Transcriptome Analysis of Halotolerant Staphylococcus saprophyticus Isolated from Korean Fermented Shrimp

Abstract

Saeu-jeotgal, a Korean fermented shrimp food, is commonly used as an ingredient for making kimchi and other side dishes. The high salinity of the jeotgal contributes to its flavor and inhibits the growth of food spoilage microorganisms. Interestingly, Staphylococcus saprophyticus was discovered to be capable of growth even after treatment with 20% NaCl. To elucidate the tolerance mechanism, a genome-wide gene expression of S. saprophyticus against 0%, 10%, and 20% NaCl was investigated by RNA sequencing. A total of 831, 1314, and 1028 differentially expressed genes (DEGs) were identified in the 0% vs. 10%, 0% vs. 20%, and 10% vs. 20% NaCl comparisons, respectively. The Clusters of Orthologous Groups analysis revealed that the DEGs were involved in amino acid transport and metabolism, transcription, and inorganic ion transport and metabolism. The functional enrichment analysis showed that the expression of the genes encoding mechanosensitive ion channels, sodium/proton antiporters, and betaine/carnitine/choline transporter family proteins was downregulated, whereas the expression of the genes encoding universal stress proteins and enzymes for glutamate, glycine, and alanine synthesis was upregulated. Therefore, these findings suggest that the S. saprophyticus isolated from the saeu-jeotgal utilizes different molecular strategies for halotolerance, with glutamate as the key molecule.

Microbiological and chemical characteristics of porkfish inasua, traditional fish fermented from Maluku, Indonesia

“…Some bacterial strains were also considered pathogens because they colonize the human rectum and urogenital tract (Devi et al 2015). The S. saprophyticus strain found in jeotgal (a fermented shrimp product from Korea) was not pathogenic (Jo et al 2022). Porkfish as the raw material for inasua has a high protein content (>18%) (Đorđević et al 2016).…”

Understanding the mechanisms of halotolerance in members of Pontixanthobacter and Allopontixanthobacter by comparative genome analysis

“…For instance, comparative transcriptomic and physiological analysis revealed that the halotolerant bacterium Egicoccus halophilus EGI 80432 T increased inorganic ions uptake and accumulated trehalose and glutamate in response to moderate salinity condition, while the high salt condition led to up-regulated transcription of genes required for the synthesis of compatible solutes, such as glutamate, histidine, threonine, proline, and ectoine ( Chen et al, 2021 ). The role of glutamate as a key compatible solute for halotolerance was also reported in a halotolerant strain of Staphylococcus saprophyticus based on transcriptome comparison of cells cultivated in media containing different concentrations of NaCl (0, 10, and 20%; Jo et al, 2022 ). In the exoproteome of the halotolerant bacterium Tistlia consotensis grown at high salinity, proteins associated with osmosensing, exclusion of Na + and transport of compatible solutes, such as glycine betaine or proline are abundant ( Rubiano-Labrador et al, 2015 ).…”

The Biological Responses of Staphylococcus aureus to Cold Plasma Treatment

“…This disparity between treatments might be due to S. aureus's response to the sudden exposure of cold plasma in the early treatment (T1), where more RNA encode for stress proteins were generated than in the other treatments (T3 and T5). Other research revealed each stress protein can be regulated by different stress conditions, such as Gls24 family stress response protein, which can be induced by aerated conditions [29] and copper stress [30], and GlsB/YeaQ/YmgE family stress response protein, which is possibly related to butanol [31] and salt tolerance [32]. A total of six DEGs related to antioxidants were identified in cold plasma-treated S. aureus, all of which were upregulated (three in T1/T3/T5), please refer to (b) in Table 2.…”