摘要

The following study depicts the development of a whole cell biocatalyst for the prenylation of indole derivatives. For this purpose the prenyltransferase FgaPT2 from Aspergillus fumigatus was displayed on the surface of Escherichia coli cells by using Autodisplay. The presence of the prenyltransferase in the outer membrane was detected by using SDS-PAGE and Western Blot after the proteins of the outer membrane were isolated. The orientation of the prenyltransferase towards the outside of the cells was investigated by accessibility testing with externally added proteases. The FgaPT2 whole cell biocatalyst converted up to 250 mu m of indole-3-propionic acid, approximately 25% of the substrate used in the assay (100 mu L sample, OD(578) = 40). Another indole substrate, L-beta-homotryptophan was also investigated and a conversion of 13% was determined. By optimizing the assay conditions the conversion rate could be raised to approximately 30% of indole-3-propionic acid during a 24 h incubation time at 20 degrees C. The whole cell biocatalyst endured a storage period of one month at 8 degrees C without any detectable loss in activity. Reusability was confirmed by recycling the biocatalyst. After three cycles of consecutive use, the whole cell biocatalyst retained a conversion rate of 46% of indole-3-propionic acid and 23% of L-beta-homotryptophan after the third cycle.

  • 出版日期2011-7