Effect of aqueous extracts from natural sweetener-producing plants on the growth and antagonistic and phytotoxic activity of soil microorganisms
Abstract
This study assessed the effect of aqueous extracts from natural sweetener-producing plants — Stevia rebaudiana (stevia) leaves, Glycyrrhiza glabra (licorice) roots/rhizomes, and Helianthus tuberosus (Jerusalem artichoke) tubers — on the growth, antagonistic, and phytotoxic activities of soil microorganisms, including several bacterial species, micromycetes, and the green alga Tetracystis sp. The addition of aqueous extracts to the nutrient medium stimulated colony growth in all tested micromycetes and the bacterium Azotobacter chroococcum. The highest stimulatory effect was observed for extracts from stevia leaves and Jerusalem artichoke tubers. The antagonistic activity of the micromycete Trichoderma viride against potentially phytopathogenic fungi was enhanced during co-cultivation with aqueous extracts from all studied plants. The strongest phytotoxic effect was exerted by Aspergillus niger when grown on a medium supplemented with licorice root extract. Conversely, the lowest level of phytotoxicity was observed for Fusarium oxysporum cultivated with the addition of Jerusalem artichoke tuber extract. These findings indicate the selective and species-specific influence of aqueous extracts of the studied plants on the functional activity of the soil microbiome. This effect could be leveraged to develop biological agents aimed at optimizing cultivation conditions for natural sweetener-producing crops.
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References
Modern methods in allelopathic research. Methodical manual. (Editor in Chief: Corresponding Member of NAS of Ukraine, Professor Zaimenko N.V.) Kyiv : Publishing Lira-K, 2021. 200 p. (In Ukrainian)
Atlas R. M. (2010). Handbook of microbiological media (4th ed.). CRC Press. 2043 р.
Bischoff H. W., Bold H. C. (1963). Some soil algae from Enchanted Rock and related algal species (No. 6318). University of Texas Publication. 95 р.
Chakma A., Hossain M. A., Rahman M. M., Islam M. T., Uddin M. J., Rahman M. S. (2023). Effects of extraction techniques on antioxidant and antibacterial activity of stevia (Stevia rebaudiana Bertoni) leaf extracts. Food Chemistry Advances, 3, 100494. https://doi.org/10.1016/j.focha.2023.100494
Chen C., Zhong C., Gao X., Tan C., Bai H., Ning K. (2022). Glycyrrhiza uralensis Fisch. root-associated microbiota: The multifaceted hubs associated with environmental factors, growth status and accumulation of secondary metabolites. Environmental Microbiome, 17(1), 23. https://doi.org/10.1186/s40793-022-00418-0
Chen R. Y., Yu D., Wang Y. Q., Li C. X., Zhang R. Q., Wang X. Y., Chen H. S. (2024). The state-of-the-art antibacterial activities of glycyrrhizin: A comprehensive review. Microorganisms, 12(6), 1155. https://doi.org/10.3390/microorganisms12061155
Flanagan P. W. (1978). Microbial ecology and decomposition in Arctic tundra and subarctic taiga ecosystem. In Microbial ecology. Berlin. Р. 161-168.
Guzmán-Guzmán P., Porras-Troncoso M. D., Olmedo-Monfil V., Herrera-Estrella, A. (2023). Trichoderma species: Our best fungal allies in the biocontrol of plant diseases—A review. Plants, 12(3), 432. https://doi.org/10.3390/plants12030432
Liu Y., Zhang H., Chen J., Li W., Wang Y., Zhang Y. (2022). Regulation of soil micro-foodwebs to root secondary metabolites in cultivated and wild licorice plants. Science of the Total Environment, 828, 154302. https://doi.org/10.1016/j.scitotenv.2022.154302
Madeo L., Panzera Y., Bruno L., Sicari V. (2026). Licorice (Glycyrrhiza glabra): Botanical aspects, multisectoral applications, and valorization of industrial waste for the recovery of natural fiber in a circular economy perspective. Fibers, 14(1), 14. https://doi.org/10.3390/fib14010014
Muñoz-Labrador A., Hernandez-Hernandez O., Moreno F. J. (2024). A review of the state of sweeteners science: The natural versus artificial non-caloric sweeteners debate. Stevia rebaudiana and Siraitia grosvenorii into the spotlight. Critical Reviews in Biotechnology, 44(6), 1080–1102. https://doi.org/10.1080/07388551.2023.2254929
Nongthombam J., Devi N. A., Singh P. K., Devi H. S. (2021). Azotobacter: A complete review. Bulletin of Environment, Pharmacology and Life Sciences, 10(6), 72–79.
