The impact of land-use changes and management intensification on bacterial communities in the last decade: a review.

In the last decade, advances in soil bacterial ecology have contributed to increasing agricultural production. Brazil is the world leading agriculture producer and leading soil biodiversity reservoir. Meanwhile, there is still a significant gap in the knowledge regarding the soil microscopic life and its interactions with agricultural practices, and the replacement of natural vegetation by agroecosystems is yet to be unfolded. Through high throughput DNA sequencing, scientists are now exploring the complexity of soil bacterial communities and their relationship with soil and environmental characteristics. This study aimed to investigate the progress of bacterial ecology studies in Brazil over the last 10 years, seeking to understand the effect of the conversion of natural vegetation in agricultural systems on the diversity and structure of the soil microbial communities. We conducted a systematic search for scientific publication databases. Our systematic search has matched 62 scientific articles from three different databases. Most of the studies were placed in southeastern and northern Brazil, with no records of studies about microbial ecology in 17 out of 27 Brazilian states. Out of the 26 studies that examined the effects of replacing natural vegetation with agroecosystems, most authors concluded that changes in soil pH and vegetation cover replacement were the primary drivers of shifts in microbial communities. Understanding the ecology of the bacteria inhabiting Brazilian soils in agroecosystems is paramount for developing more efficient soil management strategies and cleaner agricultural technologies.

Interaction between methanotrophy and gastrointestinal nematodes infection on the rumen microbiome of lambs.

Complex cross-talk occurs between gastrointestinal nematodes and gut symbiotic microbiota, with consequences for animal metabolism. To investigate the connection between methane production and endoparasites, this study evaluated the effect of mixed infection with Haemonchus contortus and Trichostrongylus colubriformis on methanogenic and methanotrophic community in rumen microbiota of lambs using shotgun metagenomic and real-time quantitative PCR (qPCR). The rumen content was collected from six Santa Inês lambs, (7 months old) before and after 42 days infection by esophageal tube. The metagenomic analysis showed that the infection affected the microbial community structure leading to decreased abundance of methanotrophs bacteria, i.e. α-proteobacteria and ß-proteobacteria, anaerobic methanotrophic archaea (ANME), protozoa, sulfate-reducing bacteria, syntrophic bacteria with methanogens, geobacter, and genes related to pyruvate, fatty acid, nitrogen, and sulfur metabolisms, ribulose monophosphate cycle, and Entner-Doudoroff Pathway. Additionally, the abundance of methanogenic archaea and the mcrA gene did not change. The co-occurrence networks enabled us to identify the interactions between each taxon in microbial communities and to determine the reshaping of rumen microbiome associations by gastrointestinal nematode infection. Besides, the correlation between ANMEs was lower in the animal's postinfection. Our findings suggest that gastrointestinal parasites potentially lead to decreased methanotrophic metabolism-related microorganisms and genes.

Grazing exclusion-induced changes in soil fungal communities in a highly desertified Brazilian dryland.

Soil desertification poses a critical ecological challenge in arid and semiarid climates worldwide, leading to decreased soil productivity due to the disruption of essential microbial community processes. Fungi, as one of the most important soil microbial communities, play a crucial role in enhancing nutrient and water uptake by plants through mycorrhizal associations. However, the impact of overgrazing-induced desertification on fungal community structure, particularly in the Caatinga biome of semiarid regions, remains unclear. In this study, we assessed the changes in both the total fungal community and the arbuscular mycorrhizal fungal community (AMF) across 1. Natural vegetation (native), 2. Grazing exclusion (20 years) (restored), and 3. affected by overgrazing-induced degradation (degraded) scenarios. Our assessment, conducted during both the dry and rainy seasons in Irauçuba, Ceará, utilized Internal Transcribed Spacer (ITS) gene sequencing via Illumina® platform. Our findings highlighted the significant roles of the AMF families Glomeraceae (∼71% of the total sequences) and Acaulosporaceae (∼14% of the total sequences) as potential key taxa in mitigating climate change within dryland areas. Moreover, we identified the orders Pleosporales (∼35% of the total sequences) and Capnodiales (∼21% of the total sequences) as the most abundant soil fungal communities in the Caatinga biome. The structure of the total fungal community differed when comparing native and restored areas to degraded areas. Total fungal communities from native and restored areas clustered together, suggesting that grazing exclusion has the potential to improve soil properties and recover fungal community structure amid global climate change challenges.

