Non-inhibitory levels of oxygen during cultivation increase freeze-drying stress tolerance in Limosilactobacillus reuteri DSM 17938
(2023) In Frontiers in Microbiology 14.- Abstract
- The physiological effects of oxygen on Limosilactobacillus reuteri DSM 17938 during cultivation and the ensuing properties of the freeze-dried probiotic product was investigated. On-line flow cytometry and k-means clustering gating was used to follow growth and viability in real time during cultivation. The bacterium tolerated aeration at 500 ml/min, with a growth rate of 0.74 ± 0.13 h-1 which demonstrated that low levels of oxygen did not influence the growth kinetics of the bacterium. Modulation of the redox metabolism was, however, seen already at non-inhibitory oxygen levels by 1.5-fold higher production of acetate and 1.5-fold lower ethanol production. A significantly higher survival rate in the freeze-dried product was observed for... (More)
- The physiological effects of oxygen on Limosilactobacillus reuteri DSM 17938 during cultivation and the ensuing properties of the freeze-dried probiotic product was investigated. On-line flow cytometry and k-means clustering gating was used to follow growth and viability in real time during cultivation. The bacterium tolerated aeration at 500 ml/min, with a growth rate of 0.74 ± 0.13 h-1 which demonstrated that low levels of oxygen did not influence the growth kinetics of the bacterium. Modulation of the redox metabolism was, however, seen already at non-inhibitory oxygen levels by 1.5-fold higher production of acetate and 1.5-fold lower ethanol production. A significantly higher survival rate in the freeze-dried product was observed for cells cultivated in presence of oxygen compared to absence of oxygen (61.8 ± 2.4 % vs 11.5 ± 4.3 %), coinciding with a higher degree of unsaturated fatty acids (UFA:SFA ratio of 10 for air sparged vs 3.59 for N2 sparged conditions.). Oxygen also resulted in improved bile tolerance and boosted 5’nucleotidase activity (370 U/L vs 240 U/L in N2 sparged conditions) but lower tolerance to acidic conditions compared bacteria grown under complete anaerobic conditions which survived up to 90 min of exposure at pH 2. Overall, our results indicate the controlled supply of oxygen during production may be used as means for probiotic activity optimisation of L. reuteri DSM 17938. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/90cb197c-6ef9-4b5b-8f94-9e84db07e20c
- author
- Seshagiri Rao, Nikhil LU ; Ermann Lundberg, Ludwig ; Tomasson, Julia ; Tullberg, Cecilia LU ; Brink, Daniel P. LU ; Bai Palmkron, Shuai LU ; van Niel, Ed W. J. LU ; Håkansson, Sebastian LU and Carlquist, Magnus LU
- organization
- publishing date
- 2023
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Online flow cytometry, K Mean clustering, Fatty acid (FA), Bile and Acid Tolerance, 5' Nucleotidase, Limosilactobacillus reuteri DSM 17938, Oxygen, Freeze-drying (FD)
- in
- Frontiers in Microbiology
- volume
- 14
- article number
- 1152389
- pages
- 13 pages
- publisher
- Frontiers Media S. A.
- external identifiers
-
- scopus:85159792351
- pmid:37125176
- ISSN
- 1664-302X
- DOI
- 10.3389/fmicb.2023.1152389
- language
- English
- LU publication?
- yes
- id
- 90cb197c-6ef9-4b5b-8f94-9e84db07e20c
- date added to LUP
- 2023-03-22 19:56:24
- date last changed
- 2024-01-05 00:13:54
@article{90cb197c-6ef9-4b5b-8f94-9e84db07e20c, abstract = {{The physiological effects of oxygen on Limosilactobacillus reuteri DSM 17938 during cultivation and the ensuing properties of the freeze-dried probiotic product was investigated. On-line flow cytometry and k-means clustering gating was used to follow growth and viability in real time during cultivation. The bacterium tolerated aeration at 500 ml/min, with a growth rate of 0.74 ± 0.13 h-1 which demonstrated that low levels of oxygen did not influence the growth kinetics of the bacterium. Modulation of the redox metabolism was, however, seen already at non-inhibitory oxygen levels by 1.5-fold higher production of acetate and 1.5-fold lower ethanol production. A significantly higher survival rate in the freeze-dried product was observed for cells cultivated in presence of oxygen compared to absence of oxygen (61.8 ± 2.4 % vs 11.5 ± 4.3 %), coinciding with a higher degree of unsaturated fatty acids (UFA:SFA ratio of 10 for air sparged vs 3.59 for N2 sparged conditions.). Oxygen also resulted in improved bile tolerance and boosted 5’nucleotidase activity (370 U/L vs 240 U/L in N2 sparged conditions) but lower tolerance to acidic conditions compared bacteria grown under complete anaerobic conditions which survived up to 90 min of exposure at pH 2. Overall, our results indicate the controlled supply of oxygen during production may be used as means for probiotic activity optimisation of L. reuteri DSM 17938.}}, author = {{Seshagiri Rao, Nikhil and Ermann Lundberg, Ludwig and Tomasson, Julia and Tullberg, Cecilia and Brink, Daniel P. and Bai Palmkron, Shuai and van Niel, Ed W. J. and Håkansson, Sebastian and Carlquist, Magnus}}, issn = {{1664-302X}}, keywords = {{Online flow cytometry; K Mean clustering; Fatty acid (FA); Bile and Acid Tolerance; 5' Nucleotidase; Limosilactobacillus reuteri DSM 17938; Oxygen; Freeze-drying (FD)}}, language = {{eng}}, publisher = {{Frontiers Media S. A.}}, series = {{Frontiers in Microbiology}}, title = {{Non-inhibitory levels of oxygen during cultivation increase freeze-drying stress tolerance in <i>Limosilactobacillus reuteri</i> DSM 17938}}, url = {{https://lup.lub.lu.se/search/files/144244901/fmicb_14_1152389.pdf}}, doi = {{10.3389/fmicb.2023.1152389}}, volume = {{14}}, year = {{2023}}, }