Phosphorus (P) is one of the essential macronutrients for plant growth, being a highly required resource to improve the productive performance of several crops, especially in highly weathered soils. ...However, a large part of the nutrients applied in the form of fertilizers becomes “inert” in the medium term and cannot be assimilated by plants. Rationalizing the use of phosphorus is a matter of extreme importance for environmental sustainability and socioeconomic development. Therefore, alternatives to the management of this nutrient are needed, and the use of P-solubilizing microorganisms is an option to optimize its use by crops, allowing the exploration of less available fractions of the nutrient in soils and reducing the demand for phosphate fertilizers. The objective of this study is to discuss the importance of phosphorus and how microorganisms can intermediate its sustainable use in agriculture. In this review study, we present several studies about the role of microorganisms as phosphorus mobilizers in the soil. We describe the importance of the nutrient for the plants and the main problems related to the unsustainable exploitation of its natural reserves and the use of chemical fertilizers. Mainly we highlight how microorganisms constitute a fundamental resource for the release of the inert portion of the nutrient, where we describe several mechanisms of solubilization and mineralization. We also discussed the benefits that the inoculation of P-solubilizing microorganisms provides to crops as well as practices of using them as bioinoculants. The use of microorganisms as inoculants is a viable resource for the future of sustainable agriculture, mainly because its application can significantly reduce the application of P and, consequently, reduce the exploitation of phosphorus and its reserves. In addition, new research must be conducted for the development of new technologies, prospecting new biological products, and improvement of management practices that allow for higher efficiency in the use of phosphorus in agriculture.
Agriculture is a fundamental activity for human development. However, its sustainable practice is required to ensure the perpetuity of future resources. In this way, bacteria can benefit crops by ...making available nutrients and metabolites, mainly contributing to reducing the demand for chemical fertilizers. This study aimed to evaluate the biofertilizing capacity of Azospirillum brasilense, Bacillus megaterium, and Brevibacillus fluminis and their effects on improving the physiological and morphoanatomical properties of strawberry seedlings. In vitro tests were performed to evince their potential to supply nutrients (P and K) and produce siderophores and indole-acetic acid. In an inoculation experiment, these strains were inoculated in isolation and mixed in pairs and triples. This experiment was carried out in a greenhouse in a completely randomized design (CRD). The inoculated treatments were fertilized with 30% N and P demands; the uninoculated control received 30% and 100% of these demands. Leaf gas exchange, total chlorophylls, and crown diameter were evaluated during cultivation. After 138 days, leaf number, nutrient content, root length, root and shoot fresh and dry weight, and total seedlings were evaluated. The bacteria tested positive in all in vitro evaluations except for siderophore production. The strawberry responded positively to inoculation. The inoculation, either in isolation or in a mixture, improved stomatal conductance, leaf transpiration, internal CO2 concentration, leaf N and Mg contents, crown diameter, leaf area, and root elongation. We can conclude that the intermediation of microorganisms improves nutrient use efficiency and reduces the strawberry’s fertilizer demand by up to 70%, leading to plant development and yields comparable to complete fertilization.
Os efeitos dos sais nos solos, causando variações na estrutura, permeabilidade e aeração do solo, afetam indiretamente o crescimento das plantas. Desta forma o incremento da dosagem de nitrogênio, ...como fator isolado, pode promover melhor eficiência na produção de mudas. Neste sentido, objetivou-se com este trabalho, analisar a influência da salinidade da água de irrigação associada a doses crescentes de nitrogênio sobre o desenvolvimento de porta-enxerto de goiabeira de genótipo ‘Crioula’. O experimento foi conduzido em tubetes sob condições de ambiente protegido no CCTA/UFCG. Utilizou-se o delineamento experimental em blocos casualizados, com os tratamentos dispostos em esquema fatorial 5 x 4, correspondentes a cinco níveis de condutividade elétrica da água – CEa (0,3; 1,1; 1,9; 2,7 e 3,5 dS m-1) e quatro doses de nitrogênio (70, 100, 130 e 160% de N da dose recomendada para cultivo de mudas de goiabeira cv. Paluma) com 4 repetições e 5 plantas por parcela. Não houve interação significativa entre os fatores salinidade da água de irrigação e adubação nitrogenada sob o crescimento de porta-enxerto de goiabeira de genótipo “Crioula”. O aumento da CEa a partir de 0,3 dS m-1 afeta negativamente e de forma linear o diâmetro do caule (DC), número de folhas (NF), taxa de crescimento absoluto (TCAap) e relativo da altura de planta (TCRap), o equilíbrio de crescimento altura de planta/ diâmetro do caule e a exportação de massa seca da folha para o resto da planta (RMF). A dose de 70% de N (541,1 mg de N dm-1 de solo) proporciona maiores valores do DC, NF, TCAap e TCRap de porta-enxerto de goiabeira “Crioula”.
