Succession of Bacterial and Fungal Communities during Fermentation of Medicinal Plants

Abstract

The fermentation of medicinal plants has been studied very little, as compared to the fermentation of food and beverages. One approach applies fermentation by single bacterial or fungal strains and targets the production of specific compounds or preservation of the fermented material. Spontaneous fermentation by an autochthonous starter community may lead to a more diverse blend of fermentation products because co-occurring microbes may activate the biosynthetic potentials and formation of compounds not produced in single strain approaches. We applied the community approach and studied the fermentation of four medicinal plants (Achillea millefolium, Taraxacum officinale, Mercurialis perennis, and Euphrasia officinalis), according to a standardized pharmaceutical fermentation method. It is based on the spontaneous fermentation by plant-specific bacterial and fungal communities under a distinct temperature regime, with a recurrent cooling during the first week and further fermentation for at least six months. The results revealed both general and plant-specific patterns in the composition and succession of microbial communities during fermentation. Lactic acid bacteria increasingly dominated in all preparations, whereas the fungal communities retained more plant-specific features. Three distinct fermentation phases with characteristic bacterial communities were identified, i.e., early, middle, and late phases. Co-occurrence network analyses revealed the plant-specific features of the microbial communities.

Chemical and Microbial Characterization of Fermented Forest Litters Used as Biofertilizers

“…These results are consistent with other studies, although performed on different plant materials. For example, the richness and effective number of bacterial and fungal genera during medicinal plants tend to decrease during fermentation [ 36 ]. Further investigation using high throughput sequencing could be performed in order to identify the most dominant species in the FFLs.…”

Effects of Dendrobium officinale on the Quality of Rice Wine Fermented Separately by Saccharomyces cerevisiae and Wickerhamomyces anomalus: Physicochemical Indices, Volatile Compounds and Nonvolatile Metabolites

“…Synergistic effects can occur between medicinal plants and microorganisms, as nutrients present in medicinal plants help microorganisms to divide and grow, further promoting biotransformation [4]. In recent years, medicinal foods have also been used for fermentation [5], and some medicinal fermentation products have been shown to have activities such as antioxidant and antibacterial effects [6], protection against cell damage [7] and anticytotoxic effects [8].…”