Endophytic Aspergillii and Penicillii from medicinal plants: a focus on antimicrobial and multidrug resistant pathogens inhibitory activity.

The rise of multidrug resistance among microorganisms, where they develop resistance against formerly efficacious drugs, has led to increased disease prevalence and mortality rates, posing a growing challenge. Globally, antibiotic resistance has made a significant impact, causing millions of fatalities each year. Endophytic fungi have gained considerable attention in research due to their potential to produce a wide variety of secondary metabolites, including natural substances with antimicrobial capabilities. The genera Aspergillus and Penicillium stand out as the most prevalent species of endophytic fungi. Filamentous fungi, such as these are responsible for the production of 45% of known microbial metabolites. This review focuses on exploring the bioactive substances produced by endophytic fungi from these two genera, particularly in conjunction with medicinal plants. Emphasis is placed on their antimicrobial activity and their ability to inhibit multidrug-resistant pathogens. As the need for alternative treatments to combat drug-resistant infections continues to grow, endophytic fungi have the potential to provide a valuable source of bioactive molecules for medical applications.

Desafios da atenção primária em João Pessoa contra o coronavírus na perspectiva do usuário / User perspective on the challenges of primary care against the coronavirus in joão pessoa / Desafíos de la atención primaria en João Pessoa frente al coronavirus desde la perspectiva del usuario

No cenário pandêmico, o Sistema Único de Saúde precisou reinventar seus processos de trabalho, estabelecer novos fluxos de atendimento e fortalecer suas redes de atenção para prevenir e reduzir o contágio do vírus. Este estudo visa avaliar, do ponto de vista dos usuários, os desafios da Atenção Primária à Saúde em João Pessoa, Paraíba, no controle do coronavírus. Trata-se de uma pesquisa transversal descritiva, com abordagem qualiquantitativa, que utilizou questionários elaborados no aplicativo Google Forms® e analisou os resultados por meio da estatística descritiva simples. Diante disso, foram selecionados quarenta usuários da Unidade Básica de Saúde, escolhidos durante as visitas dos pesquisadores à unidade localizada no bairro Cristo Redentor, em João Pessoa, entre março de 2020 e março de 2022. Ao serem questionados acerca da qualidade do preparo assistencial da unidade em relação ao atendimento dos casos não suspeitos, alguns usuários, ainda que uma parcela minoritária, fizeram uma avaliação negativa, uma vez que sentiram falta do cuidado assistencial. Além disso, conforme os relatos dos usuários, foram escassas as ações das equipes na busca ativa de sintomas respiratórios em grupos de risco. No tocante à comunicação da unidade com a comunidade durante a pandemia, foram relatadas dificuldades em contatar o posto, o que traz à tona a importância do agente comunitário de saúde e abre uma discussão sobre telessaúde, além de destacar a inviabilização da longitudinalidade e integralidade do cuidado durante esse período. Diante da crise sanitária global, nota-se que o confronto à pandemia pressupôs uma reestruturação da rede assistencial, na qual o verdadeiro desafio da Atenção Primária foi aprofundar seus atributos.

In the pandemic scenario, the Unified Health System had to reinvent its work processes, establishing new service flows and strengthening its care networks to prevent and reduce the virus spread. This study evaluates, from the user perspective, the challenges faced by Primary Health Care in João Pessoa, Paraíba, in controlling the coronavirus. A descriptive, qualitative-quantitative cross-sectional research was conducted by applying questionnaires prepared using Google Forms®. Results were analyzed using simple descriptive statistics. A total of 40 Basic Health Unit users were selected during researchers' visits to the Cristo Redentor neighborhood unit between March 2020 and March 2022. When asked about the unit's care quality regarding non-suspect cases, some users made a negative evaluation, since the attention dispended felt lacking. Moreover, according to the participants, the teams seldomly actively searched for respiratory symptoms in risk groups. Regarding the unit's communication with the community during the pandemic, users reported difficulties in contacting the unit, which brings up the importance of community health agents and opens the discussion about telemedicine, as well as emphasizes the unfeasibility of care longitudinality and comprehensiveness during this period. Faced with a global health crisis, combating the pandemic required restructuring the care network, in which the real challenge of Primary Care was to further its attributes.

