Characterization and evaluation of potential halotolerant phosphate solubilizing bacteria from Salicornia fruticosa rhizosphere.

Soil salinization is a significant abiotic factor threatening agricultural production, while the low availability of phosphorus (P) in plants is another worldwide limitation. Approximately 95-99% of the P in soil is unavailable to plants. Phosphate-solubilizing bacteria (PSB) transform insoluble phosphates into soluble forms that plants can utilize. The application of PSB can replace or partially reduce the use of P fertilizers. Therefore, selecting bacteria with high solubilization capacity from extreme environments, such as saline soils, becomes crucial. This study aimed to identify twenty-nine bacterial strains from the rhizosphere of Salicornia fruticosa by sequencing the 16S rDNA gene, evaluate their development in increasing concentrations of NaCl, classify them according to their salinity response, and determine their P solubilization capability. The bacteria were cultivated in nutrient agar medium with NaCl concentrations ranging from 0.5% to 30%. The phosphate solubilization capacity of the bacteria was evaluated in angar and broth National Botanical Research Institute (NBRIP) media supplemented with calcium phosphate (CaHPO4) and aluminum phosphate (AlPO4), and increased with 3% NaCl. All bacterial strains were classified as halotolerant and identified to the genera Bacillus, Enterobacter, Halomonas, Kushneria, Oceanobacillus, Pantoea, Pseudomonas, and Staphylococcus, with only one isolate was not identified. The isolates with the highest ability to solubilize phosphorus from CaHPO4 in the liquid medium were Kushneria sp. (SS102) and Enterobacter sp. (SS186), with 989.53 and 956.37 mg·Kg-1 P content and final pH of 4.1 and 3.9, respectively. For the solubilization of AlPO4, the most effective isolates were Bacillus sp. (SS89) and Oceanobacillus sp. (SS94), which raised soluble P by 61.10 and 45.82 mg·Kg-1 and final pH of 2.9 and 3.6, respectively. These bacteria demonstrated promising results in in vitro P solubilization and can present potential for the development of bioinput. Further analyses, involving different phosphate sources and the composition of produced organic acids, will be conducted to contribute to a comprehensive understanding of their applications in sustainable agriculture.

Caracterização química do óleo essencial de Hypericum brasiliense Choisy

Hypericum brasiliense Choisy, planta da família Guttiferae, ocorre principalmente nas regiões Sudeste e Sul do Brasil. Em trabalhos anteriores foram isolados e identificados nesta espécie, dentre outras classes de compostos, xantonas, floroglucinóis e flavonóides. Apesar da presença de óleos essenciais ser uma característica do gênero, ainda não há registros na literatura da composição química do óleo essencial desta espécie. Neste trabalho foi realizado o estudo químico da fração volátil de H. brasiliense visando identificar e quantificar as substâncias químicas presentes através da cromatografia em fase gasosa acoplada a espectrômetro de massas equipado com banco de dados.

Hypericum brasiliense Choisy, plant of the Guttiferae family, occurs mainly in the regions Southeastern and South of Brazil. Xanthones, phloroglucinols, flavonoids and other compounds were isolated from this species. There are not registrations in the literature of the chemical composition of the essential oil of this species, in spite of the importance of these compounds in the chemistry of the genera. In this work, it was done the chemical study of the volatile fraction obtained by hidrodestilation of H. brasiliense and this fraction was analyzed by CG/MS.

Otimização do processo de extração de própolis através da verificação da atividade antimicrobiana

A própolis, também conhecida como "cola de abelhas" possui atividade antimicrobiana, antiinflamatória, anestésica e imunoestimulante. Amostras de diferentes origens geográficas podem apresentar composição química bem diferente, porém continuam sendo responsáveis por atividade antibacteriana, inclusive contra cepas multirresistentes de Staphylococcus aureus. Este trabalho teve por objetivo otimizar o processo de extração visando determinar a melhor alcoolatura para a obtenção de tinturas de própolis com maior atividade antimicrobiana. Amostras de própolis foram extraídas com diferentes misturas hidroalcoólicas, variando o teor de etanol entre 90 por cento a água pura, obtendo assim 11 tinturas diferentes. Todas as tinturas foram aplicadas em discos de papel, secos e colocados sobre a superfície de placas contendo ágar inoculado com cepa multirresistente de S. aureus. As placas foram incubadas e avaliadas no dia seguinte quanto à presença de halos de inibição. Os melhores resultados foram obtidos com extratos contendo 50 a 90 por cento de etanol. O trabalho sugere a utilização da alcoolatura de 70 por cento como a ideal para a obtenção de tinturas de própolis.

Bee glue (propolis) possesses antimicrobial, antiinflammatory, anaesthetic and immunostimulating activities. Propolis composition is extraordinary variable; samples from different geographic origin may posse's entirely different chemical composition. In different propolis samples, various substance combinations are responsible for the antibacterial activity of the bee glue. The aim of the study was to evaluate the best ethanolic extract concentration using Staphylococcus aureus multiresistant. Ethanol extracts from different concentration (10 to 90 percent) were applied on paper disks, dried, and put on the surface of nutrient agar plates with the overlay containing S. aureus. The plates were then incubated and evaluated the next day for the presence of inhibition zones. The best result was verified among 60 to 90 percent of ethanolic extract of propolis. This paper suggests the use of the alcool 70 percent as the ideal for the extration of propolis.