RESUMO
The bacterial community from a cooling water system was investigated through culture-dependent and independent strategies, and the responses of planktonic and sessile bacteria (grown in glass slides and stainless-steel coupons) to antimicrobials of industrial and clinical use were assessed. The morphotypes with higher biofilm-forming potential were Pseudoxanthomonas sp., Rheinheimera sp., Aeromonas sp. and Staphylococcus sp., and the first also exhibited lower susceptibility to all antibiotics and biocides tested. 16S rRNA high throughput sequencing indicated that Pseudomonadota (77.1% on average, sd 11.1%), Bacteroidota (8.4, sd 5.7%), and Planctomycetota (3.0, sd 1.3%) were the most abundant phyla. KEGG orthologs associated with antibiotics and biocide resistance were abundant in all samples. Although the minimum inhibitory and bactericidal concentrations were generally higher for biofilms, morphotypes in planktonic form also showed high levels of resistance, which could be associated with biofilm cells passing into the planktonic phase. Overall, monochloramine was the most effective biocide.
Assuntos
Bactérias , Biofilmes , Microbiota , Plâncton , Biofilmes/efeitos dos fármacos , Plâncton/efeitos dos fármacos , Microbiota/efeitos dos fármacos , Bactérias/efeitos dos fármacos , Bactérias/classificação , Bactérias/genética , RNA Ribossômico 16S/genética , Desinfetantes/farmacologia , Testes de Sensibilidade Microbiana , Antibacterianos/farmacologia , Microbiologia da ÁguaRESUMO
BACKGROUND: Lichens are micro-ecosystems relying on diverse microorganisms for nutrient cycling, environmental adaptation, and structural support. We investigated the spatial-scale dependency of factors shaping the ecological processes that govern lichen-associated bacteria. We hypothesize that lichens function as island-like habitats hosting divergent microbiomes and promoting landscape gamma-diversity. Three microenvironments -thalli, substrates, and neighboring soils- were sampled from four geographically overlapping species of Peltigera cyanolichens, spanning three bioclimatic zones in the Chilean Patagonia, to determine how bacterial diversity, assembly processes, ecological drivers, interaction patterns, and niche breadth vary among Peltigera microenvironments on a broad geographical scale. RESULTS: The hosts' phylogeny, especially that of the cyanobiont, alongside climate as a secondary factor, impose a strong ecological filtering of bacterial communities within Peltigera thalli. This results in deterministically assembled, low diverse, and phylogenetically convergent yet structurally divergent bacterial communities. Host evolutionary and geographic distances accentuate the divergence in bacterial community composition of Peltigera thalli. Compared to soil and substrate, Peltigera thalli harbor specialized and locally adapted bacterial taxa, conforming sparse and weak ecological networks. CONCLUSIONS: The findings suggest that Petigera thalli create fragmented habitats that foster landscape bacterial gamma-diversity. This underscores the importance of preserving lichens for maintaining a potential reservoir of specialized bacteria.
RESUMO
The global market of sweet potato (Ipomoea batatas (L.) Lam.) is continuously growing and, consequently, demands greater productivity from the agricultural sector. The use of biofertilizers facilitates plant growth by making essential nutrients available to crops or providing resistance against different abiotic and biotic factors. The strains Bacillus safensis T052-76 and Bacillus velezensis T149-19 have previously been inoculated in the sweet potato cultivar Ourinho, showing positive effects on plant shoot growth and inhibiting the phytopathogen Plenodomus destruens. To elucidate the effects of these strains on sweet potato growth, four different cultivars of sweet potato were selected: Capivara, IAPAR 69, Rosinha de Verdan and Roxa. The plants were grown in pots in a greenhouse and inoculated with the combined strains according to a randomized block design. A control (without the inoculation of both strains) was also used. A slight positive effect of the inoculation of the two Bacillus strains was observed on the aerial parts of some of the cultivars. An increase in the fresh weight of the sweet potatoes of the inoculated plants was obtained, varying from 2.7 to 11.4 %. The number of sweet potatoes obtained from the inoculated cultivars IAPAR 69 and Roxa increased 15.2 % and 16.7 %, respectively. The rhizosphere soil of each cultivar was further sampled for DNA extraction, and the 16S rRNA gene metabarcoding technique was used to determine how the introduction of these Bacillus strains influenced the rhizosphere bacterial community. The bacterial communities of the four different cultivars were dominated by Actinobacteria, Proteobacteria and Firmicutes. Nonmetric multidimensional scaling (NMDS) revealed that the rhizosphere bacterial communities of plants inoculated with Bacillus strains were more similar to each other than to the bacterial communities of uninoculated plants. This study highlights the contribution of these Bacillus strains to the promotion of sweet potato growth.
