large-insert-environmental-genomic-library-production

Large Insert Environmental Genomic Library Production

The vast majority of microbes in nature currently remain inaccessible to traditional cultivation methods. Over the past decade, culture-independent ...

expression-recombinant-proteins-methylotrophic-yeast-pichia

Expression of Recombinant Proteins in the Methylotrophic Yeast <em>Pichia pastoris</em>

Protein expression in the microbial eukaryotic host Pichia pastoris offers the possibility to generate high amounts of recombinant protein in a fast and ...

a-high-throughput-screen-for-biomining-cellulase-activity-from

A High Throughput Screen for Biomining Cellulase Activity from Metagenomic Libraries

Cellulose, the most abundant source of organic carbon on the planet, has wide-ranging industrial applications with increasing emphasis on biofuel ...

Wachstum, Virulenz und Immunogenit&#xE4;t von Listeria monocytogenes aro-Mutanten.

Mutants of Listeria monocytogenes with deletions in genes of the common branch of the biosynthesis pathway leading to aromatic compounds were constructed as possible virulence-attenuated carrier strains for protein antigens or vaccine DNA. aroA, aroB, and in particular aroE mutants showed strongly reduced growth rates in epithelial cells and even in rich culture media. The metabolism of the aro mutants under these conditions was predominantly anaerobic. Aerobic metabolism and a wild-type growth rate were, however, regained upon the addition of vitamin K2, suggesting that the aro mutants are deficient in oxidative respiration due to the lack of menaquinone. Replication of the aro mutants in the host cell's cytosol and cell-to-cell spread were drastically slowed down, and all aro mutants showed high virulence attenuation in mice, i.e., the 50% lethal dose in BALB/c mice was increased at least 10(4)-fold for the aroA, aroB, and aroA/B mutants and >10(5)-fold for the aroE mutant compared to the parent strain. Nevertheless, mice preimmunized with aro mutant bacteria elicited good T-cell response and full protection against a subsequent challenge with the virulent wild-type strain. A total of 5 x 10(6) aroA, aroB, and aroA/B mutant bacteria were sufficient to obtain a protective T-cell response, while 5 x 10(8) aroE or aroA/E mutants were necessary to achieve comparable numbers of antigen-specific T cells. These numbers were well tolerated without causing any signs of disease, indicating that Listeria strains with deletions in genes of the basic branch of the aromatic amino acid pathway could be useful vaccine carriers for inducing T-cell immunity.

Growth, virulence, and immunogenicity of Listeria monocytogenes aro mutants.

Soil samples were screened to select microorganisms with the capability to oxidize organic sulfides into the corresponding sulfoxides with differential enantioselectivities. Several bacterial strains that preferentially produced the S-configured sulfoxide enantiomer were isolated. Surprisingly, one bacterial strain, genotypically and phenotypically characterized as Pseudomonas frederiksbergensis, selectively gave the R enantiomer. The finding that two apparently identical organisms displayed opposite enantioselectivities is novel for non-genetically modified organisms.

Opposite enantioselectivities of two phenotypically and genotypically similar strains of Pseudomonas frederiksbergensis in bacterial whole-cell sulfoxidation.

Gegen&#xFC;ber Enantioselektivit&#xE4;ten von zwei ph&#xE4;notypisch und genotypisch &#xE4;hnlicher St&#xE4;mme von Pseudomonas frederiksbergensis in bakteriellen whole-cell Sulfoxidation.

Bacillus megaterium, isolated in a screening process from topsoil, was used for N-demethylation of natural N-methyl methyl anthranilate to produce natural methyl anthranilate. Maximal productivity of 70 mg/L/day was achieved under laboratory-scale conditions without further optimization. No byproducts were observed. Thus, production of "natural" methyl anthranilate using B. megaterium is a significant improvement over comparable already existing procedures.

Production of natural methyl anthranilate by microbial N-demethylation of N-methyl methyl anthranilate by the topsoil-isolated bacterium Bacillus megaterium.

Bacillus Megaterium, isoliert in einem Screening-Verfahren von Mutterboden, wurde f&uuml;r N-Demethylierung von nat&uuml;rlichen N-Methyl-Methyl-Anthranilat verwendet, um nat&uuml;rliche Methyl Anthranilat zu produzieren. Maximale Produktivit&auml;t von 70 mg/L/Tag wurde unter Laborma&szlig;stab Bedingungen ohne weitere Optimierung erreicht. Keine Nebenprodukte wurden beobachtet. So ist die Produktion von &quot;nat&uuml;rliche&quot; Methyl Anthranilat mit B. Megaterium eine signifikante Verbesserung &uuml;ber vergleichbare bereits bestehenden Verfahren.

