Construction and Application of a Plasmid-Based Signal Peptide Library for Improved Secretion of Recombinant Proteins with .

The secretion of recombinant proteins plays an important role in their economic production and purification. The secretion efficiency depends on the responsible signal peptide (SP) in combination with the target protein and the given host and cannot be predicted so far. Due to its high plasmid stability, the lack of alkaline extracellular proteases and only few contaminating extracellular host proteins, provides a promising alternative to common species.

The "beauty in the beast"-the multiple uses of Priestia megaterium in biotechnology.

Over 30 years, the Gram-positive bacterium Priestia megaterium (previously known as Bacillus megaterium) was systematically developed for biotechnological applications ranging from the production of small molecules like vitamin B, over polymers like polyhydroxybutyrate (PHB) up to the in vivo and in vitro synthesis of multiple proteins and finally whole-cell applications. Here we describe the use of the natural vitamin B (cobalamin) producer P. megaterium for the elucidation of the biosynthetic pathway and the subsequent systematic knowledge-based development for production purposes.

Crystal structures and protein engineering of three different penicillin G acylases from Gram-positive bacteria with different thermostability.

Penicillin G acylase (PGA) catalyzes the hydrolysis of penicillin G to 6-aminopenicillanic acid and phenylacetic acid, which provides the precursor for most semisynthetic penicillins. Most applications rely on PGAs from Gram-negative bacteria. Here we describe the first three crystal structures for PGAs from Gram-positive Bacilli and their utilization in protein engineering experiments for the manipulation of their thermostability.

Human and animal isolates of Yersinia enterocolitica show significant serotype-specific colonization and host-specific immune defense properties.

Yersinia enterocolitica is a human pathogen that is ubiquitous in livestock, especially pigs. The bacteria are able to colonize the intestinal tract of a variety of mammalian hosts, but the severity of induced gut-associated diseases (yersiniosis) differs significantly between hosts. To gain more information about the individual virulence determinants that contribute to colonization and induction of immune responses in different hosts, we analyzed and compared the interactions of different human- and animal-derived isolates of serotypes O:3, O:5,27, O:8, and O:9 with murine, porcine, and human intestinal cells and macrophages.