Research abstract

Nature Biotechnology 10, 292 - 296 (1992)

Production of Active Bacillus licheniformis Alpha-Amylase in Tobacco and its Application in Starch Liquefaction

Jan Pen1, ,*, Lucy Molendijk1, Wim J. Quax2, Peter C. Sijmons1, Albert J. J. van Ooyen2, Peter J. M. van den Elzen1, Krijn Rietveld2 & André Hoekema1

As a first example of the feasibility of producing industrial bulk enzymes in plants, we have expressed Bacillus licheniformis alpha-amylase in transgenic tobacco, and applied the seeds directly in starch liquification. The enzyme was properly secreted into the intercellular space, and maximum expression levels of about 0.3% of total soluble protein were obtained. No apparent effect of the presence of the enzyme on plant phenotype was observed. The molecular weight of the enzyme produced in tobacco was around 64 kD. The difference, compared to 55.2 kD for the bacterial enzyme, was found to result from complex-type carbohydrate chains attached to the protein. Application studies on the liquefaction of starch were done with transgenic seeds containing the re-combinant alpha-amylase. The resulting hydrolysis products were virtually identical with those obtained from degradation with alpha-amylase from Bacillus licheniformis.

  1. 1MOGEN N.V., Einsteinweg 97, 2333 CB Leiden, The Netherlands.
  2. 2Gist-brocades N.V., Research and Development, P.O. Box 1, 2600 MA Delft, The Netherlands.
  3. *Corresponding author.