En el escenario de la pandemia, el Sistema Único de Salud necesitó reinventar sus procesos de trabajo, establecer nuevos flujos de servicios y fortalecer sus redes de atención para prevenir y mitigar la propagación del virus. Este estudio tiene como objetivo evaluar, desde el punto de vista de los usuarios, los desafíos de la atención primaria de salud en João Pessoa, Paraíba (Brasil), en el control del coronavirus. Se trata de una investigación descriptiva de corte transversal, con enfoque cualicuantitativo, que utilizó cuestionarios elaborados en la aplicación Google Forms y analizó los resultados mediante estadística descriptiva simple. Así, fueron seleccionados cuarenta usuarios de la Unidad Básica de Salud, elegidos durante las visitas de los investigadores a la unidad ubicada en el barrio Cristo Redentor, en João Pessoa, entre marzo de 2020 y marzo de 2022. Se evidenció una evaluación negativa, aunque minoritaria, al interrogatorio acerca de la calidad de la preparación asistencial de la unidad con relación a la atención de casos no sospechosos, ya que sintieron falta de atención. Además, según los reportes de los usuarios, hubo pocos informes de equipos que buscaran activamente síntomas respiratorios en grupos de riesgo. Respecto a la comunicación de la unidad con la comunidad durante la pandemia, se informaron dificultades para contactar a la unidad, lo que resalta la importancia del agente comunitario de salud y abre la discusión sobre la telesalud, además de poner de relieve la inviabilidad de la longitudinalidad e integralidad de la atención durante este período. Frente a la crisis sanitaria global, se constata que enfrentar la pandemia requirió una reestructuración de la red de atención, en la que el verdadero desafío de la atención primaria era profundizar sus atributos.

The interplay between the inoculation of plant growth-promoting rhizobacteria and the rhizosphere microbiome and their impact on plant phenotype.

Microbial inoculation stands as a pivotal strategy, fostering symbiotic relationships between beneficial microorganisms and plants, thereby enhancing nutrient uptake, bolstering resilience against environmental stressors, and ultimately promoting healthier and more productive plant growth. However, while the advantageous roles of inoculants are widely acknowledged, the precise and nuanced impacts of inoculation on the intricate interactions of the rhizosphere microbiome remain significantly underexplored. This study explores the impact of bacterial inoculation on soil properties, plant growth, and the rhizosphere microbiome. By employing various bacterial strains and a synthetic community (SynCom) as inoculants in common bean plants, the bacterial and fungal communities in the rhizosphere were assessed through 16 S rRNA and ITS gene sequencing. Concurrently, soil chemical parameters, plant traits, and gene expression were evaluated. The findings revealed that bacterial inoculation generally decreased pH and V%, while increasing H+Al and m% in the rhizosphere. It also decreased gene expression in plants related to detoxification, photosynthesis, and defense mechanisms, while enhancing bacterial diversity in the rhizosphere, potentially benefiting plant health. Specific bacterial strains showed varied impacts on rhizosphere microbiome assembly, predominantly affecting rhizospheric bacteria more than fungi, indirectly influencing soil conditions and plants. Notably, Paenibacillus polymyxa inoculation improved plant nitrogen (by 5.2%) and iron levels (by 28.1%), whereas Bacillus cereus boosted mycorrhization rates (by 70%). Additionally, inoculation led to increased complexity in network interactions within the rhizosphere (∼15%), potentially impacting plant health. Overall, the findings highlight the significant impact of introducing bacteria to the rhizosphere, enhancing nutrient availability, microbial diversity, and fostering beneficial plant-microbe interactions.

Redox conditions and biochar pyrolysis temperature affecting As and Pb biogeochemical cycles and bacterial community of sediment from mining tailings.

Despite the widespread use of biochar for soil and sediment remediation, little is known about the impact of pyrolysis temperature on the biogeochemistry of arsenic (As) and lead (Pb) and microorganisms in sediment under reducing conditions. In this study, we investigated the effects of pyrolysis temperature and the addition of glucose on the release and transformation of As and Pb, as well as their potential effects on the bacterial community in contaminated sediments. The addition of biochar altered the geochemical cycle of As, as it favors specific bacterial groups capable of changing species from As(V) to As(III) through fermentation, sulfate respiration and nitrate reduction. The carbon quality and content of N and S in solution shaped the pH and redox potential in a way that changed the microbial community, favoring Firmicutes and reducing Proteobacteria. This change played a fundamental role in the reductive dissolution of As and Pb minerals. The addition of biochar was the only efficient way to remove Pb, possibly as a function of its sorption and precipitation mechanisms. Such insights could contribute to the production or choice of high-efficiency biochar for the remediation of sediments subjected to redox conditions.