RESUMO
Mangroves are coastal environments that provide resources for adjacent ecosystems due to their high productivity, organic matter decomposition, and carbon cycling by microbial communities in sediments. Since the industrial revolution, the increase of Greenhouse Gases (GHG) released due to fossil fuel burning led to many environmental abnormalities such as an increase in average temperature and ocean acidification. Based on the hypothesis that climate change modifies the microbial diversity associated with decaying organic matter in mangrove sediments, this study aimed to evaluate the microbial diversity under simulated climate change conditions during the litter decomposition process and the emission of GHG. Thus, microcosms containing organic matter from the three main plant species found in mangroves throughout the State of São Paulo, Brazil (Rhizophora mangle, Laguncularia racemosa, and Avicennia schaueriana) were incubated simulating climate changes (increase in temperature and pH). The decay rate was higher in the first seven days of incubation, but the differences between the simulated treatments were minor. GHG fluxes were higher in the first ten days and higher in samples under increased temperature. The variation in time resulted in substantial impacts on α-diversity and community composition, initially with a greater abundance of Gammaproteobacteria for all plant species despite the climate conditions variations. The PCoA analysis reveals the chronological sequence in ß-diversity, indicating the increase of Deltaproteobacteria at the end of the process. The GHG emission varied in function of the organic matter source with an increase due to the elevated temperature, concurrent with the rise in the Deltaproteobacteria population. Thus, these results indicate that under the expected climate change scenario for the end of the century, the decomposition rate and GHG emissions will be potentially higher, leading to a harmful feedback loop of GHG production. This process can happen independently of an impact on the bacterial community structure due to these changes.
RESUMO
Soil bacterial communities play a critical role in shaping soil stability and formation, exhibiting a dynamic interaction with local climate and soil depth. We employed an innovative DNA separation method to characterize microbial assemblages in low-biomass environments such as deserts and distinguish between intracellular DNA (iDNA) and extracellular DNA (eDNA) in soils. This approach, combined with analyses of physicochemical properties and co-occurrence networks, investigated soil bacterial communities across four sites representing diverse climatic gradients (i.e., arid, semi-arid, Mediterranean, and humid) along the Chilean Coastal Cordillera. The separation method yielded a distinctive unimodal pattern in the iDNA pool alpha diversity, increasing from arid to semi-arid climates and decreasing in humid environments, highlighting the rapid feedback of the iDNA community to increasing soil moisture. In the arid region, harsh surface conditions restrict bacterial growth, leading to peak iDNA abundance and diversity occurring in slightly deeper layers than the other sites. Our findings confirmed the association between specialist bacteria and ecosystem-functional traits. We observed transitions from Halomonas and Delftia, resistant to extreme arid environments, to Class AD3 and the genus Bradyrhizobium, associated with plants and organic matter in humid environments. The distance-based redundancy analysis (dbRDA) analysis revealed that soil pH and moisture were the key parameters that influenced bacterial community variation. The eDNA community correlated slightly better with the environment than the iDNA community. Soil depth was found to influence the iDNA community significantly but not the eDNA community, which might be related to depth-related metabolic activity. Our investigation into iDNA communities uncovered deterministic community assembly and distinct co-occurrence modules correlated with unique bacterial taxa, thereby showing connections with sites and key environmental factors. The study additionally revealed the effects of climatic gradients and soil depth on living and dead bacterial communities, emphasizing the need to distinguish between iDNA and eDNA pools.
