The study found that tea waste is an environmentally friendly and nutrient-rich substrate for oyster mushrooms. This method significantly outperforms grain fillers like wheat bran or rice bran, which are typically used, but have drawbacks such as potential health risks and lower biological efficiency. Nutritional benefits The use of tea waste as a substrate not only yields higher mushroom growth rates but also results in oyster mushrooms with higher levels of essential amino acids and micronutrients compared to those grown on grain fillers.