New support for E.coli BL21 whole cells immobilization and its application to nucleoside biotransformation

LETICIA BENTANCOR, JORGE TRELLES, MARIANO GRASSELLI, ELIZABETH LEWKOWICZ, AND ADOLFO IRIBARREN

Villa Carlos Paz, Córdoba

Congreso; XXXVII Reunión anual SAIBBM; 2001

SAIBBM

Whole cells immobilized have been used as efficient biocatalyst in the production of many chemical and pharmaceutical compounds. Sugar and/or base modified nucleosides have been extensively employed in cancer and antiviral therapies and, more recently, as building blocks for antisense strategies. Traditionally, nucleosides are prepared by chemical methods that often involve difficult, inefficient and time-consuming multistage processes. Microbial preparations of both natural and unnatural nucleosides are an alternative methodology, which offer regio and stereoselectivity and simple experimental conditions. Recently, we have demonstrated the high efficiency of E. coli BL21, in the synthesis of several purine nucleosides. However, the potential main advantages claimed for the use of immobilized viable cells include the easy separation and reuse of the cells. Amine containing modified polyethylene macroporous sheets was used as a novel matrix. Assessment of activity, stability and re-use of the immobilized cells was carried out using the synthesis of adenosine as control reaction. The results showed that this biocatalyst maintained highest activity for more than 100 days at both 4 ºC and 37 ºC, while at 60 ºC the activity dropped off within 2 days. Due to the good reuse capacity, high productivity in the synthesis of nucleoside analogues is promising.