Sex pheromone biosynthesis in the sugarcane borer Diatraea saccharalis: paving the way for biotechnological production.

BACKGROUND: The sugarcane borer Diatraea saccharalis (Lepidoptera) is a key pest on sugarcane and other grasses in the Americas. Biological control as well as insecticide treatments are used for pest management, but economic losses are still significant. The use of female sex pheromones for mating disruption or mass trapping in pest management could be established for this species, provided that economical production of pheromone is available. RESULTS: Combining in vivo labelling studies, differential expression analysis of transcriptome data and functional characterisation of insect genes in a yeast expression system, we reveal the biosynthetic pathway and identify the desaturase and reductase enzymes involved in the biosynthesis of the main pheromone component (9Z,11E)-hexadecadienal, and minor components hexadecanal, (9Z)-hexadecenal and (11Z)-hexadecenal. We next demonstrate heterologous production of the corresponding alcohols of the pheromone components, by expressing multiple steps of the biosynthetic pathway in yeast. CONCLUSION: Elucidation of the genetic basis of sex pheromone biosynthesis in D. saccharalis, and heterologous expression in yeast, paves the way for biotechnological production of the pheromone compounds needed for pheromone-based pest management of this species. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Production of moth sex pheromones for pest control by yeast fermentation.

The use of insect sex pheromones is an alternative technology for pest control in agriculture and forestry, which, in contrast to insecticides, does not have adverse effects on human health or environment and is efficient also against insecticide-resistant insect populations. Due to the high cost of chemically synthesized pheromones, mating disruption applications are currently primarily targeting higher value crops, such as fruits. Here we demonstrate a biotechnological method for the production of (Z)-hexadec-11-en-1-ol and (Z)-tetradec-9-en-1-ol, using engineered yeast cell factories. These unsaturated fatty alcohols are pheromone components or the immediate precursors of pheromone components of several economically important moth pests. Biosynthetic pathways towards several pheromones or their precursors were reconstructed in the oleaginous yeast Yarrowia lipolytica, which was further metabolically engineered for improved pheromone biosynthesis by decreasing fatty alcohol degradation and downregulating storage lipid accumulation. The sex pheromone of the cotton bollworm Helicoverpa armigera was produced by oxidation of fermented fatty alcohols into corresponding aldehydes. The resulting yeast-derived pheromone was just as efficient and specific for trapping of H. armigera male moths in cotton fields in Greece as a conventionally produced synthetic pheromone mixture. We further demonstrated the production of (Z)-tetradec-9-en-1-yl acetate, the main pheromone component of the fall armyworm Spodoptera frugiperda. Taken together our work describes a biotech platform for the production of commercially relevant titres of moth pheromones for pest control via yeast fermentation.

A single-host fermentation process for the production of flavor lactones from non-hydroxylated fatty acids.

Lactone flavors with fruity, milky, coconut, and other aromas are widely used in the food and fragrance industries. Lactones are produced by chemical synthesis or by biotransformation of plant-sourced hydroxy fatty acids. We established a novel method to produce flavor lactones from abundant non-hydroxylated fatty acids using yeast cell factories. Oleaginous yeast Yarrowia lipolytica was engineered to perform hydroxylation of fatty acids and chain-shortening via ß-oxidation to preferentially twelve or ten carbons. The strains could produce γ-dodecalactone from oleic acid and δ-decalactone from linoleic acid. Through metabolic engineering, the titer was improved 4-fold, and the final strain produced 282 mg/L γ-dodecalactone in a fed-batch bioreactor. The study paves the way for the production of lactones by fermentation of abundant fatty feedstocks.