Effects of exogenous amino acids on the freeze-drying survival rate of Lactiplantibacillus plantarum LIP-1

Abstract

How to improve the freeze-drying survival rate of Lactic acid bacteria (LAB) by increasing its resistance is a problem that is worth paying attention to. We evaluated the effect of exogenous amino acids on freeze-drying resistance of strain using Lactiplantibacillus plantarum LIP-1 as model probiotics. We found that the survival rate of L. plantarum LIP-1 after freeze-dried could be significantly enhanced by adding 0.04 g/L glycine to medium (p < 0.05), compare with other amino acids. Mechanistic studies showed that the content of peptidoglycan was increased to improve the integrity of the cell wall via metabolizing glycine; By metabolizing glycine, the content of unsaturated fatty acid was increased, such as C19cyc11, to promote membrane fluidity. In addition, the metabolism of glycine could neutralize the acidic intracellular environment to reduce DNA damage, thus improve the survival rate of freeze-dried strain. These findings may provide a new idea for industrialization of LAB powder.

Keywords:

• Lactiplantibacillus plantarum LIP-1
• glycine
• freeze-drying survival rate
• cell wall
• cell membrane
• DNA

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the National Natural Science Foundation of China [grant numbers 31660456] and 2022 Inner Mongolia Autonomous Region at the same level of public institutions to introduce high-level talent research support funds [grant numbers DC2300001256]. The English in this document has been checked by at least two professional editors, both native speakers of English. For a certificate, please see: http://www.textcheck.com/certificate/u6CgFB