Erucic acid utilization by Lactobacillus johnsonii N6.2.

Area of Science:

• Microbiology
• Nutritional Science
• Molecular Biology

Background:

• Erucic acid (EA), a fatty acid (FA) abundant in rapeseed and mustard oil, is linked to increased lactic acid bacteria (LAB) counts.
• Lactobacillus johnsonii N6.2 and other LAB species can effectively metabolize EA as a primary FA source.

Purpose of the Study:

• To investigate the metabolic pathways and genetic regulation of EA utilization by *L. johnsonii*.
• To characterize the changes in FA profiles of *L. johnsonii* when grown with EA.
• To identify genes and pathways involved in EA assimilation and lipid synthesis.

Main Methods:

• Culturing *L. johnsonii* N6.2 with EA as the sole FA source.
• Global transcriptomics to analyze gene expression changes.
• Liquid chromatography-mass spectrometry (LC-MS) to determine FA profiles.

Main Results:

• EA assimilation in *L. johnsonii* involves the FakA/FakB and plsX/plsY/plsC pathways for phosphatidic acid synthesis.
• Upregulation of *fakB2*, *fakB4*, *plsY2*, *plsC2*, and *plsC4* genes observed in EA-grown cells.
• Rapid incorporation of EA and synthesis of omega-9 monounsaturated fatty acids, including nervonic and gondoic acids, were confirmed.

Conclusions:

• *L. johnsonii* possesses specific mechanisms for efficient EA uptake and metabolism.
• EA serves as a precursor for synthesizing valuable long-chain fatty acids with potential health benefits.
• This research elucidates the molecular basis of LAB adaptation to dietary fatty acids.