Pate, S., Navale A. (2024). The natural sweetener stevia: An updated review on its phytochemistry, health benefits, and anti-diabetic study. Current Diabetes Reviews, 20(2), 26–36. https://doi.org/10.2174/1573399819666230501210803
Peteliuk V., Rybchuk L., Bayliak M., Storey K. B., Lushchak O. (2021). Natural sweetener Stevia rebaudiana: Functionalities, health benefits and potential risks. EXCLI Journal, 20, 1412–1430. https://doi.org/10.17179/excli2021-4211
Qu P., Wang B., Qi M., Lin R., Chen H., Xie C., Liu Q., Zhang G., Ge Y. (2024). Medicinal plant root exudate metabolites shape the rhizosphere microbiota. International Journal of Molecular Sciences, 25(14), 7786
Reischke S., Rousk J., Bååth E. (2014). The effects of glucose loading rates on bacterial and fungal growth in soil. Soil Biology and Biochemistry, 70, 88–95. https://doi.org/10.1016/j.soilbio.2013.12.011
Ren X., Zhu Y., Xie C., Li X., Wen L., Qin L. (2017). Allelochemicals from rhizosphere soils of Glycyrrhiza uralensis Fisch: Discovery of the autotoxic compounds of a traditional herbal medicine. Industrial Crops and Products, 97, 302–307. https://doi.org/10.1016/j.indcrop.2016.12.035
Shahid M., Khan M. S. (2022). Tolerance of pesticides and antibiotics among beneficial soil microbes recovered from contaminated rhizosphere of edible crops. Current Research in Microbial Sciences, 3, 100091. https://doi.org/10.1016/j.crmicr.2021.100091
Shao T., Zhang Z., Liu T., Li Y., Wang X., Chen, M. (2025). Rhizosphere remediation of saline-alkali soils by Helianthus tuberosus: Linking microbial-metabolite synergies to carbon sequestration. Science of the Total Environment, 1002, 180533. https://doi.org/10.1016/j.scitotenv.2025.180533
Showkat M. M., Falck-Ytter A. B., Strætkvern K. O. (2019). Phenolic acids in Jerusalem artichoke (Helianthus tuberosus L.): Plant organ dependent antioxidant activity and optimized extraction from leaves. Molecules, 24(18), 3296. https://doi.org/10.3390/molecules24183296
Sun Y., Li X., Wang C., Zhang H., Liu X., Zhao T. (2022). The recruitment of specific rhizospheric bacteria facilitates Stevia rebaudiana salvation under nitrogen and/or water deficit stresses. Industrial Crops and Products, 187, 115434. https://doi.org/10.1016/j.indcrop.2022.115434
Tapera R. F., Moyo P., Mukanganyama S., Mduluza T. (2024). Exploring the therapeutic potential, ethnomedicinal values, and phytochemistry of Helianthus tuberosus L.: A review. Pharmaceuticals, 17(12), 1672. https://doi.org/10.3390/ph17121672
Ullah I., Khan N., Ahmad S., Rahman U. U., Ali J. (2025). Unveiling the adaptation mechanisms of symbiotic microbial communities in Glycyrrhiza glabra under extreme environmental conditions. Journal of Applied Microbiology, 136(12), lxaf291. https://doi.org/10.3390/plants10122751
Wahab S., Annadurai S., Abullais S. S., Das G., Ahmad W., Ahmad, M. F., Kandasamy G., Vasudevan R., Amir M. (2021). Glycyrrhiza glabra (Licorice): A comprehensive review on its phytochemistry, biological activities, clinical evidence and toxicology. Plants, 10(12), 2751. https://doi.org/10.3390/plants10122751
Wang L., Zhang Y., Chen X., Liu H., Zhao Y., Li J. (2025). Stevia rebaudiana Bertoni as a sweet herbal medicine: Traditional uses, potential applications, and future development. Frontiers in Pharmacology, 16, 1638147. https://doi.org/10.3389/fphar.2025.1638147
Xu X., Luo Q., Wei Q., Jiang S., Dong C., Faruque M. O., Hu X. (2024). Sandy loam soil maintains better physicochemical parameters and more abundant beneficial microbiomes than clay soil in Stevia rebaudiana cultivation. PeerJ, 12, e18010. https://doi.org/10.7717/peerj.18010
Xu X., Luo Q., Wei Q., Jiang S., Dong C., Faruque M. O., Hu X. (2022). The deterioration of agronomical traits of the continuous cropping of stevia is associated with the dynamics of soil bacterial community. Frontiers in Microbiology, 13, 917000. https://doi.org/10.3389/fmicb.2022.917000
Yadav A. K., Singh S., Dhyani D., Ahuja P. S. (2011). A review on the improvement of stevia [Stevia rebaudiana (Bertoni)]. Canadian Journal of Plant Science, 91(1), 1–27. https://doi.org/10.4141/cjps10086
Yue Y., Shao T., Long X., He T., Gao X., Zhou Z., Liu Z. (2020). Microbiome structure and function in rhizosphere of Jerusalem artichoke grown in saline land. Science of the Total Environment, 724, 138259. https://doi.org/10.1016/j.scitotenv.2020.138259
Zhou X., Wang Z., Jia H., Li L., Wu F. (2017). Conversion from long-term cultivated wheat field to Jerusalem artichoke plantation changed soil fungal communities. Scientific Reports, 7(1), 41502. https://doi.org/10.1038/srep41502
Zhou X., Wang Z., Jia H., Li L., Wu F. (2018). Continuously monocropped Jerusalem artichoke changed soil bacterial community composition and ammonia-oxidizing and denitrifying bacteria abundances. Frontiers in Microbiology, 9, 705. https://doi.org/10.3389/fmicb.2018.00705
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