First described over 100 years ago, B. megaterium has recently been gaining more and more importance in scientific as well as industrial applications. The source of its significant name "megaterium" is its large size of the vegetative cells (over 10 μm) and its spores. The capability of sporulation has made B. megaterium an important tool for examining spore-mediated disease and cell development.

B. megaterium is able to grow on a wide variety of carbon sources and thus has been found in many ecological niches such as waste from meat industry or petrochemical effluents. Also, the degradation of persistent insecticides by B. megaterium has been documented (Saxena et al., 1987; Selvanayagam and Vijaya, 1989) offering potential applications as detoxifying agent. One of the genetic regulatory elements for carbon utilization is the xylose operon. It has been described by Rygus and Hillen (1991) and is used in the expression system MoBiTec is offering in this kit.

Further, several B. megaterium proteins are of importance. For example, a family of P450 cytochrome monooxygenases is similar to eukaryotic P450 playing a role in many diseases. Industrial applications of enzymes excreted by B. megaterium are diverse, starting from amylases used in bread industry to penicillin amidase which is used for the generation of new synthetic antibiotics.

Advantages:

• B. megaterium is not pathogenic
• No endotoxins found in the cell wall
• Tightly regulated and efficiently inducible xylA operon (up to 350-fold)
• Stable, high yield protein production
• No indication of proteolytic instability even up to 5 h after induction, since alkaline proteases such as e.g. in B. subtilis are not produced
• Suited for small to industrial-scale protein production
• Plasmids available for either intra- or extracellular production of recombinant proteins
• Extended polylinker downstream of promoter allows versatile cloning
• Easy purification and detection of either 6xHis, Strep-tagged or Strep-/6xHis-double-tagged target proteins
• Removable purification tags due to TEV and Factor Xa protease cleavage sites
• Compatible with all Bacillus subtilis vectors
• Host strains MoBiTec offers have been found to be asporogenic on common media
• System might be suitable also for other Bacillus ssp.