Influence of lyophilization, fluidized bed drying, addition of protectants, and storage on the viability of lactic acid bacteria.
OBJECTIVE
The present study focuses on the impact of two different drying technologies and the influence of protectants on process survival and storage stability of the two lactic acid bacterial strains Enterococcus faecium and Lactobacillus plantarum.


RESULTS
After incubation with the protectants glucose, sucrose, trehalose, and maltodextrin the concentrated bacterial suspensions were subjected to fluidized bed drying and lyophilization and subsequently stored at 4, 22, and 35 degrees C for half a year. Lactobacillus plantarum turned out to be more sensitive to both drying methods than Ent. faecium. Without the addition of a protectant cells of both strains suffered higher losses during fluidized bed drying. Elevated storage temperatures correlate with a higher decline of viable bacterial cells.


CONCLUSIONS
Although survival rates varied between the strains, the nonreducing disaccharides revealed overall best protection for both investigated lactic acid bacteria during processing and storage. The addition of protective carbohydrates can prevent the decline in viability during fluidized bed drying.


CONCLUSIONS
The influence of protectants proved to be species specific and therefore needs to be determined on a case-to-case basis. Survival rates, duration, and energy consumption appear to be the crucial parameters to evaluate the economy of production processes for industrial starter cultures.
Strasser
S
S
Institute for Environmental Biotechnology, Department for Agrobiotechnology, IFA-Tulln, University of Natural Resources and Applied Life Sciences, Vienna, Tulln, Austria.
Neureiter
M
M
Geppl
M
M
Braun
R
R
Danner
H
H
D018929:Cell Culture Techniques / Q000379:methods; D002470:Cell Survival; D015169:Colony Count, Microbial; D015925:Cryopreservation; D003451:Cryoprotective Agents / Q000494:pharmacology*; D003470:Culture Media; D003681:Dehydration; D003890:Desiccation / Q000379:methods*; D016984:Enterococcus faecium / Q000187:drug effects / Q000254:growth & development*; D005612:Freeze Drying / Q000379:methods*; D005947:Glucose / Q000494:pharmacology; D048191:Lactiplantibacillus plantarum / Q000187:drug effects / Q000254:growth & development*; D011134:Polysaccharides / Q000494:pharmacology; D013395:Sucrose / Q000494:pharmacology; D013696:Temperature; D014199:Trehalose / Q000494:pharmacology
D003451:Cryoprotective Agents; D003470:Culture Media; D011134:Polysaccharides; D013395:Sucrose; C008315:maltodextrin; D014199:Trehalose; D005947:Glucose