Short-term restoration practices change the bacterial community in degraded soil from the Brazilian semiarid.

Land degradation by deforestation adversely impacts soil properties, and long-term restoration practices have been reported to potentially reverse these effects, particularly on soil microorganisms. However, there is limited knowledge regarding the short-term effects of restoration on the soil bacterial community in semiarid areas. This study evaluates the bacterial community in soils experiencing degradation (due to slash-and-burn deforestation) and restoration (utilizing stone cordons and revegetation), in comparison to a native soil in the Brazilian semiarid region. Three areas were selected: (a) under degradation; (b) undergoing short-term restoration; and (c) a native area, and the bacterial community was assessed using 16S rRNA sequencing on soil samples collected during both dry and rainy seasons. The dry and rainy seasons exhibited distinct bacterial patterns, and native sites differed from degraded and restoration sites. Chloroflexi and Proteobacteria phyla exhibited higher prevalence in degraded and restoration sites, respectively, while Acidobacteria and Actinobacteria were more abundant in sites undergoing restoration compared to degraded sites. Microbial connections varied across sites and seasons, with an increase in nodes observed in the native site during the dry season, more edges and positive connections in the restoration site, and a higher occurrence of negative connections in the degradation site during the rainy season. Niche occupancy analysis revealed that degradation favored specialists over generalists, whereas restoration exhibited a higher prevalence of generalists compared to native sites. Specifically, degraded sites showed a higher abundance of specialists in contrast to restoration sites. This study reveals that land degradation impacts the soil bacterial community, leading to differences between native and degraded sites. Restoring the soil over a short period alters the status of the bacterial community in degraded soil, fostering an increase in generalist microbes that contribute to enhanced soil stability.

Soil fertility impact on recruitment and diversity of the soil microbiome in sub-humid tropical pastures in Northeastern Brazil.

Soil fertility is key point to pastures systems and drives the microbial communities and their functionality. Therefore, an understanding of the interaction between soil fertility and microbial communities can increase our ability to manage pasturelands and maintain their soil functioning and productivity. This study probed the influence of soil fertility on microbial communities in tropical pastures in Brazil. Soil samples, gathered from the top 20 cm of twelve distinct areas with diverse fertility levels, were analyzed via 16S rRNA sequencing. The soils were subsequently classified into two categories, namely high fertility (HF) and low fertility (LF), using the K-Means clustering. The random forest analysis revealed that high fertility (HF) soils had more bacterial diversity, predominantly Proteobacteria, Nitrospira, Chloroflexi, and Bacteroidetes, while Acidobacteria increased in low fertility (LF) soils. High fertility (HF) soils exhibited more complex network interactions and an enrichment of nitrogen-cycling bacterial groups. Additionally, functional annotation based on 16S rRNA varied between clusters. Microbial groups in HF soil demonstrated enhanced functions such as nitrate reduction, aerobic ammonia oxidation, and aromatic compound degradation. In contrast, in the LF soil, the predominant processes were ureolysis, cellulolysis, methanol oxidation, and methanotrophy. Our findings expand our knowledge about how soil fertility drives bacterial communities in pastures.

Genomic insights of Fictibacillus terranigra sp. nov., a versatile metabolic bacterium from Amazonian Dark Earths.

