Search results for "Bacterial diversity"
showing 10 items of 12 documents
Mapping and determinism of soil microbial community distribution across an agricultural landscape.
2015
Article en open access; International audience; Despite the relevance of landscape, regarding the spatial patterning of microbial communities and the relative influence of environmental parameters versus human activities, few investigations have been conducted at this scale. Here, we used a systematic grid to characterize the distribution of soil microbial communities at 278 sites across a monitored agricultural landscape of 13km(2). Molecular microbial biomass was estimated by soil DNA recovery and bacterial diversity by 16S rRNA gene pyrosequencing. Geostatistics provided the first maps of microbial community at this scale and revealed a heterogeneous but spatially structured distribution…
Distribution patterns of fungi and bacteria in saline soils
2014
Saline soils are environments characterized by uneven temporal and spatial water distribution and localized high concentrations of salts. Spatial distribution patterns of fungi and bacteria in saline soils, and the link between microbial community dynamics and salts accumulation are critical issues throughout the world (Ettema, Wardle 2002). This study was focused on spatial distribution patterns of soil fungi and bacteria in a saline soil located in Piana del Signore (Gela, Italy) where some ecological variables acted as shaping factors in aboveground and belowground communities distribution. Bacterial, archaeal, and fungal communities diversity and distribution in ten soil sites (A horizo…
Exploring diversity and biotechnological potential of lactic acid bacteria from tocosh - traditional Peruvian fermented potatoes - by high throughput…
2018
Lactic acid bacteria (LAB) diversity associated with tocosh, Peruvian traditional fermented potatoes, was for the first time investigated by culturing and high throughput sequencing (HTS) approaches. They were applied on three samples i.e. freshly harvested potatoes, one-month and eight-months production. While by culture-dependent approach a few Lactobacillus (Lb) species (Lb. sakei, Lb. casei, Lb. farciminis, Lb. brevis, Lb. fermentum) and Leuconostoc (Ln) mesenteroides were identified, twenty-four OTUs belonging to six LAB genera were considered in tocosh samples by HTS, being Lactobacillus dominant in all three samples. LAB predominated on fresh potatoes, while Clostridium, Zymophilus a…
Response of soil bacterial communities to the incorporation of crop residues : influence of agricultural practices and link with the soil biological …
2010
The effect of the location of wheat residues (soil surface vs. incorporated in soil) on their decomposition and on soil bacterial communities was investigated by the means of a field experiment. Bacterial-Automated Ribosomal Intergenic Spacer Analysis (B-ARISA) of DNA extracts from residues, detritusphere (soil adjacent to residues), and bulk soil evidenced that residues constitute the zone of maximal changes in bacterial composition. However, the location of the residues influenced greatly their decomposition and the dynamics of the colonizing bacterial communities. Sequencing of 16S rRNA gene in DNA extracts from the residues at the early, middle, and late stages of degradation confirmed …
Bacterial Diversity in a Dynamic and Extreme Sub-Arctic Watercourse (Pasvik River, Norwegian Arctic)
2020
Microbial communities promptly respond to the environmental perturbations, especially in the Arctic and sub-Arctic systems that are highly impacted by climate change, and fluctuations in the diversity level of microbial assemblages could give insights on their expected response. 16S rRNA gene amplicon sequencing was applied to describe the bacterial community composition in water and sediment through the sub-Arctic Pasvik River. Our results showed that river water and sediment harbored distinct communities in terms of diversity and composition at genus level. The distribution of the bacterial communities was mainly affected by both salinity and temperature in sediment samples, and by oxygen…
Lifestyle-Induced Microbial Gradients: An Indian Perspective
2019
Introduction: Urbanization is a globally pervasive trend. Although urban settings provide better access to infrastructure and opportunities, urban lifestyles have certain negative consequences on human health. A number of recent studies have found interesting associations between the structure of human gut microbiota and the prevalence of metabolic conditions characterizing urban populations. The present study attempts to expand the footprint of these investigations to an Indian context. The objectives include elucidating specific patterns and gradients based on resident habitat and lifestyles (i.e., tribal and urban) that characterize gut microbial communities. Methods: Available 16S rRNA …
Methanotrophic activity and diversity of methanotrophs in volcanic geothermal soils at Pantelleria (Italy)
2014
Volcanic and geothermal systems emit endogenous gases by widespread degassing from soils, including CH4, a greenhouse gas twenty-five times as potent as CO2. Recently, it has been demonstrated that volcanic or geothermal soils are not only a source of methane, but are also sites of methanotrophic activity. Methanotrophs are able to consume 10–40 Tg of CH4 a−1 and to trap more than 50% of the methane degassing through the soils. We report on methane microbial oxidation in the geothermally most active site of Pantelleria (Italy), Favara Grande, whose total methane emission was previously estimated at about 2.5 Mg a−1 (t a−1). Laboratory incubation experiments with three top-soil samples from …
Key features of bacterial communities in Southern Europe soils vulnerable to desertification
2019
Mediterranean soils are experiencing increasingly negative effects of climate change due to drought and extreme weather phenomena that negatively affect agriculture, already suffering social and economic constraints. The LIFE project DESERT-ADAPT - Preparing desertification areas for increased climate change - (http://www.desert-adapt.it/index.php/en/) focuses on agricultural adaptation measures aimed at reverting ongoing desertification trends, while improving the socioeconomic conditions of farmers. The soil microbiota is recognized as key player in both diversity and productivity of terrestrial ecosystems and it is mandatory to include its role in sustainable agronomic management. In ord…
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 (isotopepairing technique, IPT) and in the denitrifier community (examination of gene nirK by denaturinggradient 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. Denitri fi - cation rates varied both spatially and temporally, being highest in the profundal zone during midsummer and in the littoral z…
Response of soil bacterial communities to the incorporation of crop residues : influence of agricultural practices and link with the soil biological …
2010
The effect of the location of wheat residues (soil surface vs. incorporated in soil) on their decomposition and on soil bacterial communities was investigated by the means of a field experiment. Bacterial-Automated Ribosomal Intergenic Spacer Analysis (B-ARISA) of DNA extracts from residues, detritusphere (soil adjacent to residues), and bulk soil evidenced that residues constitute the zone of maximal changes in bacterial composition. However, the location of the residues influenced greatly their decomposition and the dynamics of the colonizing bacterial communities. Sequencing of 16S rRNA gene in DNA extracts from the residues at the early, middle, and late stages of degradation confirmed …