Abstract:

Oenococcus oeni (O. oeni) is considered as the key processer of malolactic fermentation (MLF), which will
influence wine quality. Indigenous microorganisms are increasingly considered as one of the factors influencing the quality
of individual wines. In order to understand the genetic diversity of O. oeni, species-specific PCR and 16S rRNA sequence
were used to identify 22 bacterial strains isolated from wines from different producing regions in China. Amplified fragment
length polymorphism (AFLP) based on HindIII and Mse I was developed to analyze the genotypes of 22 O. oeni strains. The
results of species-specific PCR and 16S rRNA sequence analysis showed that the 22 isolates were O. oeni. Double restriction
enzyme digestion and ligation system, PCR reaction system, polyacrylamide gel electrophoresis were developed to analyze
O. oeni. The combinations of 16 AFLP primers were tested. The results showed that HT-MA, HT-MT, HT-MC, HG-MA,
HG-MT, and HC-MT were the optimal primer combinations for analyzing O. oeni. The 22 O. oeni strains were analyzed
by AFLP, and cluster analysis indicated that the 22 O. oeni strains fell into three groups and their genetic similarity
was low. In conclusion, AFLP is a good method to genotype O. oeni by using HindIII and MseI. The O. oeni strains in
China have very rich genetic diversity. The genetic similarity of O.oeni strains is related to their ecological geographic
distribution and other factors.

Key words: Oenococcus oeni, species-specific polymerase chain reaction, 16S rRNA sequence, amplified fragment length polymorphism (AFLP)