Pyrosequencing-based analysis of the bacterial community during fermentation of Alaska pollock sikhae: traditional Korean seafood

We analyzed the bacterial community of Alaska pollock sikhae, a traditional Korean food made by natural fermentation with Alaska pollock, utilizing pyrosequencing. We fermented the Alaska pollock sikhae at two different temperatures (10°C and 20°C). Before fermentations, the bacterial community was varied. After fermentations, however, Lactobacillus sakei became dominant. The Alaska pollock sikhae sample before fermentations contained only 2% L. sakei, but the sample on day 6 of fermentation at 10°C comprised 74% L. sakei (90% at 20°C). In addition, we observed a reduction in the composition of unpreferred bacterial species for foods after fermentation. The composition of unpreferred bacterial species was more than 30% of total reads in samples before fermentation and decreased to less than 0.2% after fermentation. This result suggested that the fermentation of Alaska pollock sikhae can be beneficial for food safety. Alaska pollock sikhae might be a favorable habitat for L. sakei. Our study is the first report illustrating the alteration of the bacterial community of Alaska pollock sikhae during fermentation utilizing pyrosequencing analysis.