Subcellular engineering of lipase dependent pathways directed towards lipid related organelles for highly effectively compartmentalized biosynthesis of triacylglycerol derived products in Yarrowia lipolytica

Abstract

As an alternative to in vitro lipase dependent biotransformation and to traditional assembly of pathways in cytoplasm, the present study focused on targeting lipase dependent pathways to a subcellular compartment lipid body (LB), in combination with compartmentalization of associated pathways in other lipid relevant organelles including endoplasmic reticulum (ER) and peroxisome for efficient in vivo biosynthesis of fatty acid methyl esters (FAMEs) and hydrocarbons, in the context of improving Yarrowia lipolytica lipid pool. Through knock in and knock out of key genes involved in triacylglycerols (TAGs) biosynthesis and degradation, the TAGs content was increased to 51.5%, from 7.2% in parent strain. Targeting lipase dependent pathway to LB gave a 10-fold higher FAMEs titer (1028.0 mg/L) compared to cytosolic pathway (102.8 mg/L). Furthermore, simultaneously targeting lipase dependent pathway to LB, ER and peroxisome gave rise to the highest FAMEs titer (1644.8 mg/L). The subcellular compartment engineering strategy was extended to other lipase dependent pathways for fatty alkene and alkane biosynthesis, which resulted in a 14-fold titer enhancement compared to traditional cytosolic pathways. We developed yeast subcellular cell factories by directing lipase dependent pathways towards the TAGs storage organelle LB for efficient biosynthesis of TAG derived chemicals for the first time. The successful exploration of targeting metabolic pathways towards LB centered organelles is expected to promote subcellular compartment engineering for other lipid derived product biosynthesis.

Keywords: Biosynthesis; Lipase; Lipid body; Organelle; Subcellular compartment.