Spoilage microbial community profiling by 16S rRNA amplicon sequencing of modified atmosphere packaged live mussels stored at 4oC

There is little information on the microbial communities associated with modified atmosphere (MA)-packaged live mussels. There is also a dearth of information on how pre-packaging depuration modifies the microbial communities and spoilage of live mussels. Amplicon sequencing was used to describe spoilage microbial succession in MA-packaged live mussels during storage at 4 °C. Proteobacteria, Cyanobacteria and Firmicutes were the three major phyla observed in the mussel meat and pouch water of undepurated and depurated mussels. Among these phyla, Cyanobacteria was more predominant on day 0 in mussel meat of undepurated and depurated mussels while Proteobacteria was predominant in commercially-depurated mussels. <em>Synechococcus</em> was apparently dominant on days 0–7 in the meat of undepurated mussels and days 0–10 in depurated mussels. <em>Shewanella</em> was dominant on day 0 in commercially-depurated mussels and dominant on day 15 in undepurated while <em>Acidaminococcus</em> was dominant in depurated mussels on day 15. <em>Psychromonas</em> was observed to be dominant in commercially-depurated mussels on day 7 and further shifted to <em>Acinetobacter</em> by day 10 and 15. In the pouch water, <em>Acinetobacter</em> was dominant throughout the storage days in undepurated mussels while <em>Psychrobacter</em> was predominant in both depurated and commercially-depurated mussels. This study demonstrated the impact of depuration on the microbiota and the spoilage mechanism of MA-packaged live mussels. <em>Shewanella</em> was easily removed through depuration. However, spoilage bacteria such as <em>Acidaminococcus</em> could not be easily removed although they are not important at the beginning but grew at the end. Pouch water contributed suitable biological medium for the growth of <em>Acinetobacter</em> and <em>Psychrobacter</em> and both enhanced the growth of spoilage bacteria such as <em>Shewanella</em> and <em>Acidaminococcus</em>.