Deciphering the microbiome shift during fermentation of medicinal plants

Area of Science:

• Microbiology
• Plant Science
• Gut Microbiome Research

Background:

• The human microbiome is crucial for health, with diet influencing gut flora.
• Fermented foods and lactic acid bacteria (LAB) offer a preventive strategy against gut dysbiosis.
• The ecology of LAB on plants, particularly medicinal plants, remains underexplored.

Purpose of the Study:

• To characterize the leaf microbiome of medicinal plants (Matricaria chamomilla and Calendula officinalis).
• To investigate microbial shifts, particularly LAB dynamics, during plant fermentation.
• To identify potential sources of biopreservative LAB in plant leaf ecosystems.

Main Methods:

• 16S rRNA gene profiling was used to analyze leaf microbiomes.
• Samples from M. chamomilla and C. officinalis were collected over a six-week fermentation period.
• Phyllosphere and endosphere microbiomes were compared between unfermented and fermented states.

Main Results:

• Unfermented plants showed distinct phyllosphere and similar endosphere microbiomes.
• Fermentation significantly altered microbial communities, enhancing LAB presence without dominance.
• Enterococcaceae was the dominant LAB family; specific LAB families varied between M. chamomilla and C. officinalis.
• Plant and habitat specificity of natural leaf microbiomes and indigenous LAB were observed.

Conclusions:

• Medicinal plant leaf microbiomes are plant- and habitat-specific.
• Fermentation induces significant shifts in these microbiomes, increasing LAB populations.
• Leaf surfaces and endospheres are valuable sources of biopreservative LAB for food applications.