Abstract: Acetaldehyde is a flavor substance in alcoholic beverages. Excessive acetaldehyde not only affects the flavor of alcoholic beverages，but also causes health damages to human body. This study is to screen edible probiotic strains with the ability to metabolize acetaldehyde，and explore the relationship between acetaldehyde metabolism and ethanol-induction. Strain HCCB 20591 of Lactobacillus rhamnosus with strong acetaldehyde metabolism ability was obtained via a resting cell system，and its metabolic ability was induced by ethanol. When the ethanol concentration was 3% and the induction time was 12 h，the acetaldehyde conversion ratio by HCCB 20591 was 41.13%. GC-MS analysis of the acetaldehyde metabolites showed that in addition to acetic acid，ethanol was also generated by HCCB 20591. RT-PCR method was used to analyze the transcription level of the related genes. It was found that acetaldehyde metabolism was the combined catalytic result of alcohol dehydrogenase，aldehyde dehydrogenase and aldehyde oxidoreductase.

Key words: Lactobacillus rhamnosus, ethanol-induction, acetaldehyde metabolism, combined catalytic result