Enhancing the underground community of microbes surrounding tea roots helps low-quality plants produce good tea – and high-quality plants produce even better tea.
Researchers at the Fujian Agriculture and Forest University in China found they could create communities of microscopic microorganisms that regulate nitrogen intake essential to theanine production. The amino acid, found only in tea, imparts a distinctive umami flavor and mouthfeel. Their study, published in February in the scientific journal Current Biology, attributes improved taste to a delicate balance known as nitrogen homeostasis.
Lead researcher Wenxin Tang writes, "The initial expectation for the synthetic microbial community derived from high-quality tea plant roots was to enhance the quality of low-quality tea plants.
"However, to our astonishment, we discovered that the synthetic microbial community not only enhances the low-quality tea plants but also significantly promotes certain high-quality tea varieties.”
"Furthermore, this effect is particularly pronounced in low-nitrogen soil conditions," adds researcher Tongda Xu. "Significant disparities in microbial communities, particularly nitrogen metabolism-related microorganisms, were identified in the roots of tea plants with varying qualities through microbiomics.”
Science Daily reports that by analyzing microbial populations in the roots of various tea plants across seasons, researchers developed a synthetic microbial community as a “custom-built team working together towards a common goal. In this case, the goal is to mimic the beneficial microbial environment of high-theanine-producing tea plants.”
Microbes that affect ammonia uptake for boosting theanine levels were assembled into a Synthetic Community called SynCom. The combination resembled the naturally occurring biome of Wuyi Rougui, which is high in theanine. When they applied SynCom to tea roots, the resulting tea improved. Tea consumes large quantities of nitrogen, which has tripled in price in recent years. Regulating intake more efficiently could enable farmers to reduce the amount applied.
Anirban Mahapatra, writing in the Hindustan Times, notes that “tea producers who adopt microbial management techniques to improve tea quality would be able to differentiate their products to open a whole new segment of the premium tea market.
Wei Xin, Jianming Zhang, Yongdong Yu, Yunhe Tian, Hao Li, Xiaolu Chen, Wei Li, Yanlin Liu, Ting Lu, Biyun He, Yan Xiong, Zhenbiao Yang, Tongda Xu, Wenxin Tang. Root microbiota of tea plants regulate nitrogen homeostasis and theanine synthesis to influence tea quality. Current Biology, 2024; DOI: 10.1016/j.cub.2024.01.044