41 research outputs found
Bioactive Secondary Metabolites from a New Terrestrial Streptomyces sp. TN262
During our search for Streptomyces spp. as new producers of bioactive secondary metabolites, the ethyl acetate extract of the new terrestrial Streptomyces isolate TN262 delivered eight antimicrobially active compounds. They were identified as 1-acetyl-β-carboline (1), tryptophol (2), cineromycin B (3), 2,3-dihydrocineromycin B (4), cyclo-(tyrosylprolyl) (5), 3-(hydroxyacetyl)-indole (6), brevianamide F (7), and cis-cyclo-(l-prolyl-l-leucyl) (8). Three further metabolites were detected in the unpolar fractions using GC–MS and tentatively assigned as benzophenone (9), N-butyl-benzenesulfonamide (10), and hexanedioic acid-bis-(2-ethylhexyl) ester (11). This last compound is known as plasticizer derivatives, but it has never been described from natural sources. In this article, we describe the identification of the new Streptomyces sp. isolate TN262 using its cultural characteristics, the nucleotide sequence of the corresponding 16S rRNA gene and the phylogenetic analysis, followed by optimization, large-scale fermentation, isolation of the bioactive constituents, and determination of their structures. The biological activity of compounds (2), (3), (4), and those of the unpolar fractions was addressed as well
An overview of the recent developments on fructooligosaccharide production and applications
Over the past years, many researchers have suggested
that deficiencies in the diet can lead to disease states
and that some diseases can be avoided through an adequate
intake of relevant dietary components. Recently, a great interest
in dietary modulation of the human gut has been registered.
Prebiotics, such as fructooligosaccharides (FOS), play a key
role in the improvement of gut microbiota balance and in
individual health. FOS are generally used as components of
functional foods, are generally regarded as safe (generally
recognized as safe status—from the Food and Drug Administration,
USA), and worth about 150€ per kilogram. Due to
their nutrition- and health-relevant properties, such as moderate
sweetness, low carcinogenicity, low calorimetric value,
and low glycemic index, FOS have been increasingly used
by the food industry. Conventionally, FOS are produced
through a two-stage process that requires an enzyme production
and purification step in order to proceed with the chemical
reaction itself. Several studies have been conducted on the
production of FOS, aiming its optimization toward the development
of more efficient production processes and their potential
as food ingredients. The improvement of FOS yield and
productivity can be achieved by the use of different fermentative
methods and different microbial sources of FOS producing
enzymes and the optimization of nutritional and
culture parameter; therefore, this review focuses on the latest
progresses in FOS research such as its production, functional
properties, and market data.Agencia de Inovacao (AdI)-Project BIOLIFE reference PRIME 03/347. Ana Dominguez acknowledges Fundacao para a Ciencia e a Tecnologia, Portugal, for her PhD grant reference SFRH/BD/23083/2005
Study of Coffee Grounds Oil Action in PVC Matrix Exposed to Gamma Radiation: Comparison of Systems in Film and Specimen Forms
The effect of homogenisation and storage on the near-infrared spectra of half shell Pacific Oysters (Crassostrea gigas)
The effect of sample homogenisation and storage on the near-infrared spectra of Pacific Oysters (Crassostrea gigas) has been assessed. On each day of storage (Days 0, 3 and 5), spectra were collected using a Fourier transform near-infrared reflectance spectrometer in reflectance mode between 833 and 2,630 nm from whole (n = 20) and homogenised oysters (n = 20). The raw spectra were dominated by water- and fatty-acid-associated bands. Linear regression analysis of the water-associated absorbance bands occurring at 1,942 nm indicated that a physical or chemical interaction may be taking place within the oysters at or near Day 3, likely associated with transfer of liquids to and from oyster tissues. One-way analysis of variance of principal component scores and extended multiplicative scatter correction highlighted the water regions (O-H bonds) in whole oysters and the importance of N-H-related compounds in homogenised oysters throughout storage. These findings indicate the potential usefulness of near-infrared reflectance spectroscopy to monitor and evaluate degradation of oysters over time. © 2011 Springer Science+Business Media, LLC.Thomas Madigan, Andreas Kiermeier, Miguel de Barros Lopes, Daniel Cozzolin