incubated in a Northeast Ohio stream to allow for biofilm development and then exposed in the laboratory to glucose or leachate from: sugar maple (Acer saccharum), pin oak (Quercus palustris), maple oak, American beech (Fagus grandifolia), witch hazel (Hamamelis virginiana), or beech witch hazel. Bacterial responses to these amendments were compared to un-amended controls based on fluorescent in situ h…
Green sulphur bacteria as a component of the photosynthetic plankton community in small dimictic humic lakes with an anoxic hypolimnion
2013
High bacteriochlorophyll (BChl) concentrations in the anoxic water layers of some humic lakes have indicated that green sulphur bacteria (GSB) may be ecologically significant. The abundance and spatial distribution of GSB were therefore addressed in 13 small humic lakes using fragment analysis and sequencing of PCR-amplified 16S rRNA genes. GSB were detected from lakes where the photosynthetically active radiation was at least 1.1 µE m-2 s-1 at the oxic-anoxic boundary layer. In these lakes, 13 to 42% of the 16S rRNA gene sequences of the anoxic water column were assigned to GSB. The spatial distribution of GSB was tightly correlated with the spectrophotometrically measured BChl concentrati…
MLML2R
2019
R package for maximum likelihood estimation of DNA methylation and hydroxymethylation proportions.