The Amazon rainforest, a hotspot for biodiversity, is a crucial research area for scientists seeking novel microorganisms with ecological and biotechnological significance. A key region within the Amazon rainforest is the Amazonian Dark Earths (ADE), noted for supporting diverse plant and microbial communities, and its potential as a blueprint for sustainable agriculture. This study delineates the isolation, morphological traits, carbon source utilization, and genomic features of Fictibacillus terranigra CENA-BCM004, a candidate novel species of the Fictibacillus genus isolated from ADE. The genome of Fictibacillus terranigra was sequenced, resulting in 16 assembled contigs, a total length of 4,967,627 bp, and a GC content of 43.65%. Genome annotation uncovered 3315 predicted genes, encompassing a wide range of genes linked to various metabolic pathways. Phylogenetic analysis indicated that CENA-BCM004 is a putative new species, closely affiliated with other unidentified Fictibacillus species and Bacillus sp. WQ 8-8. Moreover, this strain showcased a multifaceted metabolic profile, revealing its potential for diverse biotechnological applications. It exhibited capabilities to antagonize pathogens, metabolize multiple sugars, mineralize organic matter compounds, and solubilize several minerals. These insights substantially augment our comprehension of microbial diversity in ADE and underscore the potential of Fictibacillus terranigra as a precious resource for biotechnological endeavors. The genomic data generated from this study will serve as a foundational resource for subsequent research and exploration of the biotechnological capabilities of this newly identified species.

From desertification to restoration in the Brazilian semiarid region: Unveiling the potential of land restoration on soil microbial properties.

Land desertification poses a significant challenge in the Brazilian semiarid region, encompassing a substantial portion of the country. Within this region, the detrimental effects of human activities, particularly unsuitable anthropic actions, have resulted in diminished vegetation cover and an accelerated rate of soil erosion. Notably, practices such as overgrazing and the conversion of native forests into pasturelands have played a pivotal role in exacerbating the process of land desertification. Ultimately, land desertification results in significant losses of soil organic matter and microbial diversity. To address this pressing issue and contribute to the existing literature, various land restoration practices, such as grazing exclusion, cover crops, and terracing, have been implemented in the Brazilian semiarid. These practices have shown promising results in terms of enhancing soil fertility and restoring microbial properties. Nonetheless, their effectiveness in improving soil microbial properties in the Brazilian semiarid region remains a subject of ongoing study. Recent advances in molecular techniques have improved our understanding of microbial communities in lands undergoing desertification and restoration. In this review, we focus on assessing the effectiveness of these restoration practices in revitalizing soil microbial properties, with a particular emphasis on the soil microbiome and its functions. Through a critical assessment of the impact of these practices on soil microbial properties, our research aims to provide valuable insights that can help mitigate the adverse effects of desertification and promote sustainable development in this ecologically sensitive region.

Repeated exposure of wheat to the fungal root pathogen Bipolaris sorokiniana modulates rhizosphere microbiome assembly and disease suppressiveness.

BACKGROUND: Disease suppressiveness of soils to fungal root pathogens is typically induced in the field by repeated infections of the host plant and concomitant changes in the taxonomic composition and functional traits of the rhizosphere microbiome. Here, we studied this remarkable phenomenon for Bipolaris sorokiniana in two wheat cultivars differing in resistance to this fungal root pathogen. RESULTS: The results showed that repeated exposure of the susceptible wheat cultivar to the pathogen led to a significant reduction in disease severity after five successive growth cycles. Surprisingly, the resistant wheat cultivar, initially included as a control, showed the opposite pattern with an increase in disease severity after repeated pathogen exposure. Amplicon analyses revealed that the bacterial families Chitinophagaceae, Anaerolineaceae and Nitrosomonadaceae were associated with disease suppressiveness in the susceptible wheat cultivar; disease suppressiveness in the resistant wheat cultivar was also associated with Chitinophagaceae and a higher abundance of Comamonadaceae. Metagenome analysis led to the selection of 604 Biosynthetic Gene Clusters (BGCs), out of a total of 2,571 identified by AntiSMASH analysis, that were overrepresented when the soil entered the disease suppressive state. These BGCs are involved in the biosynthesis of terpenes, non-ribosomal peptides, polyketides, aryl polyenes and post-translationally modified peptides. CONCLUSION: Combining taxonomic and functional profiling we identified key changes in the rhizosphere microbiome during disease suppression. This illustrates how the host plant relies on the rhizosphere microbiome as the first line of defense to fight soil-borne pathogens. Microbial taxa and functions identified here can be used in novel strategies to control soil-borne fungal pathogens.

