Effect of protective agents, freezing temperature, rehydration media on viability of malolactic bacteria subjected to freeze-drying
Article first published online: 11 APR 2005
Journal of Applied Microbiology
Volume 99, Issue 2, pages 333–338, August 2005
How to Cite
Zhao, G. and Zhang, G. (2005), Effect of protective agents, freezing temperature, rehydration media on viability of malolactic bacteria subjected to freeze-drying. Journal of Applied Microbiology, 99: 333–338. doi: 10.1111/j.1365-2672.2005.02587.x
- Issue published online: 16 JUN 2005
- Article first published online: 11 APR 2005
- 2004/1213: received 21 October 2004, revised 9 January 2005 and accepted 10 January 2005
- lactic acid bacteria;
- malolactic fermentation;
Aims: The effects of protective agents, rehydration media and freezing temperature on the viabilities of Lactobacillus brevis and Oenococcus oeni H-2 when subjected to freeze-drying were investigated.
Methods and Results: Several protectants and rehydration media were tested to improve the survival after freeze-drying. The cells were also frozen at −65 and −20°C to check the effect of freezing temperature on the viability.
Conclusions: The best protectant and rehydration medium to obtain the highest viability after freeze-drying varied with the species of bacteria. Yeast extract (4·0%) and sodium glutamate (2·5% ) gave maximum viability of L. brevis and O. oeni (67·8% and 53·6% respectively). The highest survival of L. brevis and O. oeni were obtained when rehydrated with 10% sucrose and MGY medium respectively. When the bacterial cells were frozen quickly (−65°C) than slowly (−20°C), L. brevis and O. oeni both showed increased viability after freeze-drying.
Significance and Impact of the Study: The viabilities of L. brevis and O. oeni after freeze-drying were shown to be strain specific and dependent on protective agents, rehydration media and freezing temperature.