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Expression Systems

• --> B. licheniformis
• --> H. polymorpha
  • --> Introduction
  • --> Maximum Yield
  • --> System Versatility

Bacillus licheniformis:
The High Yield Expression System

 

Advantages of
    the Bacillus System:

• Short development time
• Ultra-high level of expression
• Industrially proven

Proteins
    Successfully Expressed:

• Heterologous Proteins
   
  • Interleukin-3EGF
  • Esterase from Pseudomonas
     
• Homologous Gene Expression
   
  • B. stearothermophilus xylanase
  • Naproxen esterase
  • Amylases
  • Various Proteases

 

The Organism

You may know that the gram-positive bacterium Bacillus licheniformis has been used for several decades for the industrial production of alpha-amylase and various proteases. It has been classified as GRAS (Generally Recognized As Safe) by the U.S. Food and Drug Administration for the production of alpha-amylase.

An exoprotease deficient B. licheniformis host strain has been specifically tailored for heterologous gene expression. It is asporogenous and gives high extracellular expression levels with minimal loss of product due to proteolytic cleavage subsequent to secretion. To obtain a more genetically stable system after transformation and to increase production levels, the alpha-amylase gene has also been removed.

The Vectors

Vectors for B. licheniformis include both integrating as well as autonomously replicating forms. The essential elements of these vectors are the strong promoter, efficient terminator, suitable signal sequence, and a selection marker. Extensive studies on plasmid stability have shown the vector to be recombinationally stable and segregationally stable during fermentation in the absence of selective pressure.

Fermentation and Downstream Processing

After supplying the gene to BTR, we will create the construct and optimize its expression. BTR has over 40 years of fermentation development experience, and its capabilities range from shake flasks to pilot-scale. (See our Services, Resources, and Process Development pages for details.) The secretion of desired product into the fermentation medium allows for fairly straightforward downstream processing, eliminating the need for cell disruption or chemical processing techniques. This makes recovery relatively efficient and cost effective.

For more details, contact Reinhardt Rosson at:

rrosson@biotechresources.com
Phone: 920-684-5518
Fax: 920-684-5519