Phytotherapy: knowledge, experience and prescription in oral healthcare. A cross-sectional survey of dental practitioners / Conhecimento, experiência e prescrição de fitoterapia em saúde bucal: Um levantamento transversal com dentistas clínicos

ABSTRACT Herbal medicine is widely used as an integrative complementary treatment for common chronic diseases, yet potential risks include adverse effects and coprescription Aim This exploratory survey assessed Brazilian dentists' knowledge, attitudes, and practices regarding phytotherapy Material and Method This study used a consecutive sample of registered dentists who were active in clinical practice and attending advanced training for complex oral rehabilitation at a leading dental school in Latin America. Participants responded to a semi-structured 38-item instrument designed to collect data on sociodemographic, professional and health variables, and on their knowledge, use, prescription and opinions of phytotherapy. Quantitative data were analyzed with descriptive and inferential statistics. Qualitative data were described and analyzed with a thematic approach Results A total 53 dentists responded the survey (88.3% response rate). Six dentists reported formal education in phytotherapy and 33 had informal knowledge. Twenty-one dentists (39.6%) reported using herbal medicine, and 17 (32.1%) prescribed phytotherapy to their patients, mostly traditional medicinal plants. A logistic regression model showed that post-graduate degree and personal use of phytotherapy were associated with phytotherapy prescription. Opinions on how to improve the rational use of phytotherapy included the need for research evidence, specific academic education, and knowledge dissemination to clinicians. As a clinical recommendation, it was proposed that questions on herbal medicine should be asked during the dental patient's anamnesis Conclusions Dentists with post-graduate degrees and personal use of phytotherapy prescribe herbal medicines for their patients in real-world clinics, regardless of formal education on the subject. Qualitative findings indicate the need to implement scientific initiatives.

RESUMO A fitoterapia é amplamente utilizada como um tratamento integrativo e complementar para doenças crônicas comuns, mas os riscos potenciais incluem efeitos adversos e co-prescrição Objetivo Esta pesquisa exploratória avaliou o conhecimento, as atitudes e as práticas de cirurgiões-dentistas brasileiros sobre fitoterapia Materiais e Método Uma amostra consecutiva foi composta por dentistas com registro profissional, que eram ativos em prática clínica e frequentavam treinamento avançado para reabilitação oral complexa em uma das principais escolas de odontologia da América Latina. Os participantes responderam a um instrumento semiestruturado de 38 itens para coletar dados sobre variáveis sociodemográficas, profissionais e de saúde, bem como conhecimento, uso, prescrição e opiniões sobre fitoterapia. Os dados quantitativos foram analisados com estatística descritiva e inferencial. Os dados qualitativos foram descritos e analisados com abordagem temática Resultados Um total de 53 dentistas respondeu à pesquisa (taxa de resposta de 88,3%). Seis cirurgiões-dentistas relataram formação em fitoterapia e 33 possuíam conhecimento informal. Vinte e um dentistas (39,6%) relataram o uso de fitoterápicos e 17 (32,1%) prescreveram fitoterapia para seus pacientes, principalmente plantas medicinais tradicionais. Um modelo de regressão logística mostrou que pós-graduação e uso pessoal de fitoterapia estiveram associados à prescrição de fitoterapia. As opiniões para melhorar o uso racional da fitoterapia incluíram a necessidade de evidências de pesquisa, formação acadêmica específica e disseminação do conhecimento para os clínicos. Como recomendação clínica, foram propostas questões sobre fitoterapia para a anamnese odontológica do paciente Conclusões Cirurgiões-dentistas com pós-graduação e uso pessoal de fitoterapia prescrevem mais medicamentos fitoterápicos para seus pacientes em clínicas do mundo real, independentemente da educação formal sobre o assunto. Os resultados qualitativos indicam a necessidade de iniciativas de implementação científica.

Draft genome sequences of representative Paenibacillus polymyxa, Bacillus cereus, Fictibacillus sp., and Brevibacillus agri strains isolated from Amazonian dark earth.

Here, we report 10 distinct bacterial genomes from Amazonian dark earths, including six identified as Paenibacillus polymyxa, while the remaining four were unique representatives of Paenibacillus vini, Bacillus cereus, Brevibacillus agri, and Fictibacillus sp., respectively. Each strain exhibited antagonistic activity against Fusarium oxysporum, underscoring their potential as sustainable agriculture resources.

Soil and foliar Si fertilization alters elemental stoichiometry and increases yield of sugarcane cultivars.

