A synergistic fermentation system of probiotics with low-cost and high butyric acid production: Lactiplantibacillus plantarum and Clostridium tyrobutyricum

Butyric acid plays a significant role in maintaining body health, and thus the research on cost-effective and efficient biological conversion strategies for butyric acid production holds great importance. This study utilized the mutual interactions between prebiotics and multiple probiotic strains to target increasing the butyric acid yield in a co-fermentation system. Briefly, xylan, an inexpensive biomass material, was used as a prebiotic to screen lactic acid bacteria that capable of being promoted for proliferation and metabolism in its presence. Subsequently, the interaction between the screened lactic acid bacteria and a butyric acid-producing strain ( Clostridium tyrobutyricum) ) was utilized to enhance butyric acid production. The results showed that xylan significantly improved the proliferation and lactic acid metabolizing ability of Lactiplantibacillus plantarum C0502. Whole-genome analysis revealed that L. plantarum carries at least four distinct enzyme genes related to the hydrolysis and utilization of xylan. Co-cultivation of L. plantarum with C. tyrobutyricum demonstrated that the C. tyrobutyricum was able to effectively convert lactic and acetic acids into butyric acid. Furthermore, the addition of xylan into this co-culture system yielded a remarkable butyric acid production of up to 5.01 +/- 0.04 g/ L, which is 4.58 times higher than the yield obtained from the monoculture of C. tyrobutyricum in reinforced Clostridium medium. The results of this study suggested that the co-culture system of xylan, L. plantarum, , and C. tyrobutyricum has the potential to significantly enhance butyric acid production while markedly reduce the production cost. This has immense prospects for practical applications.