Characterization, High-Density Fermentation, and the Production of a Directed Vat Set Starter of Lactobacilli Used in the Food Industry: A Review

Abstract

<i>Lactobacilli</i> have been widely concerned for decades. Bacteria of the genus <i>Lactobacillus</i> have been commonly employed in fermented food to improve the appearance, smell, and taste of food or prolong its shelf-life. They comprise 261 species (by March 2020) that are highly diverse at the phenotypic, ecological, and genotypic levels. Some <i>Lactobacilli</i> strains have been documented to be essential probiotics, which are defined as a group of living microorganisms that are beneficial to the health of the host when ingested in sufficiency. However, the characterization, high-density fermentation, and the production of a directed vat set (DVS) starter of <i>Lactobacilli</i> strains used in the food industry have not been systematically reported. This paper mainly focuses on reviewing <i>Lactobacilli</i> as functional starter cultures in the food industry, including different molecular techniques for identification at the species and strain levels, methods for evaluating <i>Lactobacilli</i> properties, enhancing their performance and improving the cell density of <i>Lactobacilli</i>, and the production techniques of DVS starter of <i>Lactobacilli</i> strains. Moreover, this review further discussed the existing problems and future development prospects of <i>Lactobacilli</i> in the food industry. The viability and stability of <i>Lactobacilli</i> in the food industry and gastrointestinal environment are critical challenges at the industrial scale. The new production equipment and technology of DVS starter of <i>Lactobacilli</i> strains will have the potential for large-scale application, for example, developing low-temperature spray drying, freezing granulation drying, and spray freeze-drying.