Starmerella bombicola lactone esterase in Pichia pastoris through temperature adaptation, codon-optimization and co-expression with HAC1]]>

摘要

AbstractTheStarmerella bombicolalactone esterase (SBLE) is a novel enzyme that,in vivo, catalyzes the intramolecular esterification (lactonization) of acidic sophorolipids in an aqueous environment. In fact, this is an unusual reaction given the unfavorable conditions for dehydration. This characteristic strongly contributes to the potential of SBLE to become a 'green' tool in industrial applications. Indeed, lactonization occurs normally in organic solvents, an application for which microbial lipases are increasingly used as biocatalysts. Previously, we described the production of recombinant SBLE (rSBLE) inPichia pastoris(syn.Komagataella phaffii). However, expression was not optimal to delve deeper into the enzyme's potential for industrial application. In the current study, we explored codon-optimization of theSBLEgene and we optimized the rSBLE expression protocol. Temperature reduction had the biggest impact followed by codon-optimization and co-expression of theHAC1transcription factor. Combining these approaches, we achieved a 32-fold improvement of the yield during rSBLE production (from 0.75?mg/l to 24?mg/L culture) accompanied with a strong reduction of contaminants after affinity purification.Graphical abstract