4 research outputs found
Robust estimation of bacterial cell count from optical density
Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data
Green tea, white tea, and Pelargonium purpureum increase the antioxidant capacity of plasma and some organs in mice
Bioactive fatty acids in seafood from Ionian Sea and relation to dietary recommendations
Nanotechnology Applications to Improve Solubility of Bioactive Constituents of Foods for Health-Promoting Purposes
Foods-derived multifunctional compounds, such as carotenoids, vitamins, phytosterols, polyunsaturated lipids, curcuminoids, flavonoids and polyphenols, in addition to the basic nutritional value, own extra health benefits and are considered \u201cpharmaceutical-grade nutrients\u201d better known as \u201dnutraceuticals\u201d. Similarly, phytochemicals from plants, characterized by analogous chemical structures, can be considered \u201cpharmaceutical-grade molecules\u201d. They could provide both diseases preventive actions and remarkable therapeutic benefits but, the efforts for identifying their mode of action and for applying them into food industry with health-promoting purposes, are often unsuccessful. Solubility is essential for a good absorption in the gastrointestinal tract and to achieve the systemic concentration necessary for an effective therapeutic activity, but the majority of these compounds are water-insoluble. Consequently, when ingested, they encounter many difficulties in crossing the diverse barriers to reach the bloodstream and to distribute to cells and tissues. Their absorption at gastric or intestinal level is troubled and in addition, they suffer from early degradation or fast metabolism, so rarely they manage to reach the site of action in therapeutically effective concentration and their clinical applications result strongly limited. Toxic excipients and harmful solubilizing agents were and are extensively used for solubilizing and delivering non-soluble bioactive chemicals (BACs) despite the resulting unpleasant side effects complained of by patients. During last decades, several new techniques, often resorting to nanotechnology, aiming at enhancing BACs solubility, at solving their pharmacokinetics drawbacks, at avoiding their early inactivation or fast metabolism, have been developed. On this background, the following chapter provides an overview concerning nanotechnology contribute and its technological advancements in \u201cmanufacturing\u201d nutraceuticals and phytochemicals in more bioavailable nanoparticles. In addition, it is reviewed the involvement of nanoscience in developing and enhancing food-grade solid nanosized materials to be used as BACs \u201ccontainers\u201d and \u201cvehicles\u201d either for their safe and effective oral administration, in the frame of medical treatments, or for achieving smart food ingredients to improve the quality and shelf life of nourishments