Role of horizontal gene transfer and cooperation in rhizosphere microbiome assembly.

Microbes employ a variety of mechanisms, encompassing chemical signaling (e.g., quorum-sensing molecules) and genetic processes like horizontal gene transfer (HGT), to engage in interactions.

sp. Strain Metal(loid) and Antibiotic Resistance Isolated from Estuarine Soil Contaminated Mine Tailing from the Fundão Dam.

In 2015 a mine dam with Mn-Fe-rich tailings collapsed releasing million tons of sediments over an estuary, in the Southwest of Brazil. The tailings have a high concentration of metals that contaminated soil until the present day. The high contaminant concentrations possibly caused a selection for microorganisms able to strive in such harsh conditions.

Complete Genome Sequence of a sp. Strain Isolated from Estuarine Soil Contaminated with Mine Tailings from the Samarco Disaster at Fundão Dam.

We report the complete genome sequence of strain 21P, which was isolated from estuarine soil contaminated with mine tailings from the Samarco disaster, which occurred in 2015 in Brazil. The genome sequence comprised 4,739,655 bp, with a G+C content of 43.2%, and harbors multiple antibiotic and metal resistance genes.

Complete Genome Sequence of Bacillus safensis Strain 3A, a Heavy Metal-Resistant Bacterium Isolated from Contaminated Estuarine Sediment in Brazil.

3A was isolated from a contaminated estuarine sediment sample with mine tailing from the Samarco dam disaster, which occurred in 2015 in Minas Gerais State, Brazil. We report here a draft genome sequence (3.6 Mb) of this bacterial strain.

Enrichment of potential pathogens in marine microbiomes with different degrees of anthropogenic activity.

Anthropogenic activities in coastal marine ecosystems can lead to an increase in the abundance of potentially harmful microorganisms in the marine environment. To understand anthropogenic impacts on the marine microbiome, we first used publicly available microbial phylogenetic and functional data to establish a dataset of bacterial genera potentially related to pathogens that cause diseases (BGPRD) in marine organisms. Representatives of low-, medium- and highly impacted marine coastal environments were selected, and the abundance and composition of their microbial communities were determined by quantitative PCR and 16 S rRNA gene sequencing.

The composition of the bacterial community in the foam produced by Mahanarva fimbriolata is distinct from those at gut and soil.

The development of insects is strongly influenced by their resident microorganisms. Symbionts play key roles in insect nutrition, reproduction, and defense. Bacteria are important partners due to the wide diversity of their biochemical pathways that aid in the host development.

Draft Genomic Sequences of Streptomyces misionensis ACT66 and Streptomyces albidoflavus ACT77, Bacteria with Potential Application for Phytopathogen Biocontrol.

Here, we report the draft genomic sequences and annotation of ACT66 and ACT77, which are two bacteria with potential application for phytopathogen biocontrol.

Exploring bacterial functionality in mangrove sediments and its capability to overcome anthropogenic activity.

Mangrove forests are highly productive yet vulnerable ecosystems that act as important carbon sinks ("blue carbon"). The objective of this work was to analyze the impact of anthropogenic activities on microbiome structure and functioning. The metagenomic analysis revealed that the taxonomic compositions were grossly similar across all mangrove microbiomes.

Closed Genome Sequence of Bacillus paralicheniformis Strain CBMAI 1303, a Bacterium Applied for Phytopathogen Biocontrol.

We report the complete genome sequence and annotation of Bacillus paralicheniformis strain CBMAI 1303, a bacterium applied for phytopathogen biocontrol.

Hydrogen and electrical energy co-generation by a cooperative fermentation system comprising Clostridium and microbial fuel cell inoculated with port drainage sediment.

This research work has succeeded in recovering energy from glucose by generating H with the aid of a Clostridium beijerinckii strain and obtaining electrical energy from compounds present in the H fermentation effluent in a microbial fuel cell (MFC) seeded with native port drainage sediment. In the fermentation step, 49.5% of the initial glucose concentration (56 mmol/L) was used to produce 104 mmol/L H; 5, 33, 3, and 1 mmol/L acetate, butyrate, lactate, and ethanol also emerged, respectively.

The rates and players of denitrification, dissimilatory nitrate reduction to ammonia (DNRA) and anaerobic ammonia oxidation (anammox) in mangrove soils.

Mangroves are ecosystems located in the transition zone between land and sea, characterized by periodic flooding that confer to its unique characteristics. Little is known about the transformation of nutrients that occur during the organic matter degradation in this system. In this study, we monitor the nitrogen transformations in soils from three mangroves with distinct levels of contamination using labeled 15NO3-.

Closed Genome Sequence of Phytopathogen Biocontrol Agent Strain AGVL-005, Isolated from Soybean.

We report here the closed and near-complete genome sequence and annotation of strain AGVL-005, a bacterium isolated from soybean seeds in Brazil and used for phytopathogen biocontrol.

The parA Region of Broad-Host-Range PromA Plasmids Is a Carrier of Mobile Genes.

The ecological competences in microbiomes are driven by the adaptive capabilities present within microbiome members. Horizontal gene transfer (HGT) promoted by plasmids provides a rapid adaptive strategy to microbiomes, an interesting feature considering the constantly changing conditions in most environments. This study examined the parA locus, found in the highly promiscuous PromA class of plasmids, as the insertion site for incoming genes.

