Journal of Animal Science and Technology
Korean Society of Animal Science and Technology

Optimizing growth condition of Bifidobacterium animalis subsp. lactis JNU306 in the yeast extract-peptone-glucose medium using response surface methodology’

Thi Dang1,2, Cheng-Chung Yong1, Sungsue Rheem3,*, Sejong Oh1,**
1Chonnam National University, Gwangju 61186, Korea.
2Western Highlands Agriculture and Forestry Science Institute, Buon Ma Thuot 862097, Viet Nam.
3Graduate School of Public Administration, Korea University, Sejong 30019, Korea.
**Corresponding Author: Sungsue Rheem, Graduate School of Public Administration, Korea University, Sejong 30019, Korea, Republic of. E-mail:
**Corresponding Author: Sejong Oh, Chonnam National University, Gwangju 61186, Korea, Republic of. Phone: 062-530-2116. E-mail:

© Copyright 2021 Korean Society of Animal Science and Technology. This is an Open-Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License ( which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Received: Jan 26, 2021; Revised: Feb 02, 2021; Accepted: Feb 04, 2021

Published Online: Feb 05, 2021


This research improved the growth potential of <italic>Bifidobacterium animalis </italic>subsp<italic> lactis </italic>strain JNU306 in yeast extract, soy peptone, glucose, L-cysteine, and ferrous sulfate, a commercial medium that is appropriate for large-scale production. An initial screening study using a 2<sup>5 </sup>full factorial design was conducted to identify the impact of the various components of the medium on cell mass. Statistical analysis suggested that yeast extract, peptone soy, and L-cysteine had significant effects on the viable cell count. Response surface methodology (RSM) was then used to optimize the components of this medium, using a central composite design and subsequent analyses. A second-order polynomial regression model, which was fitted to the data at first, significantly lacked fitness. Thus, through further analyses, the model with linear and quadratic terms plus two-way, three-way, and four-way interactions was selected as the final model. Through this model, the optimized medium composition was found as 2.8791% yeast extract, 2.8030% peptone soy, 0.6196% glucose, 0.2823% L-cysteine, and 0.0055% ferrous sulfate, w/v. This optimized medium ensured that the maximum biomass was no lower than the biomass from the commonly used BL medium. The application of RSM improved the biomass production of this strain in a more cost-effective way by creating an optimum medium. This result shows that <italic>B. animalis </italic>subsp<italic> lactis </italic>JNU306 may be used as a commercial starter culture in manufacturing probiotics, including dairy products.

Keywords: Bifidobacterium animalis; medium; growth; optimization; RSM; response surface