Silicon (Si) fertilization is widely recognized to improve the development of crops, especially in tropical soils and cultivation under dryland management. Herein, our working hypothesis was that Si stoichiometry favors the efficient use of carbon (C), nitrogen (N), and phosphorus (P) in sugarcane plants. Therefore, a field experiment was carried out using a 3 × 3 factorial scheme consisting of three cultivars (RB92579, RB021754 and RB036066) and three forms of Si application (control without Si; sodium silicate spray at 40 mmol L-1 in soil during planting; sodium silicate spray at 40 mmol L-1 on leaves at 75 days after emergence). All Si fertilizations altered the elemental C and P stoichiometry and sugarcane yield, but silicon-induced responses varied depending on sugarcane cultivar and application method. The most prominent impacts were found in the leaf Si-sprayed RB92579 cultivar, with a significant increase of 7.0% (11 Mg ha-1) in stalk yield, 9.0% (12 Mg ha-1) in total recoverable sugar, and 20% (4 Mg ha-1) in sugar yield compared to the Si-without control. In conclusion, our findings clearly show that silicon soil and foliar fertilization alter C:N:P stoichiometry by enhancing the efficiency of carbon and phosphorus utilization, leading to improved sugarcane production and industrial quality.

Impact of the fungal pathogen Fusarium oxysporum on the taxonomic and functional diversity of the common bean root microbiome.

BACKGROUND: Plants rely on their root microbiome as the first line of defense against soil-borne fungal pathogens. The abundance and activities of beneficial root microbial taxa at the time prior to and during fungal infection are key to their protective success. If and how invading fungal root pathogens can disrupt microbiome assembly and gene expression is still largely unknown. Here, we investigated the impact of the fungal pathogen Fusarium oxysporum (fox) on the assembly of rhizosphere and endosphere microbiomes of a fox-susceptible and fox-resistant common bean cultivar. RESULTS: Integration of 16S-amplicon, shotgun metagenome as well as metatranscriptome sequencing with community ecology analysis showed that fox infections significantly changed the composition and gene expression of the root microbiome in a cultivar-dependent manner. More specifically, fox infection led to increased microbial diversity, network complexity, and a higher proportion of the genera Flavobacterium, Bacillus, and Dyadobacter in the rhizosphere of the fox-resistant cultivar compared to the fox-susceptible cultivar. In the endosphere, root infection also led to changes in community assembly, with a higher abundance of the genera Sinorhizobium and Ensifer in the fox-resistant cultivar. Metagenome and metatranscriptome analyses further revealed the enrichment of terpene biosynthesis genes with a potential role in pathogen suppression in the fox-resistant cultivar upon fungal pathogen invasion. CONCLUSION: Collectively, these results revealed a cultivar-dependent enrichment of specific bacterial genera and the activation of putative disease-suppressive functions in the rhizosphere and endosphere microbiome of common bean under siege.

Responses of a 6LiI Bonner Sphere Spectrometer using the Monte Carlo codes PHITS and MCNPX.

The response functions (RFs) of a Bonner Sphere Spectrometer (BSS) with a 6LiI thermal neutron detector were calculated using the Monte Carlo codes PHITS (version 3.26) and MCNPX (version 2.7.0), with their own default nuclear data libraries, and physics models. RFs were compared with other published data, obtained for the same spectrometer using the MCNP6.1 code with its own physics models. A discussion on the influence of using different nuclear data libraries and physics models using these codes/versions is analyzed.

Linking above and belowground carbon sequestration, soil organic matter properties, and soil health in Brazilian Atlantic Forest restoration.

