Abstract: In order to explore the effects of botanical proliferative substrates on the biomass of Lactobacillus acidophilus CICC6005,and to analyze the changes of protein expression level in fermented cells,orthogonal optimization was applied to determine the biomass of TJA medium by adding various proliferative substrates in this study. The intracellular and extracellular proteins were purified and identified by SDS-PAGE gel electrophoresis. The results showed that,the optimum concentration of proliferative substrates from three plant sources was 5% tomato juice,3% potato juice,2% apple juice,and the number of viable bacteria in fermentation broth was 2.31×10¹⁰ CFU/mL. The order of factors affecting the growth of L. acidophilus CICC6005 strain was tomato juice,potato juice and apple juice. The maps of all proteins expressed in fermentation broth showed that L. acidophilus CICC6005 strain had a significant increase in the number of proteins expressed under the nutritional conditions. According to the standard curve,the molecular weight of each peak was 59 and 17 ku,and the molecular weight of extracellular protein was 66 and 35 ku,with the expression quantities of 2.144,0.744,2.394 and 4.644 mg/mL,respectively. The maps of expression of all protein in the fermentation broth showed that the number of protein expressed in L. acidophilus CICC6005 strain increased obviously under the nutritional conditions. According to the standard curve,the molecular weight of each peak was 59 and 17 ku,and the molecular weight of extracellular protein was 66 and 35 ku,the expression quantities were 2.144,0.744,2.394 and 4.644 mg/mL respectively. In conclusion,on the TJA basic medium,the suitable concentration of plant source proliferative substrates played a certain role in promoting the proliferation of L. acidophilus CICC6005 strain and protein expression level. At the same time, two major proteins expressed by the strain were purified and identified,which was of scientific and practical significance for further analysis and identification of its probiotic function.