Methodological variations in the isolation of genomic DNA from Streptococcus bacteria

In this work, genomic DNA of Streptococcus pyogenes, S. mutans and S. sobrinus was isolated using two methods: either using the detergent cetyltrimethylammonium bromide (CTAB) at 65ºC; or by applying ultrasound to a mixture of silica and celite in CTAB. The composite method that used ultrasound was the more efficient, allowing the straightforward extraction of genomic DNA from Gram-positive bacteria with good quality and reproducibility.<br>O gênero Streptococcus encontra-se amplamente distribuído na natureza e algumas espécies constituem a microbiota humana da cavidade bucal, como Streptococcus pyogenes, que pode estar associado a importantes doenças humanas, Streptococcus mutans e Streptococcus sobrinus, relacionados à cárie dental. O DNA genômico destas três espécies foi isolado utilizando-se dois métodos, o primeiro utilizando o detergente brometo de cetiltrimetilamônio (CTAB) à 65ºC e outro associando ultra-som a uma mistura de sílica e celite em CTAB. O método que possibilitou a extração do DNA genômico das bactérias Gram positivas, com qualidade, boa reprodutibilidade fácil execução foi aquele que utilizou ultra-som associado à sílica e celite em CTAB

Designing food structure to control stability, digestion, release and absorption of lipophilic food components

The bioavailability of dietary lipophilic components may be either increased or decreased by manipulating the microstructure and/or physicochemical properties of the foods that contain them. This article stresses how knowledge of the molecular, physicochemical, and physiological processes that occur during lipid ingestion, digestion, and absorption can be used to rationally design food structures to control these processes and therefore impact the rate or extent of lipid digestion and/or absorption. These approaches include controlling the molecular characteristics of the lipid molecules, altering lipid droplet size or interfacial properties, and manipulating food matrix structure and composition. Improved knowledge of the molecular, physicochemical, and physiological processes that occur during lipid ingestion, digestion, and absorption will facilitate the rational design and fabrication of functional foods for improved health and wellness

The Ascomycota tree of life: A phylum-wide phylogeny clarifies the origin and evolution of fundamental reproductive and ecological traits

We present a 6-gene, 420-species maximum-likelihood phylogeny of Ascomycota, the largest phylum of Fungi. This analysis is the most taxonomically complete to date with species sampled from all 15 currently circumscribed classes. A number of superclass-level nodes that have previously evaded resolution and were unnamed in classifications of the Fungi are resolved for the first time. Based on the 6-gene phylogeny we conducted a phylogenetic informativeness analysis of all 6 genes and a series of ancestral character state reconstructions that focused on morphology of sporocarps, ascus dehiscence, and evolution of nutritional modes and ecologies. A gene-by-gene assessment of phylogenetic informativeness yielded higher levels of informativeness for protein genes (RPB1, RPB2, and TEF1) as compared with the ribosomal genes, which have been the standard bearer in fungal systematics. Our reconstruction of sporocarp characters is consistent with 2 origins for multicellular sexual reproductive structures in Ascomycota, once in the common ancestor of Pezizomycotina and once in the common ancestor of Neolectomycetes. This first report of dual origins of ascomycete sporocarps highlights the complicated nature of assessing homology of morphological traits across Fungi. Furthermore, ancestral reconstruction supports an open sporocarp with an exposed hymenium (apothecium) as the primitive morphology for Pezizomycotina with multiple derivations of the partially (perithecia) or completely enclosed (cleistothecia) sporocarps. Ascus dehiscence is most informative at the class level within Pezizomycotina with most superclass nodes reconstructed equivocally. Character-state reconstructions support a terrestrial, saprobic ecology as ancestral. In contrast to previous studies, these analyses support multiple origins of lichenization events with the loss of lichenization as less frequent and limited to terminal, closely related species