Assuntos
Bactérias , Clima , Microbiota , Microbiologia do Solo , Solo , Chile , Bactérias/classificação , Solo/química , Ecossistema , Monitoramento Ambiental , BiodiversidadeRESUMO
Assessing the bacterial community composition across cacao crops is important to understand its potential role as a modulator of cadmium (Cd) translocation to plant tissues under field conditions; Cd mobility between soil and plants is a complex and multifactorial problem that cannot be captured only by experimentation. Although microbes have been shown to metabolize and drive the speciation of Cd under controlled conditions, regardless of the link between soil bacterial community (SBC) dynamics and Cd mobilization in the rhizosphere, only a few studies have addressed the relationship between soil bacterial community composition (SBCC) and Cd content in cacao seeds (Cdseed). Therefore, this study aimed to explore the association between SBCC and different factors influencing the distribution of Cd across cacao crop systems. This study comprised 225 samples collected across five farms, where we used an amplicon sequencing approach to characterize the bacterial community composition. The soil Cd concentration alone (Cdsoil) was a poor predictor of Cdseed. Still, we found that this relationship was more apparent when the variation within farms was controlled, suggesting a role of heterogeneity within farms in modulating Cd translocation and, thus, seed Cd content. Our results provide evidence of the link between soil bacterial communities and the distribution of Cd across Colombian cacao crops, and highlight the importance of incorporating fine-spatial-scale studies to advance the understanding of factors driving Cd uptake and accumulation in cacao plants. IMPORTANCE: Cadmium (Cd) content in cacao crops is an issue that generates interest due to the commercialization of chocolate for human consumption. Several studies provided evidence about the non-biological factors involved in its translocation into the cacao plant. However, factors related to this process, including soil bacterial community composition (SBCC), still need to be addressed. It is well known that soil microbiome could impact compounds' chemical transformation, including Cd, on the field. Here, we found the first evidence of the link between soil bacterial community composition and Cd concentration in cacao soils and seeds. It highlights the importance of including the variation of bacterial communities to assess the factors driving the Cd translocation into cacao seeds. Moreover, the results highlight the relevance of the spatial heterogeneity within and across cacao farms, influencing the variability of Cd concentrations.
Assuntos
Bactérias , Cacau , Cádmio , Produtos Agrícolas , Microbiota , Rizosfera , Sementes , Microbiologia do Solo , Poluentes do Solo , Cádmio/metabolismo , Cádmio/análise , Cacau/microbiologia , Cacau/metabolismo , Bactérias/classificação , Bactérias/genética , Bactérias/metabolismo , Bactérias/isolamento & purificação , Poluentes do Solo/metabolismo , Poluentes do Solo/análise , Colômbia , Produtos Agrícolas/microbiologia , Produtos Agrícolas/metabolismo , Sementes/microbiologia , Sementes/metabolismo , Solo/químicaRESUMO
Antibiotic resistance genes (ARGs) are a major threat to human and environmental health. This study investigated the occurrence and distribution of ARGs in Lake Cajititlán, a hypereutrophic subtropical lake in Mexico contaminated by anthropogenic sources (urban wastewater and runoff from crop and livestock production). ARGs (a total of 475 genes) were detected in 22 bacterial genera, with Pseudomonas (144 genes), Stenotrophomonas (88 genes), Mycobacterium (54 genes), and Rhodococcus (27 genes) displaying the highest frequencies of ARGs. Among these, Pseudomonas aeruginosa and Stenotrophomonas maltophilia showed the highest number of ARGs. The results revealed a diverse array of ARGs, including resistance to macrolides (11.55 %), aminoglycosides (8.22 %), glycopeptides (6.22 %), tetracyclines (4 %), sulfonamides (4 %), carbapenems (1.11 %), phenicols (0.88 %), fluoroquinolones (0.44 %), and lincosamides (0.22 %). The most frequently observed ARGs were associated with multidrug resistance (63.33 %), with MexF (42 genes), MexW (36 genes), smeD (31 genes), mtrA (25 genes), and KHM-1 (22 genes) being the most common. Lake Cajititlán is a recreational area for swimming, fishing, and boating, while also supporting irrigation for agriculture and potentially acting as a drinking water source for some communities. This raises concerns about the potential for exposure to antibiotic-resistant bacteria through these activities. The presence of ARGs in Lake Cajititlán poses a significant threat to both human and environmental health. Developing strategies to mitigate the risks of antibiotic resistance, including improving wastewater treatment, and promoting strategic antibiotic use and disposal, is crucial. This study represents a significant advancement in the understanding of antibiotic resistance dynamics in a hypereutrophic subtropical lake in a developing country, providing valuable insights for the scientific community and policymakers.