A escassez de água de boa qualidade e a ocorrência de solos com baixa fertilidade são fatores limitantes para a agricultura irrigada, principalmente em regiões áridas e semiáridas, o que induz a ...utilização de águas salinas e adubação nitrogenada como alternativas para a produção agrícola nessas regiões. Desta forma, objetivou-se avaliar a influência de doses de nitrogênio no crescimento de mudas de goiabeira cv. Paluma irrigadas com águas de diferentes salinidades. Utilizou-se o delineamento experimental de blocos casualizados, em esquema fatorial 5 x 4, com 4 repetições, relativos aos cinco níveis de condutividade elétrica da água – CEa (0,3; 1,1; 1,9; 2,7 e 3,5 dS m-1) e quatro doses de nitrogênio (70, 100, 130 e 160% de N), sendo a dose padrão 100% N igual a 773mg de N dm-3. A formação de fitomassa de porta-enxerto de cajueiro é reduzido pelo aumento da CEa da água de irrigação, no entanto, a irrigação com água de CEa 2,15 dS m-1 promove reduções aceitáveis de 15%. A utilização da adubação com 541,1 mg de N dm-3 de solo (equivalente a 70% da dose recomendada) proporciona o maior crescimento para o porta-enxerto de goiabeira cv. Paluma. Houve interação entre os fatores em estudo para variável diâmetro do caule.
Eight molecules, four peptides (SPs) and four lipopeptides (LPs) derived by rational design from surfactin, a well‐known secreted biosurfactant from Bacillus subtilis, were produced employing ...Fmoc‐based solid‐phase synthesis. These new peptides were tested to evaluate their potential biosurfactant and biological activities, aiming at possible applications in industrial, biological, pharmaceutical, and medical use. Five molecules (SP1, SP2, SP4, LP5, and LP8) presented potential for medical uses, mainly due to their drug delivery properties as suggested by their synergistic activity with the antibiotic vancomycin against Staphylococcus aureus. All synthetic peptides showed low toxicity against Vero cell cultures, in assays of hemolysis, and in different cytotoxicity assays. In addition, we found that three peptides (SP1, LP6, and LP7) had potential technological and industrial use because of their emulsifying capacity, low toxicity, and ability to physically stabilize solutions. These novel molecules retained some properties of the parental molecule (surfactin, which was originally obtained through nonribosomal synthesis in Bacillus subtilis) but have the advantage of being linear peptides, which can be produced at large scales through the use of conventional heterologous protein expression protocols.
We synthesized eight novel linear peptides derived from surfactin using classical Fmoc‐based solid‐phase synthesis method for their production. All of the peptides had surface tension reduction activity, and several of them facilitated the delivery of the antibiotic vancomycin, exhibiting synergism with its action against a virulent strain of S aureus (MU50). Cytotoxicity was evaluated through different assays; the promising results indicated that all of the peptides were poorly cytotoxic and that only one (LP8) had considerable hemolytic activity.
Methicillin-resistant Staphylococcus aureus (MRSA) is one of the main pathogens that cause infections in diabetic individuals. In this paper, we report the outcomes of our investigation on the ...intradermal application of antimicrobial photodynamic therapy (PDT) with curcumin in an infection induced by MRSA ATCC 43300 strain in the ear of mice with Type 1 Diabetes Mellitus (T1DM). A solution containing 100 μg of curcumin was photoactivated ex vivo with a LED light (450 nm) delivering a fluency of 13.5 J/cm3. This solution was administered in the ear intradermally, at the same inoculum site as the MRSA ATCC 43300 strain (PDT Group). This study also included the use of two control groups (both infected): One was treated with saline and the other was treated with non-photoactivated curcumin. The animals were euthanized 24 h after these treatments and samples of draining lymph node and treated ear were collected for examination. The PDT group showed lower bacterial load in the draining lymph node when compared to the saline and curcumin groups (p-value <0.05) 24 h after treatment. In addition to bacterial load, the PDT group presented a higher concentration of nitrates and nitrites in the draining lymph node when compared to the saline and curcumin groups (p-value <0.001). Examining the infectious site, despite apparently having similar inflammatory cell recruitment compared with the control groups, the PDT group showed a profile with less intense activity in the myeloperoxidase expression when compared to the saline group (p-value <0.001). Additionally, the detected concentration of cytokines such as IL-1β, IL-12, and IL-10 was significantly lower in the PDT group when compared to the saline group (p-value <0.01; p-value <0.05; p-value <0.05, respectively), thus presenting a less intense inflammatory response during infection resolution. Our pilot study showed for the first time the therapeutic potential of PDT using curcumin when administered intradermally in the treatment of infections caused by S. aureus in mice with T1DM.
•PDT acts to control bacterial load in infected mice with type 1 diabetes.•PDT using curcumin has therapeutic effect when used to control bacterial load in vivo.•The expression of inflammatory markers can be modulated by PDT.•Free radicals production is increased in diabetic organisms when treated with PDT.
