| 摘要 |
Low pyruvate xanthan gum comprising 0.1-1% by weight pyruvate (FCC Method) has useful properties for secondary oil recovery. It is produced by aerobically fermenting an organism of the genus Xanthomonas in a broth comprising: 1) a chemically defined simple salts medium comprising sources of nitrogen, sulphur, potassium, phosphorus, magnesium, calcium, and (optionally) iron, said simple salts medium being substantially free of cobalt, copper, manganese, zinc and boron; 2) an assimilable carbon source, and 3) a complex organic material which is a nitrogen source. |
