Abstract: Taking the lactic acid bacteria medium supplemented with purified water as a control,the protein content of the lactic acid bacteria medium supplemented with Gastrodia elata Blume extract at different fermentation time periods was determined.The Coomassie brilliant blue G-250 staining method was used to determine the protein content at the wavelength of 595 nm.The initial protein content of the medium with Gastrodia elata Blume extract was 18371.78 µg/mL,the minimum protein content was 446.24 µg/mL,the appearance time was 360 min,the protein degradation amount was 17925.54 µg/mL,and the conversion rate of protein was 97.56%;The initial protein content of CK group was 15803.75 µg/mL,the minimum protein content was 451.73 µg/mL,the appearance time was 420 min,the protein degradation amount was 15352.02 µg/mL,andthe conversion rate of protein was 97.14%.The analysis of variance showed that F = 30.8896 and F> F0.01,indicating that the difference was extremely significant （α=0.01）.Gastrodia elata Blume can promote the degradation of protein during the fermentation of lactic acid bacteria.

Key words: lactic acid bacteria, L.bulgaricus, S.thermophiles, gastrodia elata blume, protein content