Abstract: In order to explore aroma-producing bacterial resources from fermented grains of strong flavor Baijiu in Songhe town, the pure culture method combined with sensory evaluation was used to separate one bacterial strain with aroma-producing ability from fermented grains at different fermentation stages. The strain was identified as Cellulosimicrobium cellulans by morphological characteristics and phylogenetic analysis based on 16S rRNA gene, which was first isolated from fermented grains of Baijiu. It was found that the strain had cellulase and amylase activities under liquid-state culture conditions and had protease activity under acidic, neutral or alkaline conditions. It could withstand 9% ethanol concentration. Starch was used as carbon source to conduct fermentation under aerobic or facultative anaerobic conditions, and the flavor substances produced by this strain were detected by gas chromatography-mass spectrometry (GC-MS). The volatile substances in the fermentation broth under anaerobic conditions were mainly ethanol and acetic acid, whereas the compounds produced under aerobic conditions had complex structures, most of which were unknown.

Key words: strong flavor Baijiu; fermented grains; aroma-producing bacteria; isolation; identification