In this work, the secretome of the aerobic soil bacterium Sorangium cellulosum So ce56 was studied and the main hemicellulases for the degradation of arabinoxylan, avicel, wheat straw and oat spelts xylan were determined. For this purpose, bacterial cultures were set in triplicate for each substrate as well as for the basic medium CNS, which contained no lignocellulose substrate. Samples from the supernatants were taken after 5, 10 and 15 days of cultivation. After LC-MS/MS analysis, the secreted hemicellulases were identified and relatively quantified.