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Real-time metabolomic analysis of lactic acid bacteria as monitored by in vitro NMR and chemometrics

Ebrahimi, Parvaneh LU ; Larsen, Flemming Hofmann; Jensen, Henrik Max; Vogensen, Finn Kvist and Engelsen, Søren Balling (2016) In Metabolomics 12(4).
Abstract

Introduction: Lactic acid bacteria (LAB) play an important role in the food industry as starter cultures to manufacture fermented food, and as probiotics. In recent years, there has been an increasing interest in using LAB cultures for biopreservation of food products. It is therefore of great interest to study the detailed metabolism of these bacteria. Objectives: This study aimed at developing an efficient analytical protocol for real-time in vitro NMR measurements of LAB fermentations, from sample preparation, over data acquisition and preprocessing, to the extraction of the kinetic metabolic profiles. Method: The developed analytical protocol is applied to an experimental design with two LAB strains (Lactobacillus rhamnosus DSM... (More)

Introduction: Lactic acid bacteria (LAB) play an important role in the food industry as starter cultures to manufacture fermented food, and as probiotics. In recent years, there has been an increasing interest in using LAB cultures for biopreservation of food products. It is therefore of great interest to study the detailed metabolism of these bacteria. Objectives: This study aimed at developing an efficient analytical protocol for real-time in vitro NMR measurements of LAB fermentations, from sample preparation, over data acquisition and preprocessing, to the extraction of the kinetic metabolic profiles. Method: The developed analytical protocol is applied to an experimental design with two LAB strains (Lactobacillus rhamnosus DSM 20021 and Lactobacillus plantarum subsp. plantarum DSM 20174), two initial pH levels (pHi 6.5 and 5.5), two levels of glucose concentration (2.5 and 0.25 g/l), and two batch fermentation replicates. Results: The design factors proved to be strongly significant and led to interesting biological information. The protocol allowed for detailed real-time kinetic analysis of 11 major metabolites involved in the glycolysis, pyruvate catabolism, amino acid catabolism and cell energy metabolism. New biological knowledge was obtained about the different patterns of glutamine and aspartic acid consumption by the two strains. It was observed that L. plantarum consumes more glutamine at low pH (pH 5.5) whereas the opposite applies to L. rhamnosus. Regarding aspartic acid, both of the strains consume it higher at low pH, and overall L. plantarum consumes it more. L. rhamnosus did not consume aspartic acid at pH 6.5. Conclusion: The developed analytical protocol for real-time in vitro NMR measurements of bacterial metabolism allows a relatively easy investigation of different fermentation factors such as new strains, new substrates, cohabitations, temperature, and pH and has a great potential in biopreservation studies to discover new efficient bioprotective cultures.

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author
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Fermentation, In vitro NMR, Lactic acid bacteria, Modelling metabolic profiles, Multivariate curve resolution, Reference deconvolution
in
Metabolomics
volume
12
issue
4
pages
17 pages
publisher
Springer
external identifiers
  • scopus:84961218900
ISSN
1573-3882
DOI
10.1007/s11306-016-0996-7
language
English
LU publication?
no
id
5be59850-1a54-413a-a4f1-53ee9b226f44
date added to LUP
2019-06-24 12:24:26
date last changed
2019-10-23 06:19:19
@article{5be59850-1a54-413a-a4f1-53ee9b226f44,
  abstract     = {<p>Introduction: Lactic acid bacteria (LAB) play an important role in the food industry as starter cultures to manufacture fermented food, and as probiotics. In recent years, there has been an increasing interest in using LAB cultures for biopreservation of food products. It is therefore of great interest to study the detailed metabolism of these bacteria. Objectives: This study aimed at developing an efficient analytical protocol for real-time in vitro NMR measurements of LAB fermentations, from sample preparation, over data acquisition and preprocessing, to the extraction of the kinetic metabolic profiles. Method: The developed analytical protocol is applied to an experimental design with two LAB strains (Lactobacillus rhamnosus DSM 20021 and Lactobacillus plantarum subsp. plantarum DSM 20174), two initial pH levels (pH<sub>i</sub> 6.5 and 5.5), two levels of glucose concentration (2.5 and 0.25 g/l), and two batch fermentation replicates. Results: The design factors proved to be strongly significant and led to interesting biological information. The protocol allowed for detailed real-time kinetic analysis of 11 major metabolites involved in the glycolysis, pyruvate catabolism, amino acid catabolism and cell energy metabolism. New biological knowledge was obtained about the different patterns of glutamine and aspartic acid consumption by the two strains. It was observed that L. plantarum consumes more glutamine at low pH (pH 5.5) whereas the opposite applies to L. rhamnosus. Regarding aspartic acid, both of the strains consume it higher at low pH, and overall L. plantarum consumes it more. L. rhamnosus did not consume aspartic acid at pH 6.5. Conclusion: The developed analytical protocol for real-time in vitro NMR measurements of bacterial metabolism allows a relatively easy investigation of different fermentation factors such as new strains, new substrates, cohabitations, temperature, and pH and has a great potential in biopreservation studies to discover new efficient bioprotective cultures.</p>},
  articleno    = {77},
  author       = {Ebrahimi, Parvaneh and Larsen, Flemming Hofmann and Jensen, Henrik Max and Vogensen, Finn Kvist and Engelsen, Søren Balling},
  issn         = {1573-3882},
  keyword      = {Fermentation,In vitro NMR,Lactic acid bacteria,Modelling metabolic profiles,Multivariate curve resolution,Reference deconvolution},
  language     = {eng},
  month        = {04},
  number       = {4},
  pages        = {17},
  publisher    = {Springer},
  series       = {Metabolomics},
  title        = {Real-time metabolomic analysis of lactic acid bacteria as monitored by in vitro NMR and chemometrics},
  url          = {http://dx.doi.org/10.1007/s11306-016-0996-7},
  volume       = {12},
  year         = {2016},
}