Production of functionalized oligo-isoprenoids by enzymatic cleavage of rubber.

In this study, we show the proof of concept for the production of defined oligo-isoprenoids with terminal functional groups that can be used as starting materials for various purposes including the synthesis of isoprenoid-based plastics. To this end, we used three types of rubber oxygenases for the enzymatic cleavage of rubber [poly(cis-1,4-isoprene)]. Two enzymes, rubber oxygenase RoxA and rubber oxygenase RoxB , originate from Xanthomonas sp. 35Y; the third rubber oxygenase, latex-clearing protein (Lcp ), is derived from Gram-positive rubber degraders such as Streptomyces sp. K30. Emulsions of polyisoprene (latex) were treated with RoxA , RoxB , Lcp or with combinations of the three proteins. The cleavage products were purified by solvent extraction and FPLC separation. All products had the same general structure with terminal functions (CHO-CH - and -CH -COCH ) but differed in the number of intact isoprene units in between. The composition and m/z values of oligo-isoprenoid products were determined by HPLC-MS analysis. Our results provide a method for the preparation of reactive oligo-isoprenoids that can likely be used to convert polyisoprene latex or rubber waste materials into value-added molecules, biofuels, polyurethanes or other polymers.