RESUMO
The effects of an enzymatic treatment with cellulase and mannanase on the properties of marine microalgae Nannochloropsis sp. were investigated. The combined use of these enzymes synergistically promoted the recovery of lipids from the microalgae, increasing the extraction yield from 40.8 to over 73%. Untreated and enzymatically treated microalgae were characterized by chemical analysis and by TGA/DTG, FTIR, XRD and SEM. Significant changes were observed in the chemical composition and thermal behavior of the microalgae. The enzymatic treatment also resulted in an increase of the crystalline-to-amorphous cellulose ratio. SEM images revealed dramatic changes in cell morphology, extensive cell damage and release of intracellular material. Overall, the results obtained indicate that the enzymes used are capable of disrupting the microalgal cell wall and that a combination of common analytical techniques can be used to assess the enzyme-induced damage.
Assuntos
Microalgas , beta-Manosidase , Celulase , Lipídeos , EstramenópilasRESUMO
Over the last two decades, ever increasing interest has been focused on π-conjugated triple-bond-containing systems, namely, (poly)aryl acetylenes, as a very promising class of semiconducting materials, owing to the availability of flexible/efficient synthetic protocols and the new conception of their conformational and steric advantages. In this review, the major design/synthetic strategies used to obtain molecular aryl acetylene semiconductors are discussed. A brief discussion of their key properties as well as their performance in organic field-effect transistors and photovoltaic cell applications is also included.
RESUMO
We evaluated the toxicity of graphite nanoplatelets (GNPs) in the model organism Caenorhabditis elegans. The GNPs resulted nontoxic by measuring longevity as well as reproductive capability end points. An imaging technique based on Fourier transform infrared spectroscopy (FT-IR) mapping was also developed to analyze the GNPs spatial distribution inside the nematodes. Conflicting reports on the in vitro antimicrobial properties of graphene-based nanomaterials prompted us to challenge the host-pathogen system C. elegans-Pseudomonas aeruginosa to assess these findings through an in vivo model.