Self-powered infusion microfluidic pump for ex vivo drug delivery.

In this work, we present a new iSIMPLE concept (infusion Self-powered Imbibing Microfluidic Pump by Liquid Encapsulation), which requires no external power for activation nor liquid manipulation, it is easy to use while its fabrication method is extremely simple, inexpensive and suited for mass replication. The pump consists of a working liquid, which is - after finger activation - absorbed in a porous material (e.g.

Biocatalysis on the surface of Escherichia coli: melanin pigmentation of the cell exterior.

Today, it is considered state-of-the-art to engineer living organisms for various biotechnology applications. Even though this has led to numerous scientific breakthroughs, the enclosed interior of bacterial cells still restricts interactions with enzymes, pathways and products due to the mass-transfer barrier formed by the cell envelope. To promote accessibility, we propose engineering of biocatalytic reactions and subsequent product deposition directly on the bacterial surface.

Metabolic engineering of Escherichia coli for enhanced arginine biosynthesis.

Background: Arginine is a high-value product, especially for the pharmaceutical industry. Growing demand for environmental-friendly and traceable products have stressed the need for microbial production of this amino acid. Therefore, the aim of this study was to improve arginine production in Escherichia coli by metabolic engineering and to establish a fermentation process in 1-L bioreactor scale to evaluate the different mutants.

Cultivation strategies for production of (R)-3-hydroxybutyric acid from simultaneous consumption of glucose, xylose and arabinose by Escherichia coli.

Background: Lignocellulosic waste is a desirable biomass for use in second generation biorefineries. Up to 40% of its sugar content consist of pentoses, which organisms either take up sequentially after glucose depletion, or not at all. A previously described Escherichia coli strain, PPA652ara, capable of simultaneous consumption of glucose, xylose and arabinose was in the present work utilized for production of (R)-3-hydroxybutyric acid (3HB) from a mixture of glucose, xylose and arabinose.

Mutations in 16S rRNA that suppress cold-sensitive initiation factor 1 affect ribosomal subunit association.

A mutation in the infA gene encoding initiation factor 1 (IF1) gives rise to a cold-sensitive phenotype. An Escherichia coli strain with this mutation was used as a tool to select for second-site suppressors that compensate for the cold sensitivity and map specifically to rRNA. Several suppressor mutants with altered 16S rRNA that partially restore growth of an IF1 mutant strain in the cold were isolated and characterized.

Suppression of a cold-sensitive mutant initiation factor 1 by alterations in the 23S rRNA maturation region.

Genetic selection has been used to isolate second-site suppressors of a defective cold-sensitive initiation factor I (IF1) R69L mutant of Escherichia coli. The suppressor mutants specifically map to a single rRNA operon on a plasmid in a strain with all chromosomal rRNA operons deleted. Here, we describe a set of suppressor mutations that are located in the processing stem of precursor 23S rRNA.