Effect of water activity and protective solutes on growth and subsequent survival to air-drying of Lactobacillus and Bifidobacterium cultures

Abstract

Probiotic cultures of Lactobacillus plantarum, Lactobacillus rhamnosus, Bifidobacterium longum, Lactobacillus casei and Lactobacillus acidophilus were grown in media having water activities (a (w)) adjusted between 0.99 and 0.94 with NaCl or with a mixture of glycerol and sucrose in order to find conditions of osmotic stress which would still allow for good growth. Cultures grown at a (w) = 0.96 or 0.99 were then recovered by centrifugation, added to a sucrose-phosphate medium and air-dried. In some assays, a 2-h osmotic stress was applied to the cell concentrate prior to air-drying. Assays were also carried out where betaine, glutamate and proline (BGP) supplements were added as protective compounds to the growth or drying media. For most strains, evidence of osmotic stress and benefits of BGP supplementation on growth occurred at a (w) = 0.96. Growing the cells in complex media adjusted at a (w) = 0.96 did not enhance their subsequent survival to air-drying, but applying the 2-h osmotic stress did. Addition of the BGP supplements to the growth medium or in the 2-h stress medium did not enhance survival to air-drying. Furthermore, addition of BGP to a sucrose-phosphate drying medium reduced survival of the cultures to air-drying. This study provides preliminary data for producers of probiotics who wish to use air-drying in replacement of freeze-drying for the stabilization of cultures.

Next Generation Drying Technologies for Pharmaceutical Applications

“…Champagne et al examined the stability of various probiotic cultures, including Lactobacillus rhamnosus ( L. rhamnosus ) and Lactobacillus plantarum ( L. plantarum ) upon air drying. Samples were exposed to dehumidified air (<5% RH) at 90 L/h and dried for 24 h at room temperature in the presence of supersaturated solution of lithium chloride to control water activity.…”

“…Yeast, 29 probiotics, 30 proteins, 31,32 antibodies, 33 enzymes, 34 platelets, 35 fish, 36 encountered in developing an efficient drying process. Depending on the energy source and the configuration of the drying system, the parameters to be optimized will differ, as will be described below.…”

Optimization of air-blast drying process for manufacturing Saccharomyces cerevisiae and non-Saccharomyces yeast as industrial wine starters

“…Even though air-blast drying has many advantages for making yeast starters, only a few studies related to the air-blast dried yeast have been attempted. Similar to freeze-drying, the selection of protective agents is very important in air-blast drying because intracellular accumulation of the appropriate solutes is related to strain survival following air-blast drying (Kets et al 1996; Champagne et al 2012). Suitable agents can protect the proteins and membranes of the microorganisms (Leslie et al 1995; Champagne and Gardner 2001).…”

The use of flow cytometry to accurately ascertain total and viable counts of Lactobacillus rhamnosus in chocolate

“…The beads (approximately 180 g) were collected with a Buchner funnel, rinsed with 800 mL of a 5.5 g/L calcium chloride solution, collected again, and soaked in the protective freezedrying medium composed of 100 g/L maltodextrin (10 DE StarDri 100; Continental Ingredients Canada, Oakville, ON, CA), 100 g/L glycerol (Sigma), 20 g/L yeast extract (Difco) and 4 g/L sodium ascorbate (Sigma). After soaking for 20 min at room temperature, the beads were collected and air-dried (5% relative humidity) in a modified desiccator (Champagne et al, 2012). The DAME beads were subsequently kept frozen (À20 C) in a glass jar in which the headspace was flushed with nitrogen gas.…”