Chagas disease, caused by the Trypanosoma cruzi, has a wide distribution in South America, and its main method of control is the elimination of triatomines. It is presented here the geographic ...distribution and the rate of natural infection by T. cruzi of triatomines collected and evaluated from 2008 to 2013 in southwest of Bahia. Triatomines were captured in the intradomiciliary and peridomiciliary areas of five cities located in the southwest of Bahia state, identified, and analyzed for the presence of trypanosomatids in their feces. During the study period the number of patients suspected for acute Chagas disease was recovered from the Notifiable Diseases Information System (SINAN). 8966 triatomines were captured and identified as belonging to eight species. Twenty-six presented themselves infected, being Triatoma sordida the most abundant and with the highest percentage of infection by T. cruzi. Tremedal was the city with the highest number of cases of acute Chagas' disease reported to SINAN. All cities showed triatomines infected with T. cruzi, so there is considerable risk of vectorial transmission of Chagas disease in the southwestern Bahia state, evidencing the need for vector transmission control programs and preventive surveillance measures.
The spectrum of clinical presentation of Fabry disease (FD) in women is broad and challenging. The aim is to evaluate the effectiveness of an alternative screening method for FD in women.
A ...collaborative multicenter cross-sectional study to evaluate the sensitivity and specificity of the combination of two tests (α-GAL enzyme activity assay and lyso-GL3 assay) for the diagnosis of FD in women. We included women with chronic kidney disease (CKD) stages 3 to 5, receiving conservative treatment or on dialysis programs, from different nephrology services in Brazil.
We evaluated 1874 patients that underwent blood collection for α-GAL and lyso-GL3 assays. Isolated decreased α-GAL enzyme activity was found in 64 patients (3.5%), while isolated increased lyso-GL3 levels were found in 67 patients (3.6%), with one patient presenting alterations in both tests. All cases with low α-GAL enzyme activity and/or increased lyso-GL3 levels underwent genetic analysis for FD variants (132 performed GLA genetic test). Low α-GAL enzyme activity had higher sensitivity and specificity to detect FD compared to the other measures (elevated lyso-GL3 alone or both altered). The negative predictive value (NPV) of α-GAL activity was 99%, and the positive predictive value (PPV) was 9.2%. For lyso-GL3 assay, the specificity was 99.7% and the PPV was 2.9%, therefore considered inferior to α-GAL assay. Both assays altered, had higher PPV (100%) and higher NPV (99.7%) considered the best method. We found 7 cases of GLA gene variants found, resulting in an initial prevalence of 0.37% for FD in this sample female population.
This study contributes to the diagnostic value of the biomarkers α-GAL and lyso-GL3 in the context of FD in women with CKD. The combination of these biomarkers was an effective approach for the diagnosis of the disease, with high PPV and NPV.
Translocation of rare populations is regarded as the last resort for the conservation of species whose habitat destruction is imminent. The objective of the present study was to evaluate the effect ...of two height classes and three leaf reduction intensities on growth and increases in height, stem diameter, survival, and new leaf production in seedlings of Aspidosperma cylindrocarpon (peroba) obtained via rescue seedlings in a remnant of tropical semi deciduous forest. We recovered 240 individuals that were divided into two height classes (Class I-5 to 15cm and Class II-20 to 35cm) and subjected to three leaf reduction intensities (0%, 50%, and 100%), which were then transported to a shade house with 50% light reduction. Measurements of height, stem diameter, and new leaf production were collected 8 times at 0, 15, 60, 75, 90, 105, 120, and 135 days, and survival rate was measured at day 135. The average survival rate was 82.9%; 77.5% for one Class I (5-15cm) and 88.3% for Class II (20-35cm). Higher seedling growth was observed for the 0% leaf reduction treatment in both height classes. The leaves insertion were greater in the 100% cuts, with a decrease observed over time. It is advisable to restore A. cylindrocarpon seedlings in two height classes owing to the high survival rate, leaf appearance, and growth reported in the present study. The no-leaf reduction treatment (0%) is the most viable alternative for the production of A. cylindrocarpon seedlings, via rescue seedlings.
RESUMO: As translocações de populações raras são consideradas como o último recurso para conservação de espécies, cuja destruição do habitat é iminente. O objetivo deste trabalho foi avaliar o efeito de duas classes de altura e três intensidades de redução foliar no crescimento, incremento periódico, sobrevivência e inserção de folhas em mudas de Aspidosperma cylindrocarpon (peroba) obtidas via resgate de plântulas em um remanescente de Floresta Estacional Semidecídua. Foram resgatados 240 indivíduos, os quais foram divididos em duas classes de altura (Classe I-5 a 15cm e Classe II-20 a 35cm), submetidos a três intensidades de redução foliar (0%, 50% e 100%) e em seguida, transportados para casa de sombra com 50% de redução de luminosidade. As medições de altura, diâmetro e emissão de novas folhas foram realizadas em oito tempos (0, 15, 60, 75, 90, 105, 120 e 135 dias), e a sobrevivência aos 135 dias. A taxa média de sobrevivência foi de 82,9%, sendo 77,5% para a classe de 5-15cm e 88,3% para classe de 20-35cm. O maior crescimento das mudas ocorreu para a redução de 0%, para ambas as classes. A inserção de folhas foi maior nas reduções de 100%, observando-se diminuição ao longo do tempo. Portanto, é aconselhável resgatar mudas de peroba nas duas classes de altura, sem necessidade de redução foliar.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
PDF
