Elucidation and engineering of Sphingolipid biosynthesis pathway in Yarrowia lipolytica for enhanced production of human-type sphingoid bases and glucosylceramides.

Sphingolipids are vital membrane components in in mammalian cells, plants, and various microbes. We aimed to explore and exploit the sphingolipid biosynthesis pathways in an oleaginous and dimorphic yeast Yarrowia lipolytica by constructing and characterizing mutant strains with specific gene deletions and integrating exogenous genes to enhance the production of long-chain bases (LCBs) and glucosylceramides (GlcCers). To block the fungal/plant-specific phytosphingosine (PHS) pathway, we deleted the SUR2 gene encoding a sphinganine C4-hydroxylase, resulting in a remarkably elevated secretory production of dihydrosphingosine (DHS) and sphingosine (So) without acetylation.

Isoprene production by Escherichia coli through the exogenous mevalonate pathway with reduced formation of fermentation byproducts.

Background: Isoprene, a volatile C5 hydrocarbon, is an important platform chemical used in the manufacturing of synthetic rubber for tires and various other applications, such as elastomers and adhesives.

Results: In this study, Escherichia coli MG1655 harboring Populus trichocarpa isoprene synthase (PtispS) and the exogenous mevalonate (MVA) pathway produced 80 mg/L isoprene. Codon optimization and optimal expression of the ispS gene via adjustment of the RBS strength and inducer concentration increased isoprene production to 199 and 337 mg/L, respectively.