Acacia longifolia is one of the most aggressive invaders worldwide whose invasion is potentiated after a fire, a common perturbation in Mediterranean climates. As a legume, this species establishes symbioses with nitrogen-fixing bacteria inside root nodules; however, the overall microbial diversity is still unclear. In this study, we addressed root nodules’ structure and biodiversity through histology and Next-Generation Sequencing, targeting 16S and 25S-28S rDNA genes for bacteria and fungi, respectively. We wanted to evaluate the effect of fire in root nodules from 1-year-old saplings, by comparing unburnt and burnt sites. We found that although having the same general structure, after a fire event, nodules had a higher number of infected cells and greater starch accumulation. Starch accumulated in uninfected cells can be a possible carbon source for the microbiota. Regarding diversity, Bradyrhizobium was dominant in both sites (ca. 77%), suggesting it is the preferential partner, followed by Tardiphaga (ca. 9%), a non-rhizobial Alphaproteobacteria, and Synechococcus, a cyanobacteria (ca. 5%). However, at the burnt site, additional N-fixing bacteria were included in the top 10 genera, highlighting the importance of this process. Major differences were found in the mycobiome, which was diverse in both sites and included genera mostly described as plant endophytes. Coniochaeta was dominant in nodules from the burnt site (69%), suggesting its role as a facilitator of symbiotic associations. We highlight the presence of a large bacterial and fungal community in nodules, suggesting nodulation is not restricted to nitrogen fixation. Thus, this microbiome can be involved in facilitating A. longifolia invasive success.

Faecal Microbiota Transplantation (FMT) is a promising strategy for modulating the gut microbiome. We aimed to assess the effect of the oral administration of capsules containing lyophilised faeces on dogs with diarrhoea for 2 months as well as evaluate their long-term influence on animals’ faecal consistency and intestinal microbiome. This pilot study included five dogs: two used as controls and three with diarrhoea. Animals were evaluated for four months by performing a monthly faecal samples collection and physical examination, which included faecal consistency determination using the Bristol scale. The total number of viable bacteria present in the capsules was quantified and their bacterial composition was determined by 16S rRNA gene sequencing, which was also applied to the faecal samples. During the assay, no side effects were reported. Animals’ faecal consistency improved and, after ending capsules administration, Bristol scale values remained stable in two of the three animals. The animals’ microbiome gradually changed toward a composition associated with a balanced microbiota. After FMT, a slight shift was observed in its composition, but the capsules’ influence remained evident during the 4-month period. Capsules administration seems to have a positive effect on the microbiota modulation; however, studies with more animals should be performed to confirm our observations.

Background Freshwater ecosystems play a vital role for humans and more-than-humans, and their study can elucidate their dynamic state throughout time. However, there is not much knowledge about the microbial profiles and their relevance for the ecosystem balance is still unclear. Methods In this Brief Report three freshwater samples collected in the Tagus River north margin were analysed through 16S-targeted nanopore sequencing and by customized bioinformatics pipeline. Results Our results revealed a consensual microbial profile with Candidatus Pelagibacter, Egibacter, and Ralstonia as the most abundant genera. Additionally, through a literature review we found that the ecosystem services provided by these genera are mostly related to organic matter decomposition. Conclusions Despite the need for a more robust sampling and analyses, we conclude that there is potential to use microbial profile approaches to help define the relevant microbial biomarkers to clarify the ecosystem services in the Tagus River freshwater ecosystem.

The widespread use of Recycled Manure Solids (RMS) as cow bedding material is not without risks, since cattle manure may act as a vehicle for pathogenic and antimicrobial resistant bacteria dissemination. Thus, our aim was to evaluate RMS-supplemented with a pine biochar produced in Portugal as a new cow bedding material, since the use of biochar has been shown to have the potential to mitigate the impact of relevant bacterial species when added to animal manure microbiota. Our experimental setup consisted on fresh RMS samples that were collected on a commercial dairy farm and placed in naturally-ventilated containers for a total of 4 groups: 1-non-supplemented RMS; 2-RMS supplemented with 2.5% (wt/wt) of biochar; 3-RMS supplemented with 5% (wt/wt) of biochar; and 4-RMS supplemented with 10% (wt/wt) of biochar. Sampling was performed at 4 different incubation times (0, 5, 15 and 30 d) and in 2 distinct seasons: April-May (humid season) and June-July (dry season). The resulting 32 samples were subjected to DNA extraction and their microbiome profile determined through complete 16S rDNA gene sequencing using Nanopore next-generation sequencing. We observed that biochar supplementation clearly altered the microbiome of RMS, which was reflected in changes in populations' diversity and their relative abundance of relevant pathogenic bacteria. In particular, we found that long-term storage (30 d) was more beneficial than short-term storage, an effect that was more evident for samples supplemented with 2.5% or 5% biochar. In both seasons, those concentrations of biochar led to a decrease in the levels of several mastitis-causing agents (Enterobacteriaceae, streptococci, enterococci and staphylococci). In addition, we also observed a reduction in the levels of Salmonella spp. and Gram-positive bacilli in the biochar-supplemented samples. Unexpectedly, however, those same conditions yielded an increase in the abundance of Brucella spp., a group which includes important infectious agents, highlighting the need for a deeper evaluation of the impact of biochar supplementation of RMS to ensure the future safe and sustainable use of this environmental-friendly resource in animal production.

The Eurasian griffon vulture (Gyps fulvus), a widely distributed scavenger, plays a crucial role in ecosystem health by consuming decomposing carcasses. Scavengers have adapted to avoid disease from the rotting carrion they feed on, probably through a specialized gut microbiome. This study aimed to characterize the gut microbiome of G. fulvus (n = 8) present in two rehabilitation centers in mainland Portugal and evaluate their potential as reservoirs of pathogens. Samples were studied through high-throughput 16S rDNA amplicon sequencing of the hypervariable V3-V4 regions and further analyzed using the Qiime2 bioinformatics platform. Our results showed that factors such as sex, location, and time of sampling did not significantly affect the gut microbiome of the griffon vulture. Its composition was highly similar to that of phylogenetically closed animals. However, several potential human and veterinary pathogens were identified. In conclusion, the gut microbiome of Gyps fulvus in rehabilitation centers is not significantly altered by stress associated with captivity. Its composition is similar to that of other vultures and scavengers due to their identic diet and needs, suggesting a well-conserved functional gut microbiome, which seems to be influenced by season. The potential risks posed by the identified pathogens to humans and other animals should be further investigated.

Background Freshwater ecosystems play a vital role for hosting life, and their study can elucidate their dynamic state throughout time. However, there is not much knowledge about the microbial profiles and their relevance for the ecosystem balance is still unclear. Methods In this Brief Report three freshwater samples collected in the Tagus River north margin were analysed through 16S-targeted nanopore sequencing and by customized bioinformatics pipeline. Results Our results revealed a consensual microbial profile with Candidatus Pelagibacter, Egibacter, and Ralstonia as the most abundant genera. Additionally, through a literature review we found that the ecosystem services provided by these genera are mostly related to organic matter decomposition. Conclusions Despite the need for a more robust sampling and analyses, we conclude that there is potential to use microbial profile approaches to help define the relevant microbial biomarkers to clarify the ecosystem services in the Tagus River freshwater ecosystem.