The periplasmic space of Gram-negative bacteria such as Escherichia coli and Salmone~la typh~murium contains a large variety of proteins with a wide range of functions. These proteins are associated with nutrient metabolism, transport, chemotaxis, antibiotic resistance, and energy utilization. There are about a dozen or so periplasmic proteins that participate in transport of small polar substr...

Infectious Pancreatic Necrosis Virus (IPNV) is a member of the family Birnaviridae that has been linked to high mortalities in salmonids. Bacterial based systems as live vectors for the delivery of heterologous antigens offer a number of advantages as vaccination strategies. VP2 is a structural viral protein of IPNV with immunogenicity effects. In this study IPNV was isolated from diseased fry ...

Electron cryotomography was used to analyze the structure of the Lyme disease spirochete, Borrelia burgdorferi. This methodology offers a new means for studying the native architecture of bacteria by eliminating the chemical fixing, dehydration, and staining steps of conventional electron microscopy. Using electron cryotomography, we noted that membrane blebs formed at the ends of the cells. Th...

Gram-negative bacteria are surrounded by two membrane bilayers separated by a space termed the periplasm. The periplasm is a multipurpose compartment separate from the cytoplasm whose distinct reducing environment allows more efficient and diverse mechanisms of protein oxidation, folding, and quality control. The periplasm also contains structural elements and important environmental sensing mo...

The OMPs (outer membrane proteins) of Gram-negative bacteria have to be translocated through the periplasmic space before reaching their final destination. The aqueous environment of the periplasmic space and high permeability of the outer membrane engender such a translocation process inevitably challenging. In Escherichia coli, although SurA, Skp and DegP have been identified to function in t...

Spirochetes have a unique structure, and as a result their motility is different from that of other bacteria. They also have a special attribute: spirochetes can swim in a highly viscous, gel-like medium, such as that found in connective tissue, that inhibits the motility of most other bacteria. In spirochetes, the organelles for motility, the periplasmic flagella, reside inside the cell within...

Extracellular electron transfer is the key metabolic trait that enables some bacteria to play a significant role in the biogeochemical cycling of metals and in bioelectrochemical devices such as microbial fuel cells. In Shewanella oneidensis MR-1, electrons generated in the cytoplasm by catabolic processes must cross the periplasmic space to reach terminal oxidoreductases found at the cell surf...

The influence of different carbon and nitrogen sources on growth of recombinant Escherichia coli and human interferon-α2b (IFN-α2b) production in periplasmic space was studied in shake flask culture. A statistical method based on Plackett-Burman design was used to screen the main medium components that greatly influenced the performance of the fermentation process. The optimization of medium wa...

Periplasmic substrate binding proteins (PSBPs) are essential components of the bacterial periplasmic transport system, which transports a wide variety of nutrients from the periplasmic space to the cytoplasm. The glutamate/aspartate binding protein SfGlu/AspBP is a unique PSBP consisting of 279 amino acid residues. The SfGlu/AspBP gene was cloned, over-expressed, and purified by immobilized met...

We examine a general class of adaptive behavior models in which the distant past has only a weak effect on current actions, and assume that agents sometimes make mistakes, to show that average behavior (averaged over time) converges, with probability one, to a unique limit. Mistakes generate global convergence and are an equilibrium selection device; for small mistake probabilities the equilibr...