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Shen Z, Lin L, Zhai Z, Liang J, Chen L, Hao Y, Zhao L. bglG Regulates the Heterogeneity Driven by the Acid Tolerance Response in Lacticaseibacillus paracasei L9. Foods 2023; 12:3971. [PMID: 37959089 PMCID: PMC10650579 DOI: 10.3390/foods12213971] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2023] [Revised: 10/24/2023] [Accepted: 10/28/2023] [Indexed: 11/15/2023] Open
Abstract
The acid tolerance of lactic acid bacteria is crucial for their fermentation and probiotic functions. Acid adaption significantly enhances the acid tolerance of strains, and the phenotypic heterogeneity driven by the acid tolerance response (ATR) contributes to this process by providing a selective advantage in harsh environments. The mechanism of heterogeneity under the ATR is not yet clear, but individual gene expression differences are recognized as the cause. In this study, we observed four heterogeneous subpopulations (viable, injured, dead, and unstained) of Lacticaseibacillus paracasei L9 (L9) induced by acid adaption (pH 5.0, 40 min) using flow cytometry. The viable subpopulation represented a significantly superior acid tolerance to the injured subpopulation or total population. Different subpopulations were sorted and transcriptomic analysis was performed. Five genes were found to be upregulated in the viable subpopulation and downregulated in the injured subpopulation, and bglG (LPL9_RS14735) was identified as having a key role in this process. Using salicin (glucoside)-inducing gene expression and gene insertion mutagenesis, we verified that bglG regulated the heterogeneity of the acid stress response and that the relevant mechanisms might be related to activating hsp20. This study provides new evidence for the mechanism of the ATR and may contribute to the theoretical basis of improving the acid tolerance of Lacticaseibacillus paracasei L9.
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Affiliation(s)
- Zhichao Shen
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China; (Z.S.); (L.L.); (Z.Z.); (J.L.); (L.C.)
- Key Laboratory of Functional Dairy, Department of Nutrition and Health, China Agricultural University, Beijing 100193, China;
| | - Li Lin
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China; (Z.S.); (L.L.); (Z.Z.); (J.L.); (L.C.)
| | - Zhengyuan Zhai
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China; (Z.S.); (L.L.); (Z.Z.); (J.L.); (L.C.)
| | - Jingjing Liang
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China; (Z.S.); (L.L.); (Z.Z.); (J.L.); (L.C.)
| | - Long Chen
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China; (Z.S.); (L.L.); (Z.Z.); (J.L.); (L.C.)
| | - Yanling Hao
- Key Laboratory of Functional Dairy, Department of Nutrition and Health, China Agricultural University, Beijing 100193, China;
| | - Liang Zhao
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China; (Z.S.); (L.L.); (Z.Z.); (J.L.); (L.C.)
- Key Laboratory of Functional Dairy, Department of Nutrition and Health, China Agricultural University, Beijing 100193, China;
- Research Center for Probiotics, China Agricultural University, Sanhe 065200, China
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Cao W, Aubert J, Maillard MB, Boissel F, Leduc A, Thomas JL, Deutsch SM, Camier B, Kerjouh A, Parayre S, Harel-Oger M, Garric G, Thierry A, Falentin H. Fine-Tuning of Process Parameters Modulates Specific Metabolic Bacterial Activities and Aroma Compound Production in Semi-Hard Cheese. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2021; 69:8511-8529. [PMID: 34283609 DOI: 10.1021/acs.jafc.1c01634] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The formation of cheese flavor mainly results from the production of volatile compounds by microorganisms. We investigated how fine-tuning cheese-making process parameters changed the cheese volatilome in a semi-hard cheese inoculated with Lactococcus (L.) lactis, Lactiplantibacillus (L.) plantarum, and Propionibacterium (P.) freudenreichii. A standard (Std) cheese was compared with three variants of technological itineraries: a shorter salting time (7 h vs 10 h, Salt7h), a shorter stirring time (15 min vs 30 min, Stir15min), or a higher ripening temperature (16 °C vs 13 °C, Rip16°C). Bacterial counts were similar in the four cheese types, except for a 1.4 log10 reduction of L. lactis counts in Rip16°C cheeses after 7 weeks of ripening. Compared to Std, Stir15min and Rip16°C increased propionibacterial activity, causing higher concentrations of acetic, succinic, and propanoic acids and lower levels of lactic acid. Rip16°C accelerated secondary proteolysis and volatile production. We thus demonstrated that fine-tuning process parameters could modulate the cheese volatilome by influencing specific bacterial metabolisms.
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Affiliation(s)
- Wenfan Cao
- UMR STLO, INRAE, Institut Agro, 35042 Rennes, France
| | - Julie Aubert
- Université Paris-Saclay, AgroParisTech, INRAE, MIA-Paris, 75005 Paris, France
| | | | | | - Arlette Leduc
- UMR STLO, INRAE, Institut Agro, 35042 Rennes, France
| | | | | | | | - Ali Kerjouh
- UMR STLO, INRAE, Institut Agro, 35042 Rennes, France
| | | | | | - Gilles Garric
- UMR STLO, INRAE, Institut Agro, 35042 Rennes, France
| | - Anne Thierry
- UMR STLO, INRAE, Institut Agro, 35042 Rennes, France
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Wilkinson MG, LaPointe G. Invited review: Starter lactic acid bacteria survival in cheese: New perspectives on cheese microbiology. J Dairy Sci 2020; 103:10963-10985. [DOI: 10.3168/jds.2020-18960] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Accepted: 07/21/2020] [Indexed: 11/19/2022]
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