Safety of Novel Microbes for Human Consumption: Practical Examples of Assessment in the European Union

Novel microbes are either newly isolated genera and species from natural sources or bacterial strains derived from existing bacteria. Novel microbes are gaining increasing attention for the general aims to preserve and modify foods and to modulate gut microbiota. The use of novel microbes to improve health outcomes is of particular interest because growing evidence points to the importance of gut microbiota in human health. As well, some recently isolated microorganisms have promise for use as probiotics, although in-depth assessment of their safety is necessary. Recent examples of microorganisms calling for more detailed evaluation include Bacteroides xylanisolvens, Akkermansia muciniphila, fructophilic lactic acid bacteria (FLAB), and Faecalibacterium prausnitzii. This paper discusses each candidate's safety evaluation for novel food or novel food ingredient approval according to European Union (EU) regulations. The factors evaluated include their beneficial properties, antibiotic resistance profiling, history of safe use (if available), publication of the genomic sequence, toxicological studies in agreement with novel food regulations, and the qualified presumptions of safety. Sufficient evidences have made possible to support and authorize the use of heat-inactivated B. xylanisolvens in the European Union. In the case of A. muciniphila, the discussion focuses on earlier safety studies and the strain's suitability. FLAB are also subjected to standard safety assessments, which, along with their proximity to lactic acid bacteria generally considered to be safe, may lead to novel food authorization in the future. Further research with F. prausnitzii will increase knowledge about its safety and probiotic properties and may lead to its future use as novel food. Upcoming changes in EUU Regulation 2015/2283 on novel food will facilitate the authorization of future novel products and might increase the presence of novel microbes in the food market

Fractal geometry of aggregate snowflakes revealed by triple wavelength radar measurements

Radar reflectivity measurements from three different wavelengths are used to retrieve information about the shape of aggregate snowflakes in deep stratiform ice clouds. Dual-wavelength ratios are calculated for different shape models and compared to observations at 3, 35 and 94 GHz. It is demonstrated that many scattering models, including spherical and spheroidal models, do not adequately describe the aggregate snowflakes that are observed. The observations are consistent with fractal aggregate geometries generated by a physically-based aggregation model. It is demonstrated that the fractal dimension of large aggregates can be inferred directly from the radar data. Fractal dimensions close to 2 are retrieved, consistent with previous theoretical models and in-situ observations

Effect of tamoxifen on hepatic regeneration in male rats

A number of metabolic changes within the liver occur concurrent with hepatic regeneration. These processes suggest that the administration of an antiestrogen might alter the rate of hepatic regeneration. To examine this question, male Wistar rats were treated with tamoxifen (0.1 mg/rat/day or 1.0 mg/rat/day) or vehicle for three days prior to and after partial hepatectomy, and the anatomic and biochemical process of hepatic regeneration was assessed. Tamoxifen administration caused a dose-dependent decrease in the hepatic cytosolic estrogen receptor activity and, conversely, a dose-dependent increase in cytosolic androgen receptor activity. Despite these changes in baseline hepatic sex steroid receptor status, all receptor activities were comparable between the three groups within 24 hr of partial hepatectomy. Moreover, no differences in any of the the parameters assessing hepatic regeneration following partial hepatectomy were evident: liver-body ratio, ornithine decarboxylase activity, and thymidine kinase activity. This lack of effect of tamoxifen treatment on hepatic regeneration suggests either that estrogens do not play a role in the modulation of liver growth after partial hepatectomy or that, once initiated, the regenerative process per se determines a series of events that regulate hepatocellular sex hormone receptor status independent of extrahepatic stimuli. © 1989 Plenum Publishing Corporation

PI3Kinase signaling in glioblastoma

Glioblastoma (GBM) is the most common primary tumor of the CNS in the adult. It is characterized by exponential growth and diffuse invasiveness. Among many different genetic alterations in GBM, e.g., mutations of PTEN, EGFR, p16/p19 and p53 and their impact on aberrant signaling have been thoroughly characterized. A major barrier to develop a common therapeutic strategy is founded on the fact that each tumor has its individual genetic fingerprint. Nonetheless, the PI3K pathway may represent a common therapeutic target to most GBM due to its central position in the signaling cascade affecting proliferation, apoptosis and migration. The read-out of blocking PI3K alone or in combination with other cancer pathways should mainly focus, besides the cytostatic effect, on cell death induction since sublethal damage may induce selection of more malignant clones. Targeting more than one pathway instead of a single agent approach may be more promising to kill GBM cells

Plant C-N-Hydrolases and the identification of a plant N-Carbamoylputrescine amidohydrolase involved in polyamine biosynthesis

A nitrilase-like protein from Arabidopsis thaliana (NLP1) was expressed in Escherichia coli as a His(6)-tagged protein and purified to apparent homogeneity by Ni(2+)-chelate affinity chromatography. The purified enzyme showed N-carbamoylputrescine amidohydrolase activity, an enzyme involved in the biosynthesis of polyamines in plants and bacteria. N-carbamoylputrescine amidohydrolase activity was confirmed by identification of two of the three occurring products, namely putrescine and ammonia. In contrast, no enzymatic activity could be detected when applying various compounds including nitriles, amines, and amides as well as other N-carbamoyl compounds, indicating the specificity of the enzyme for N-carbamoylputrescine. Like the homologous beta-alanine synthases, NLP1 showed positive cooperativity toward its substrate. The native enzyme had a molecular mass of 279 kDa as shown by blue-native polyacrylamide gel electrophoresis, indicating a complex of eight monomers. Expression of the NLP1 gene was found in all organs investigated, but it was not induced upon osmotic stress, which is known to induce biosynthesis of putrescine. This is the first report of cloning and expression of a plant N-carbamoylputrescine amidohydrolase and the first time that N-carbamoylputrescine amidohydrolase activity of a recombinant protein could be shown in vitro. NLP1 is one of the two missing links in the arginine decarboxylase pathway of putrescine biosynthesis in higher plants

PAN-Kapillarmembran

Polyacrylonitrile capillary membrane (PAN membrane), with an average pore size of less than 10 nm, a narrow pore size distribution characterised by sigma -values of less than 0.3, and a pore density of more than 109 pores/cm2 in the active separation layer. Also claimed is a process for the production of PAN capillary membrane with a comonomer content of less than 1 wt%. USE - Used as an osmosis membrane, especially in capillary osmometers (claimed). ADVANTAGE - An improved capillary membrane with a small pore size, a narrow pore size distribution and a high pore density, combined with good wettability and good stability in typical membrane osmometry solvents, e.g. water, ether, toluene, THF, dioxan, acetone, trichloroethylene

Evidence of nonspheroidal behavior in millimeter-wavelength radar observations of snowfall

Recent modeling results have indicated that, in general, idealized homogeneous spheroidal models of ice crystals and snowflakes cannot consistently describe radar backscattering from snowfall when the radar wavelengths are on the order of the snowflake size. In this paper, we provide empirical evidence supporting this prediction by analyzing collocated airborne radar measurements at 13.4 GHz, 35.6 GHz and 94 GHz. The analysis is performed by applying a recently developed method making use of two simultaneously measured dualq-frequency ratios, allowing one to distinguish between the multifrequency backscattering behavior of detailed aggregate snow models and that of homogeneous spheroids. We demonstrate that in some naturally occurring cases, detailed snowflake models, which account for their complex structure, are required to describe backscattering by these particles in a manner that is consistent over multiple wavelengths. This implies that the spheroidal approximation is not always adequate as a snowflake shape model in radar retrievals at this wavelength range