Assuntos
Resistência Microbiana a Medicamentos , Monitoramento Ambiental , Lagos , Lagos/microbiologia , Resistência Microbiana a Medicamentos/genética , México , Antibacterianos/farmacologia , Metagenômica , Genes Bacterianos , Farmacorresistência Bacteriana/genética , Águas Residuárias/microbiologia , Bactérias/efeitos dos fármacos , Bactérias/genética , Poluentes Químicos da Água/análiseRESUMO
Antipsychotics (APs) have been increasingly prescribed for psychiatric disorders from schizophrenia to disruptive behavioral conditions. These drugs have been associated with considerable side effects, such as weight gain, and increasing evidence has also indicated that its use impacts gut microbiota (GM), although this connection is still little understood. To assess APs effects on the GM of patients starting or ongoing treatment, a systematic review was carried out in PubMed and Scopus databases. Twelve articles were considered eligible for the review, which investigated the effects of risperidone (5 studies), quetiapine (3), amilsupride (1), olanzapine (1), and unspecified atypical drugs (2). Eleven reported changes in GM in response to APs, and associations between the abundance of bacterial groups and different metabolic parameters were described by most of them. However, the studies were noticeably heterogeneous considering design, methods, and results. In this way, the effects of APs on GM composition and diversity were inconclusive. Despite the uncertain interactions, a more comprehensive understanding on how microbiota is affected by APs may help to optimize treatment, potentially minimizing side effects and improving adherence to treatment.
Assuntos
Antipsicóticos , Microbioma Gastrointestinal , Humanos , Microbioma Gastrointestinal/efeitos dos fármacos , Antipsicóticos/farmacologiaRESUMO
In recent years, numerous studies have indicated that the combination of organic and inorganic fertilizers can effectively improve soil fertility and soil productivity. Distillers' grain (DG), the primary by-product of Chinese spirits production, has a high utilization value for producing organic fertilizer. We investigated the effects of distillers' grain organic fertilizer (DGOF) on soil chemical properties and microbial community composition, as well as the effects of chemical properties on the abundance of keystone species. The results indicated that the application of DGOF significantly increased tobacco yield by 14.8% and mainly affected the composition rather than the alpha diversity of the bacterial community. Ten amplicon sequence variants (ASVs) were identified as keystone species in the bacterial communities, and most of their relative abundance was influenced by the DGOF addition through affecting soil chemical properties. Our results elucidated the alterations in soil chemical properties and microbial community composition resulting from DGOF application, which is of great importance to better understand the relationship between DGOF and soil microorganisms in the flue-cured tobacco cultivation field.
Assuntos
Microbiota , Solo , Solo/química , Fertilizantes/análise , Bactérias/genética , Grão Comestível , Microbiologia do SoloRESUMO
Endophytic bacteria play a crucial role in plant development and adaptation, and the knowledge of how endophytic bacteria assemblage is influenced by cultivation site and plant genotype is an important step to achieve microbiome manipulation. This work aimed to study the roots and stems of endophytic bacteriome of four maize genotypes cultivated in two regions of the semi-arid region of Pernambuco - Brazil. Our hypothesis is that the endophytic community assemblage will be influenced by plant genotypes and cultivation region. Metabarcoding sequencing data revealed significant differences in alfa diversity in function of both factors, genotypes, and maize organs. Beta diversity analysis showed that the bacterial communities differ mainly in function of the plant organ. The most abundant genera found in the samples were Leifsonia, Bacillus, Klebsiella, Streptomyces, and Bradyrhizobium. To understand ecological interactions within each compartment, we constructed co-occurrence network for each organ. This analysis revealed important differences in network structure and complexity and suggested that Leifsonia (the main genera found) had distinct ecological roles depending on the plant organ. Our data showed that root endophytic maize bacteria would be influenced by cultivation site, but not by genotype. We believe that, collectively, our data not only characterize the bacteriome associated with this plant and how different factors shape it, but also increase the knowledge to select potential bacteria for bioinoculant production.