Abstract: We describe a regulated antigen delivery system (RADS) that has (a) a vector that includes (1) a gene encoding a desired gene product operably linked to a control sequence, (2) an origin of replication conferring vector replication using DNA polymerase III, and (3) an origin of replication conferring vector replication using DNA polymerase I, where the second origin of replication is operably linked to a control sequence that is repressible by a repressor. The RADS microorganism also has a gene encoding a repressor, operably linked to an activatible control sequence. The RADS described provide high levels of the desired gene product after repression of the high copy number origin of replication is lifted. The RADS are particularly useful as live bacterial vaccines. Also described is a delayed RADS system, in which there is a delay before the high copy number origin is expressed after the repression is lifted. The delayed RADS is also particularly useful for live bacterial vaccines.

Abstract: A method of vaccinating poultry by spraying the poultry with an effective amount of a live avirulent derivative of an enteropathogenic enterobacteria is disclosed.

Abstract: The present invention relates to the use of alkanes for the contamination-free purification or separation of biopolymers.

Abstract: The present invention relates to the production of biomass for the isolation of ccc plasmid DNA comprising culturing a bacterial transformant in a bioreactor containing an antibiotic-free batch medium under batch-conditions and, at the end of the batch phase, feeding under feed-back conditions the portion of a feed-back medium after the rise of the concentration of dissolved oxigen above a threshold-set point. Said feed-back medium comprises besides a carbon source a magnesium salt, preferably in concentrations above 20 mM. Preferably, the bacterial transformant is harvested after the end of the culture and frozen or freeze-dried. Also preferred is that ccc plasmid DNA is, optionally directly, isolated after harvesting the bacteria.

Abstract: The invention relates to a device for processing, especially for filtering and removing, fluids and fluid remnants in a low-pressure chamber (1). The device comprises a vacuum pump (30) and a separator (16), whereby the low-pressure chamber is connected to the separator via a first line (10), and the low-pressure chamber is connected to the vacuum pump via a second line (20) so that the low-pressure chamber can be evacuated while bypassing the separator. The invention also relates to a low-pressure chamber for processing fluids which is equipped with a heating plate with holes for heating areas of the interior space of the low-pressure chamber.