Accumulation of squalene in filamentous fungi Trichoderma virensPS1-7 in the presence of butenafine hydrochloride, squalene epoxidase inhibitor: biosynthesis of 13C-enriched squalene

Squalene is a triterpenoid compound and widely used in various industries such as medicine and cosmetics due to its strong antioxidant and anticancer properties. The purpose of this study is to increase the accumulation of squalene in filamentous fungi using exogeneous butenafine hydrochloride, which is an inhibitor for squalene epoxidase. The detailed settings achieved that the filamentous fungi, Trichoderma virensPS1-7, produced squalene up to 429.93 ± 51.60 mg/L after culturing for 7 days in the medium consisting of potato infusion with glucose at pH 4.0, in the presence of 200 µmbutenafine. On the other hand, no squalene accumulation was observed without butenafine. This result indicated that squalene was biosynthesized in the filamentous fungi PS1-7, which can be used as a novel source of squalene. In addition, we successfully obtained highly 13C-enriched squalene by using [U-13C6]-glucose as a carbon source replacing normal glucose.Graphical AbstractSqualene can be accumulated on large scale by filamentous fungi Trichoderma virensPS1-7 with butenafine hydrochloride inhibiting the squalene epoxidase.