High-Density Fermentation of <i>Lactobacillus plantarum</i> P6: Enhancing Cell Viability via Sodium Alginate Enrichment

Abstract

Lactobacillus plantarum exhibits a wide range of beneficial physiological functions, including maintaining intestinal microbiota balance, reducing serum cholesterol, and promoting digestive health. According to the specific nutrient requirements of Lactobacillus plantarum P6, we investigated the effects of various carbon sources, nitrogen sources, trace elements, growth-promoting substances, as well as the initial pH and inoculum size on the growth of Lactobacillus plantarum P6 under fermentation conditions. The optimal growth conditions for Lactobacillus plantarum P6 were identified to facilitate high-density fermentation in small-scale fermenter production, achieving a cell concentration of 1.03 × 1011 CFU/mL. This resulted in a 2.5-fold increase in bacterial wet weight, and fermentation time was reduced to 12 h when utilizing a specific medium enriched with 0.2% sodium alginate. It is hypothesized that sodium alginate forms a protective film around the bacterial cells, promoting cell aggregation and enhancing self-coalescence, potentially triggering a bacterial community effect. These results provide a basis for the industrial-scale high-density cultivation of Lactobacillus plantarum, offering potential for enhanced biotechnological applications.

Keywords

• LAB
• fermentation optimization
• high-density fermentation
• response surface analysis
• total colony count