Abstract: To study the differential proteome expression of an efficient bioflocculant-producing strain A9 cultured respectively in ordinary broth medium, dextrose medium and mannose medium, proteins were compared and analyzed by twodimensional electrophoresis (2-DE) and identified by mass spectrometry. The results showed significant differences of proteome expression among test groups cultured with different carbon sources. There were 54 differential proteins identified by mass spectrometry, including dihydrolipoyl dehydrogenase, triosephosphate isomerase, fructose-1,6-bisphosphatase, glyceraldehyde-3-phosphate dehydrogenase, phosphoglycerate kinase, aconitase, phosphate acyltransferase, peptidylprolylcistrans isomerase, elongation factor G, etc, which were mainly related to synthesis and metabolism of carbohydrates, transportation and metabolism of lipids, posttranslational modification of proteins, and structure and generation of ribosomes. The proteomic research of bioflocculant-producing strain A9 in different media would provide theoretical basis for optimizing culture conditions of strain A9.

Key words: watershed, planting system, emergy analysis, Loess Plateau.