Forest restoration mitigates climate change by removing CO2 and storing C in terrestrial ecosystems. However, incomplete information on C storage in restored tropical forests often fails to capture the ecosystem's holistic C dynamics. This study provides an integrated assessment of C storage in above to belowground subsystems, its consequences for greenhouse gas (GHG) fluxes, and the quantity, quality, and origin of soil organic matter (SOM) in restored Atlantic forests in Brazil. Relations between SOM properties and soil health indicators were also explored. We examined two restorations using tree planting ('active restoration'): an 8-year-old forest with green manure and native trees planted in two rounds, and a 15-year-old forest with native-planted trees in one round without green manure. Restorations were compared to reformed pasture and primary forest sites. We measured C storage in soil layers (0-10, 10-20, and 20-30 cm), litter, and plants. GHG emissions were assessed using CH4 and CO2 fluxes. SOM quantity was evaluated using C and N, quality using humification index (HLIFS), and origin using δ13C and δ15N. Nine soil health indicators were interrelated with SOM attributes. The primary forest presented the highest C stocks (107.7 Mg C ha-1), followed by 15- and 8-year-old restorations and pasture with 69.8, 55.5, and 41.8 Mg C ha-1, respectively. Soil C stocks from restorations and pasture were 20% lower than primary forest. However, 8- and 15-year-old restorations stored 12.3 and 28.3 Mg ha-1 more aboveground C than pasture. The younger forest had δ13C and δ15N values of 2.1 and 1.7‰, respectively, lower than the 15-year-old forest, indicating more C derived from C3 plants and biological N fixation. Both restorations and pasture had at least 34% higher HLIFS in deeper soil layers (10-30 cm) than primary forest, indicating a lack of labile SOM. Native and 15-year-old forests exhibited higher soil methane influx (141.1 and 61.9 µg m-2 h-1). Forests outperformed pasture in most soil health indicators, with 69% of their variance explained by SOM properties. However, SOM quantity and quality regeneration in both restorations approached the pristine forest state only in the top 10 cm layer, while deeper soil retained agricultural degradation legacies. In conclusion, active restoration of the Atlantic Forest is a superior approach compared to pasture reform for GHG mitigation. Nonetheless, the development of restoration techniques to facilitate labile C input into deeper soil layers (>10 cm) is needed to further improve soil multifunctionality and long-term C storage.

Exploring the diversity and composition of soil microbial communities in different soybean-maize management systems.

Soybean-maize are cultivated in different management systems, such as no-tillage and pastures, which presents potential to add organic residues, and it can potentially impacts the soil microbial community present in these systems. Thus, this study aimed to examine the effects of different soybean-maize management practices on the diversity and composition of soil microbial communities. Specifically, 16 S rRNA amplicon sequencing was used to investigate whether the use of pasture species in a fallowing system influences microbial communities in a soybean-maize rotation system, as compared to conventional tillage and no-tillage systems. The results indicate that the inclusion of the pasture species Urochloa brizantha in soybean-maize management systems leads to distinct responses within the soil microbial community. It was found that different soybean-maize management systems, particularly those with U. brizantha, affected the microbial community, likely due to the management applied to this pasture species. The system with 3 years of fallowing before soybean-maize showed the lowest microbial richness (∼2000 operational taxonomic units) and diversity index (∼6.0). Proteobacteria (∼30%), Acidobacteria (∼15%), and Verrucomicrobia (∼10%) were found to be the most abundant phyla in the soil under tropical native vegetation, while soils under cropland had an increased abundance of Firmicutes (∼30% to ∼50%) and Actinobacteria (∼30% to ∼35%). To summarize, this study identified the impacts of various soybean-maize management practices on the soil microbial community and emphasized the advantages of adding U. brizantha as a fallow species.

Interkingdom interaction: the soil isopod Porcellio scaber stimulates the methane-driven bacterial and fungal interaction.

Porcellio scaber (woodlice) are (sub-)surface-dwelling isopods, widely recognized as "soil bioengineers", modifying the edaphic properties of their habitat, and affecting carbon and nitrogen mineralization that leads to greenhouse gas emissions. Yet, the impact of soil isopods on methane-cycling processes remains unknown. Using P. scaber as a model macroinvertebrate in a microcosm study, we determined how the isopod influences methane uptake and the associated interaction network in an agricultural soil. Stable isotope probing (SIP) with 13C-methane was combined to a co-occurrence network analysis to directly link activity to the methane-oxidizing community (bacteria and fungus) involved in the trophic interaction. Compared to microcosms without the isopod, P. scaber significantly induced methane uptake, associated to a more complex bacteria-bacteria and bacteria-fungi interaction, and modified the soil nutritional status. Interestingly, 13C was transferred via the methanotrophs into the fungi, concomitant to significantly higher fungal abundance in the P. scaber-impacted soil, indicating that the fungal community utilized methane-derived substrates in the food web along with bacteria. Taken together, results showed the relevance of P. scaber in modulating methanotrophic activity with implications for bacteria-fungus interaction.