Abstract: To characterizeSut2gene inPichiapastoriswhich can be induced by methanol, the function ofSut2and its relationship with methanol metabolism was studied. By homologous recombination,Sut2was deficientor overexpressed inPichiapastoris. Then, GS115-ΔSut2, GS115-Sut2and GS115 wild-type strains were cultured, and the transcription and translation levels ofAox1were detec-ted and compared. To identify the inducer ofSut2, methanol or formaldehyde was used as the sole carbon source for culturingPichiapastoris, and the transcription levels ofSut2were compared. High performance liquid chromatography (HPLC) was used to detect in-tracellular and extracellular ergosterol content of the three strains, GS115-ΔSut2, GS115-Sut2and GS115 wild-type. The results showed thatSut2was mainly induced by methanol, andSut2had a certain degree of positive regulation on the expression ofAox1with indirect interaction, which might be involved in complex regulatory networks and feedback loops. It was inferred thatSut2was involved in methanol metabolism by participating in sterol biosynthesis based on the HPLC results. This study would explore the regulatory mechanism ofSut2on methanol metabolism and further enrich the methanol metabolism pathway inPichiapastoris.

Key words: Pichiapastoris;Sut2;Aox1, methanol metabolism, ergosterol