Supercooling Pretreatment Improves the Shelf-Life of Freeze-Dried < em > Leuconostoc mesenteroides < /em > WiKim32

J Microbiol Biotechnol. 2022 Oct 26;32(12):1-6. doi: 10.4014/jmb.2209.09022. Online ahead of print.ABSTRACTStorage stability of freeze-dried lactic acid bacteria is a critical factor for their cost-effectiveness. Long-term storage of lactic acid bacteria enables microbial industry to reduce distribution costs. Herein, we investigated the effect of cold adaptation under supercooling conditions at -5oC on the viability of Leuconostoc mesenteroides WiKim32 during the freeze-drying process and subsequent storage. Cold adaptation increased the thickness of exopolysaccharides (EPS) and improved the viability of freeze-dried Leu. mesenteroides WiKim32. Compared to non-adapted cells, cold-adapted cells showed a 35.4% increase in EPS thickness under supercooling conditions. The viability of EPShydrolyzed cells was lower than that of untreated cells, implying that EPS plays a role in protection during the freeze-drying process. Cold adaptation increased the storage stability of freeze-dried Leu. mesenteroides WiKim32. Fifty-six days after storage, the highest viability (71.3%) was achieved with cold adaptation at -5oC. When EPS-containing broth was added prior to the freeze-drying process, the viability further increased to 82.7%. These results imply that cold adaptation by supercooling pretreatment would be a good strategy for the long-term storage of Leu. mesenteroides WiKim32.PMID:36330746 | DOI:10.4014/jmb.2209.09022
Source: Journal of Microbiology and Biotechnology - Category: Biotechnology Authors: Source Type: research