Endophytic fungi as robust biocatalysts to oxyfunctionalize hydro-carbon terpenes

CECATI FRANCISCO M.; KURINA-SANZ, MARCELA

Paris

Conferencia; Biotech Francia 2018; 2018

SETCOR

Biogenic volatile organic compounds (BVOCs)are industrially relevant biomaterials. Some ofthem, as limonene or pinene, are importantplatform chemicals. In the last decades, old andnew technologies have been optimized for theirextraction from agro-industrial wastes andabundant natural feedstokes. Synthetic biologyprovide other attractive alternatives to produceseveral mono- and sesquiterpenes byfermentation mediated by metabolicallyengineered microbes. More recently, elegant cell-free biochemistry platforms are emergingpromising to significantly increase the titres of afew C10H16 olefin hydrocarbons since overwhelmthe cell toxicity problems.1 The selectiveoxyfunctionalization of hydrocarbon BVOCscorrelates with the increase of their qualities asflavours, fragrances and bioactivity as well aswith the expansion of their uses as buildingblocks. Since redox reactions are involvedrequiring a high degree of specificity, whole cellbiotransformations are good alternatives.However they have the disadvantage that thesesubstrates are naturally antimicrobial. Ourhypothesis is that endophytic microorganismspossess the ability to survive in the presence ofBVOCs produced by the host plants of whichthey come from, because they have developedmetabolic skills to biotransform antimicrobialcomponents. In the present work we recoveredendophytes from a South American endemicplant, Eupatorium buniifolium, that produce amonoterpene enriched essential oil (EO). Threefungal strains showed the ability to tolerate, andtherefore biotransform, both the EO and four ofits main pure components R-(+)-limonene, α-(-)-pinene, α-(+)-pinene and sabinene. The strainswere characterized as Fusarium solani Eb01,Alternaria alternata Eb03 and Neofusicoccumsp. Eb04 by genomic and proteomic methods.Using these biocatalysts as resting cell, weaccessed to three new complex volatile matrixeswith different aroma notes from the original EO.Moreover, the bases of a couple ofbiotechnological processes to obtainenantiomerically pure terpinen-4-ol andlimonene-1,2-diol were set up using differentsources of pinene and limonene as substrates,respectively. This work shows that certainendophytic microorganisms are suitable toenlarge the tool-box for the generation ofvaluable bioproducts from hydrocarbon BVOCsdue to their robustness and biocatalytic skills.