Produktion von nat&uuml;rlichen Methyl Anthranilat durch mikrobielle N-Demethylierung von N-Methyl-Methyl-Anthranilat durch den Mutterboden-isolierte Bakterium Bacillus Megaterium.

Oxidative N-demethylation was measured by incubation experiments using Bacillus megaterium isolated from topsoil as a biocatalyst for the N-demethylation of the N,N-dialkylarylamines N,N-dimethylaniline and N-ethyl-N-methylaniline. Formed formaldehyde, normally difficult to analyse in biological systems because of further metabolization, was successfully trapped and converted into thiazolidine by addition of cysteamine into the incubation media. Studies using N,N-di-(trideutero-methyl)-aniline and N-ethyl-N-(trideuteromethyl)-aniline as well as N,N-di-[methyl-(13)C]-aniline and N-ethyl-N-[methyl-(13)C]-aniline were performed to confirm that the N-demethylation proceeds via formaldehyde.

Direct trapping of formaldehyde formed via oxidative N-demethylation of N,N-dialkylarylamines by Bacillus megaterium using cysteamine derivatization.

Oxidative N-Demethylierung wurde mittels Inkubation-Experimente, die mit Bacillus Megaterium isoliert von Mutterboden als ein Biokatalysator f&uuml;r den N-Demethylierung von N, N-Dialkylarylamines-N, N-Dimethylanilin und N-Ethyl-N-Methylaniline. Gebildete Formaldehyd, normalerweise schwierig, wegen weiterer Metabolization, in biologischen Systemen zu analysieren wurde erfolgreich gefangen und durch Zugabe von Cysteamin in die Inkubation-Medien in Thiazolidin umgewandelt. Studien mit N, N-di-(trideutero-methyl)-Anilin und N-Ethyl - N-(Trideuteromethyl) - Anilin wie N, N - di-[Methyl-(13) C] - Anilin und N-ethyl-N-[methyl-(13)C]-aniline wurden durchgef&uuml;hrt, um zu best&auml;tigen, dass die N-Demethylierung &uuml;ber Formaldehyd verl&auml;uft.

Direkte Trapping von Formaldehyd gebildet &uuml;ber oxidative N-Demethylierung von N, N-Dialkylarylamines von Bacillus Megaterium mit Cysteamin Derivatisierung.

Dieser Artikel beschreibt allgemeine Design-Prinzipien f&uuml;r funktionale Metagenomik. Der Schwerpunkt liegt auf Escherichia coli als Ausdruck Host, obwohl Alternativen Host-Vektor-Systeme in Bezug auf die Optimierung von Gen-Erholung in ma&szlig;nahmenbezogenen Bildschirme diskutiert werden. Beispiele f&uuml;r DNA Isolierung und Bereicherung Ans&auml;tze, Bibliotheksbau und ph&auml;notypische Auslesen werden mit besonderem Schwerpunkt auf die Verwendung von Hochdurchsatz-Technologien f&uuml;r die schnelle Isolierung Umwelt Klone Codierung ph&auml;notypische Merkmale von Interesse beschrieben.

Die Kunst und Design von funktionalen durchgef&uuml;hrte metagenomische Bildschirmen.

This article summarizes general design principles for functional metagenomics. The focus is on Escherichia coli as an expression host, although alternative host-vector systems are discussed in relation to optimizing gene recovery in activity-based screens. Examples of DNA isolation and enrichment approaches, library construction and phenotypic read-out are described with special emphasis on the use of high throughput technologies for rapid isolation of environmental clones encoding phenotypic traits of interest.

ArticleTotal : 3	Year
Publication title Cited by 18	2009
Publication title Cited by 58	2010
Publication title Cited by 24	2011

Article	Year
Growth, virulence, and immunogenicity of Listeria monocytogenes aro mutants. Infection and immunity\| PubMed ID: 15385459	2004
Opposite enantioselectivities of two phenotypically and genotypically similar strains of Pseudomonas frederiksbergensis in bacterial whole-cell sulfoxidation. Applied and environmental microbiology\| PubMed ID: 15812060	2005
Production of natural methyl anthranilate by microbial N-demethylation of N-methyl methyl anthranilate by the topsoil-isolated bacterium Bacillus megaterium. Journal of agricultural and food chemistry\| PubMed ID: 16302781	2005
Direct trapping of formaldehyde formed via oxidative N-demethylation of N,N-dialkylarylamines by Bacillus megaterium using cysteamine derivatization. Journal of microbiological methods\| PubMed ID: 16787677	2006
The art and design of functional metagenomic screens. Current opinion in biotechnology\| PubMed ID: 21440432	2011

Marcus Taupp

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