Bacterial Community Dynamics of Salted and Fermented Shrimp based on Denaturing Gradient Gel Electrophoresis

Abstract

The Korean traditional seafood jeotgal is consumed directly or as an additive in other foods to improve flavor or fermentation efficiency. Saeujot, made from salted and fermented tiny shrimp (SFS; Acetes japonicus), is the best-selling jeotgal in Korea. In this study, we reveal the microbial diversity and dynamics in naturally fermented shrimp by denaturing gradient gel electrophoresis (DGGE). The population fingerprints of the predominant microbiota and its succession were generated by DGGE analysis of universal V3 16S rDNA polymerase chain reaction (PCR) amplicons. Overall, 17 strains were identified from sequencing of 30 DGGE bands. The DGGE profiles showed diverse bacterial populations in the sample, throughout the fermentation of SFS. Staphylococcus equorum, Halanaerobium saccharolyticum, Salimicrobium luteum, and Halomonas jeotgali were the dominant bacteria, and their levels steadily increased during the fermentation process. Certain other bacteria, such as Psychrobacter jeotgali and Halomonas alimentaria appeared during the early-fermentation process, while Alkalibacterium putridalgicola, Tetragenococcus muriaticus, and Salinicoccus jeotgali appeared during the late-fermentation process. The members of the order Bacillales were found to be predominant during the fermentation of SFS. Furthermore, S. equorum was identified as the dominant bacterial isolate by the traditional method of culturing under aerobic and facultative anaerobic conditions. We expect that this information will facilitate the design of autochthonous starter cultures for the production of SFS with desired characteristic sensory profiles and shorter ripening times.

Characterization of a Fibrinolytic Enzyme Secreted by Bacillus velezensis BS2 Isolated from Sea Squirt Jeotgal

“…Most types of jeotgal are made simply by mixing the raw materials with salt and preserving them for several months before consumption [1]. Various microorganisms have been isolated from jeotgal, and identified by cultural methods and/or culture-independent methods [2][3][4][5][6]. Due to the high salinity of most jeotgal types (20-30%, NaCl), halophilic and halotolerant microorganisms can grow during jeotgal fermentation, and they are believed to contribute to the development of the varied and unique flavors of jeotgal.…”

Comparative phylogeny of the Bacillaceae species related to shrimp paste products

“…Unfortunately, information regarding microbial diversity of the shrimp paste products is scarce compared to that of other products (i.e., fermented dairy and soybean products). Recently, Han et al (2014) described the microbial dynamics and succession during the fermentation of Jeotgal, a Korean fermented shrimp. Using the denaturing gradient gel electrophoresis technique, they found that a diverse group of bacteria was present in which the members of the order Bacillales were predominant (Han et al 2014).…”

“…However, the Proteobacteria members are found at the beginning and replaced by those of the Firmicutes during the fermentation (Lee et al 2014). Han et al (2014) also pointed out that the bacterial members of the order Bacillales are predominant during Saeujot's fermentation. The incidence of this particular bacterial group is expected considering from the selective condition provided for the shrimp paste fermentation.…”

“…The pioneering research work of the shrimp paste's microbiota probably comes from Korean Saeujot in which its microbial population was determined using the molecular approach (Han et al 2014;Lee et al 2014). This research showed that a diverse group of bacteria is present including those in the phyla Proteobacteria and Firmicutes.…”

Bio-Preservation of Refrigerated Peeled Shrimp (Parapenaeus Longirostris) Using Cactus Fruit Peels Polyphenolic Extract

“…Therefore, characterization of microbial communities is important for providing objective quality indices to determine shelf life in seafood. For instance, the microflora of processed (chilled, cooked, peeled, packed, salted and fermented) shrimp has been largely studied using selective culture media (Mejlholm et al, 2005;Laursen et al, 2006;Han et al, 2014). Culture-independent methods are also being increasingly used to develop a complete overview of the bacterial community characteristics.…”