کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
3701 | 182 | 2011 | 5 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Unstructured model for free and immobilized cell culture without pH control of Bifidobacterium animalis subsp. lactis Bb 12—Inhibitory effect of the undissociated organic acids Unstructured model for free and immobilized cell culture without pH control of Bifidobacterium animalis subsp. lactis Bb 12—Inhibitory effect of the undissociated organic acids](/preview/png/3701.png)
A model was developed to describe growth and organic acids production of Bifidobacterium animalis growing without pH control in free and immobilized cell culture. The Verlhust model was considered for growth, and to account for the inhibition observed at acidic pH, the Luedeking–Piret production model was modified by introducing an additional term involving the undissociated form of the organic acids, acetic and lactic acids, the main inhibitory species. To describe the relationship between pH and both the dissociated and the undissociated forms of organic acids, the Henderson–Hasselbach equation was considered. The model was found to satisfactory describe experimental growth and production data recorded during free and immobilized cell cultures. The part of each acid produced can be deduced from the calculated production data, since a constant lactic to acetic acid mass ratio was found, 1.29 and 1.66 during free and immobilized cell cultures. Owing to the acidic pH values recorded, 4.43 at lowest, higher amounts of undissociated acetic acid were produced, leading to a higher inhibitory effect of this acid if compared to lactic acid.
► A model was developed to describe growth and organic acids production of B. animalis.
► The Verlhust and a modified Luedeking–Piret models were considered.
► An additional term involving the undissociated form of the acids was introduced.
► Data recorded during free and immobilized cell cultures were satisfactory described.
► The part of lactic and acetic acids produced can be calculated from production data.
Journal: Biochemical Engineering Journal - Volumes 58–59, 15 December 2011, Pages 184–188