The impact of carbon source on cell growth and the production of bioactive compounds in cell suspensions of Hancornia speciosa Gomes.

Belonging to the Brazilian flora, the species Hancornia speciosa (Gomes), known as mangabeira, has bioactive compounds of interest, such as flavonoids, xanthones, and proanthocyanidins. The objective of this study was to determine how the supplementation of sugars in culture medium affects the osmotic potential of the medium, as well as its influence on cell growth and on the concentration of phenolic compounds. For this purpose, after 90 days of subculture, 20 mL aliquots of the cultures were added to flasks containing 20 mL of medium with different sugars (glucose, fructose, sucrose, mannitol, and sorbitol) under a 16-h photoperiod with a spectral range between 400 and 700 nm of photosynthetically active radiation (45-55 µmol m-2 s-1) in a shaker at 110 rpm. After 30 days, the pH, electrical conductivity, osmotic potential, biomass accumulation, and concentrations of phenolic compounds were evaluated. Regardless of their concentration in the medium, the sugars sorbitol and mannitol provided more unfavorable conditions for water absorption at the cellular level, reducing the water potential of the medium. Sucrose favored greater water absorption and biomass accumulation. Among the various sugar concentrations, 3% (30 g/L) sucrose or glucose improved the accumulation of fresh and dry cell weight and the production of polyphenols such as chlorogenic acid, epicatechin, rosmarinic acid, hesperidin, rutin, and quercetin. In addition, they resulted in a higher osmotic potential of the medium and larger cells than other carbon sources. Despite the differences in cell size, no culture conditions compromised cell survival.

Multifunctional potential of endophytic bacteria from Anacardium othonianum Rizzini in promoting in vitro and ex vitro plant growth.

Anacardium othonianum Rizzini, a cashew tree native to the Brazilian Cerrado, is economically important due to its applications in the food, chemical and pharmaceutical industries. However, A. othonianum yields a crop with low productivity due to a number of factors, such as nutritionally poor soils, drought and losses due to pests and diseases. Brazil is one of the nine largest cashew nut producers worldwide, and sustainable technologies are needed to increase the productivity of this crop. In this context, the use of endophytic microorganisms could promote plant growth and provide protection against phytopathogens. In this study, the isolation of the root endophytic community of A. othonianum led to the characterization of 22 distinct bacterial strains with multifunctional traits for plant growth promotion. The results of in vitro assays to assess auxin synthesis, phosphate solubilization, phosphatase and siderophore production and biocontrol against Fusarium oxysporum led to the selection of Acinetobacter lwoffii Bac109 and Pantoea agglomerans Bac131 as the most promising strains. The reinoculation of the Bac109 and Bac131 strains onto A. othonianum seeds showed that the treatment containing a mixture of these strains was the most effective in promoting increases in the biometric parameters of early plant growth. Thus, this study highlights the biotechnological potential of a consortium of A. lwoffii Bac109 and P. agglomerans Bac131 for future applications in sustainable cashew cultivation.

Selection of microorganisms and preparation of inoculants with potential applications in the remediation of soil contaminated with hexazinone / Seleção de microrganismos e preparo de inoculantes com potencial de aplicação na remediação de solo contaminado com hexazinona

The excessive use of agrochemicals negatively impacts the environment, making the development of sustainable technologies for the reduction of contaminants in soil necessary. Hexazinone is the herbicide most used for sugarcane crops and persists in the environment. Moreover, its main route of degradation in the soil is through microorganisms. Therefore, six microorganisms were selected that presented growth in the presence of the herbicide; SCR1 - Microbacterium arborescens; SCR2 - Bacillus pumilus; SCM3 - Stenotrophomonas maltophilia; SCM4 - Bacillus cereus; SCM5A - M. arborescens; and SCM5B - B. safensis. A test was performed to evaluate the ability of each lineage in phosphate solubilization. For the Ca3(PO4)2 solubilization test, the strains that showed the best results were B. pumilus and S. maltophilia. Subsequently, the inoculants were prepared and the concentrations after plating were 2.71 × 109 CFU mL-1 for B. pumilus, 1.02 × 109 CFU mL-1 for S. maltophilia, and 1.14 × 1010 CFU mL-1 for a combination of the two strains. These were satisfactory values for use as inoculants.(AU)

O uso de agroquímicos resulta em impactos ambientais e torna-se necessário o emprego de tecnologias sustentáveis para diminuição de contaminantes no solo. O hexazinona é o herbicida mais utilizado para a cultura da cana-de-açúcar, e apresenta persistência no ambiente. A principal via de degradação no solo é por meio de microrganismos. Com isso, selecionou-se seis microrganismos que apresentaram crescimento na presença do herbicida: SCR1 - Microbacterium arborescens; SCR2 - Bacillus pumilus; SCM3 - Stenotrophomonas maltophilia; SCM4 - Bacillus cereus; SCM5A - M. arborescens; SCM5B - Bacillus safensis. Foi realizado um teste para avaliar a habilidade de cada linhagem na solubilização de fosfatos, e no caso da solubilização de Ca3(PO4)2, as linhagens que apresentaram melhores resultados foram B. pumilus e S. maltophilia. Posteriormente, os inoculantes foram preparados e a concentração após plaqueamento de 2,71x109 UFC mL-1 para B. pumilus, 1,02x109 UFC mL-1 para S. maltophilia e consórcio com as duas linhagens 1,14x1010 UFC mL-1 apresentaram valores satisfatórios para utilização como inoculantes.(AU)