Anthropogenic impact on mangrove sediments triggers differential responses in the heavy metals and antibiotic resistomes of microbial communities.

Mangroves are complex and dynamic ecosystems highly dependent on diverse microbial activities. In the last decades, these ecosystems have been exposed to and affected by diverse human activities, such as waste disposal and accidental oil spills. Complex microbial communities inhabiting the soil and sediment of mangroves comprise microorganisms that have developed mechanisms to adapt to organic and inorganic contaminants.

Linking the Composition of Bacterial and Archaeal Communities to Characteristics of Soil and Flora Composition in the Atlantic Rainforest.

The description of microbiomes as intrinsic fractions of any given ecosystem is an important issue, for instance, by linking their compositions and functions with other biotic and abiotic components of natural systems and hosts. Here we describe the archaeal and bacterial communities from soils of the Atlantic Rainforest in Brazil. Based on the comparison of three areas located along an altitudinal gradient-namely, Santa Virginia, Picinguaba and Restinga-we detected the most abundant groups of Bacteria (Acidobacteria and Proteobacteria) and Archaea (Thaumarchaeota, Crenarchaeota and Euryarchaeota).

Different effects of transgenic maize and nontransgenic maize on nitrogen-transforming archaea and bacteria in tropical soils.

The composition of the rhizosphere microbiome is a result of interactions between plant roots, soil, and environmental conditions. The impact of genetic variation in plant species on the composition of the root-associated microbiota remains poorly understood. This study assessed the abundances and structures of nitrogen-transforming (ammonia-oxidizing) archaea and bacteria as well as nitrogen-fixing bacteria driven by genetic modification of their maize host plants.

Screening of endoglucanase-producing bacteria in the saline rhizosphere of Rhizophora mangle.

In screening the culturable endoglucanase-producing bacteria in the rhizosphere of Rhizophora mangle, we found a prevalence of genera Bacillus and Paenibacillus. These bacteria revealed different activities in endoglucolysis and biofilm formation when exposed to specific NaCl concentrations, indicating modulated growth under natural variations in mangrove salinity.

Endo- and exoglucanase activities in bacteria from mangrove sediment.

The mangrove ecosystem is an unexplored source for biotechnological applications. In this unique environment, endemic bacteria have the ability to thrive in the harsh environmental conditions (salinity and anaerobiosis), and act in the degradation of organic matter, promoting nutrient cycles. Thus, this study aimed to assess the cellulolytic activities of bacterial groups present in the sediment from a mangrove located in Ilha do Cardoso (SP, Brazil).

Sulphur-oxidizing and sulphate-reducing communities in Brazilian mangrove sediments.

Mangrove soils are anaerobic environments rich in sulphate and organic matter. Although the sulphur cycle is one of the major actors in this ecosystem, little is known regarding the sulphur bacteria communities in mangrove soils. We investigated the abundance, composition and diversity of sulphur-oxidizing (SOB) and sulphate-reducing (SRB) bacteria in sediments from three Brazilian mangrove communities: two contaminated, one with oil (OilMgv) and one with urban waste and sludge (AntMgv), and one pristine (PrsMgv).

Different selective effects on rhizosphere bacteria exerted by genetically modified versus conventional potato lines.

Background: In this study, we assessed the actively metabolizing bacteria in the rhizosphere of potato using two potato cultivars, i.e. the genetically-modified (GM) cultivar Modena (having tubers with altered starch content) and the near-isogenic non-GM cultivar Karnico.

Spatial and temporal variation of archaeal, bacterial and fungal communities in agricultural soils.

Background: Soil microbial communities are in constant change at many different temporal and spatial scales. However, the importance of these changes to the turnover of the soil microbial communities has been rarely studied simultaneously in space and time.

Methodology/principal Findings: In this study, we explored the temporal and spatial responses of soil bacterial, archaeal and fungal β-diversities to abiotic parameters.

Temporal dynamics of microbial communities in the rhizosphere of two genetically modified (GM) maize hybrids in tropical agrosystems.

The use of genetically modified (GM) plants still raises concerns about their environmental impact. The present study aimed to evaluate the possible effects of GM maize, in comparison to the parental line, on the structure and abundance of microbial communities in the rhizosphere. Moreover, the effect of soil type was addressed.

Endophytic bacteria isolated from orchid and their potential to promote plant growth.

Twelve endophytic bacteria were isolated from the meristem of in vitro Cymbidium eburneum orchid, and screened according to indole yield quantified by colorimetric assay, in vitro phosphate solubilization, and potential for plant growth promotion under greenhouse conditions. Eight strains with positive results were classified into the genus Paenibacillus by FAME profile, and evaluated for their ability to increase survival and promote the growth of in vitro germinated Cattleya loddigesii seedlings during the acclimatization process. The obtained results showed that all strains produced detectable indole levels and did not exhibit potential for solubilizing inorganic phosphate.

Abundance and genetic diversity of nifH gene sequences in anthropogenically affected Brazilian mangrove sediments.

Although mangroves represent ecosystems of global importance, the genetic diversity and abundance of functional genes that are key to their functioning scarcely have been explored. Here, we present a survey based on the nifH gene across transects of sediments of two mangrove systems located along the coast line of São Paulo state (Brazil) which differed by degree of disturbance, i.e.