Endophytic fungi as robust biocatalysts to oxyfunctionalize hy-drocarbon terpenes

CECATI FM; KURINA SANZ M

Paris

Exposición; BiotechFrance2018; 2018

SETCOR

Abstract:Biogenic volatile organic compounds (BVOCs) are industrially relevant biomaterials. Some of them, as limonene or pinene, are important platform chemicals. In the last decades, old and new technologies have been optimized for their extraction from agro-industrial wastes and abundant natural feedstokes. Synthetic biology provide other attractive alternatives to produce several mono- and sesquiterpenes by fermentation mediated by metabolically engineered microbes. More recently, elegant cell-free biochemistry platforms are emerging promising to significantly increase the titres of a few C10H16 olefin hydrocarbons since overwhelm the cell toxicity problems.1 The selective oxyfunctionalization of hydrocarbon BVOCs correlates with the in-crease of their qualities as flavours, fragrances and bioactivity as well as with the expansion of their uses as building blocks. Since redox reactions are involved requiring a high degree of specificity, whole cell biotransformations are good alternatives. However they have the disadvantage that these substrates are naturally antimicrobial. Our hypothesis is that endophytic microorganisms possess the ability to survive in the presence of BVOCs produced by the host plants of which they come from, because they have developed metabolic skills to biotransform antimicrobial components. In the present work we recovered endophytes from a South American endemic plant, Eupatorium buniifolium, that produce a monoterpene enriched essential oil (EO). Three fungal strains showed the ability to tolerate, and therefore biotransform, both the EO and four of its main pure components R-(+)-limonene, α-(-)-pinene, α-(+)-pinene and sabinene. The strains were characterized as Fusarium solani Eb01, Alternaria alternata Eb03 and Neofusicoccum sp. Eb04 by genomic and proteomic methods. Using these biocatalysts as resting cell, we accessed to three new complex volatile matrixes with different aroma notes from the original EO. Moreover, the bases of a couple of biotechnological processes to obtain en-antiomerically pure terpinen-4-ol and limo-nene-1,2-diol were set up using different sources of pinene and limonene as substrates, respectively. This work shows that certain endophytic microorganisms are suitable to enlarge the tool-box for the generation of valuable bioproducts from hydrocarbon BVOCs due to their robustness and biocata-lytic skills. Keywords: biotransformation, endophytic fungi, monoterpenes, biooxidation, BVOCs.