Abstract: A thermophilic actinomycete strain, FBKL4.010, was successfully isolated from Moutai-flavor Daqu. Using morphological, physiological method, 16S rRNA genephylogenetic analysis and phylogenetic analysis, it was identified as Laceyella sacchari. Its optimum growth temperature was 45 ℃. According to the liquor-making system, pure-culture solid-state fermentation experiments were designed with strain FBKL4.010 and its flavor components were detected by solid-phase microextraction combined with gas chromatography-mass spectrometry (GC-MS). The results showed that this strain could produce a large number of pyrazine and aromatic substances with strong Douchi and nutty flavors in fermentation broth. Tetramethyl pyrazine, which was considered to be one of the main flavour components of Moutai-flavor liquor, accounted for 43.318% of total volatile components. This study is expected to lay a good foundation for further research on the relationship between this strain and the formation of Moutai flavour.

Key words: Moutai-flavour Daqu, Thermoactinomycetaceae, pyrazine, flavor components