Optimization of a Bifidobacterium longum production process |
| |
Authors: | Kiviharju Kristiina Leisola Matti Eerikäinen Tero |
| |
Affiliation: | Helsinki University of Technology, Laboratory of Bioprocess Engineering, P.O. Box 6100, FIN-02015 HUT, Finland. kristiina.kiviharju@hut.fi |
| |
Abstract: | Bifidobacteria are used as probiotics mainly in the dairy industry as cell suspensions or as freeze-dried additives. So far there have been no reports on a thorough investigation on factors influencing the production process or a statistical approach to the optimization thereof. A 2(8-4) fractional factorial design was used in determining the critical parameters influencing bioreactor cultivations of Bifidobacterium longum ATCC 15707. Glucose, yeast extract and l-cysteine concentrations were found critical for the cultivation of this strain. Glucose and yeast extract concentrations were further studied together with temperature in a three factor central composite design. The optimized cultivation conditions were temperature 40 degrees C, yeast extract concentration 35 gl(-1) and glucose concentration 20 gl(-1). Freeze-drying of frozen cell suspensions of B. longum was studied first in controlled temperatures and thereafter with temperature programming experiments. The results were statistically evaluated. A temperature program with a 2 h temperature gradient from -10 to 0 degrees C, a 10 h temperature gradient from 0 to +10 degrees C and a 12 h temperature hold at +10 degrees C was found best for the freeze-drying process. Temperature programming reduced drying times by over 50% and improved the product activity by over 160%. |
| |
Keywords: | |
本文献已被 PubMed 等数据库收录! |
|