Optimizing Cold Fermentation of Oyster Sikhye with the Novel *L. citreum* SH-02 Bacterial Strain

Researchers have successfully validated the industrial viability of utilizing the *Leuconostoc citreum* SH-02 bacterial strain as a foundational starter culture for the cold fermentation process applied to Sikhye made from oysters. This traditional Korean delicacy benefits significantly from this breakthrough. The achievement marks a major stride in tackling the inherent challenges associated with fermenting seafood products. Specifically, this method ensures robust microbial activity and maintains product safety, even when stored at low temperatures, paving a clear path for commercial-scale production.

Lactic acid microorganisms, which include species within the *Leuconostoc* genus, are pivotal players in food biotechnology. They are responsible for transforming raw materials and imparting entirely new organoleptic characteristics. The newly developed *L. citreum* SH-02 strain exhibits remarkable efficiency in acidifying the medium. Crucially, this action simultaneously inhibits the proliferation of undesirable spoilage-causing microorganisms. This dual mechanism guarantees the preservation of the authentic flavor profile and helps achieve the precise texture required in the final product. Sensory evaluations have confirmed an enhancement in taste qualities, noting a well-balanced acidity alongside a pronounced umami note—factors that are absolutely critical to consumer acceptance.

A fundamental aspect of food safety, particularly for fermented seafood items, is stringent control over the creation of toxic biogenic amines. The implementation of this specific culture ensures this control is maintained. Through detailed molecular analysis, scientists were able to pinpoint the specific gene clusters responsible for the unique cold tolerance and high efficacy demonstrated by the *L. citreum* SH-02 strain under low-temperature processing conditions. Unlike older techniques that necessitated heat treatment, employing this standardized starter culture dramatically streamlines the production cycle and minimizes the batch-to-batch variability that plagues traditional methods.

In the broader context of biotechnology, other members of the *Leuconostoc* genus, such as *L. mesenteroides*, are commonly employed to kickstart the fermentation of vegetable-based raw materials. However, adapting and applying specialized strains, like *L. citreum* SH-02, to sensitive seafood products such as oyster Sikhye signals a deepening level of control over biotechnological processes. The controlled fermentation facilitated by this culture allows manufacturers to confidently promise consumers a consistent profile of taste and texture, alongside adherence to strict regulatory limits concerning undesirable metabolites.

The integration of this novel technology shifts the industry focus away from lengthy, energy-intensive warm fermentation methods toward more sustainable and highly manageable low-temperature biotechnological solutions. Processes conducted at lower temperatures inherently require less energy input compared to conventional warm fermentations, thereby lessening the overall carbon footprint of production. This development aligns perfectly with the current trajectory within the food industry, which prioritizes enhanced process controllability and greater environmental sustainability across the board.