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Lactobacillus paracasei A13 and High-Pressure Homogenization Stress Response
Lorenzo Siroli1, Giacomo Braschi1, Samantha Rossi1
1Department of Agricultural and Food Sciences, University of Bologna, p.zza Goidanich 60, 47521 Cesena, Italy.
Microorganisms
|April 5, 2020
Summary
Sub-lethal high-pressure homogenization enhances Lactobacillus paracasei A13 properties by modifying membrane fatty acids. Gene expression reveals immediate responses to stabilize membrane fluidity under pressure.
Area of Science:
- Microbiology
- Biochemistry
- Probiotics
Background:
- Probiotic lactobacilli require membrane adaptation to survive stress.
- High-pressure homogenization (HPH) can improve functional properties of probiotics.
- Membrane fatty acid composition is crucial for bacterial stress response.
Purpose of the Study:
- To investigate the link between membrane fatty acid changes and gene expression in Lactobacillus paracasei A13 under HPH.
- To understand the molecular mechanisms of Lactobacillus paracasei A13 adaptation to sub-lethal HPH treatments.
- To identify key genes involved in fatty acid biosynthesis in response to HPH.
Main Methods:
- Application of sub-lethal high-pressure homogenization treatments (150 and 200 MPa) to Lactobacillus paracasei A13.
- Analysis of changes in membrane fatty acid composition.
- Quantitative gene expression analysis of genes involved in fatty acid biosynthesis.
Main Results:
- Lactobacillus paracasei A13 adapted to HPH by altering membrane fluidity through fatty acid unsaturation and elongation.
- Gene expression analysis showed up-regulation of accA, accC, fabD, fabH, and fabZ at 150/200 MPa, and fabK, fabZ at 200 MPa.
- These gene expression changes represent an immediate response to maintain membrane fluidity.
Conclusions:
- Sub-lethal HPH treatments modulate fatty acid biosynthesis genes in Lactobacillus paracasei A13.
- This regulation is a key mechanism for stabilizing membrane fluidity under hyperbaric stress.
- Further research is needed on phospholipid and glycoprotein biosynthesis for a complete understanding of functional property enhancement.
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