We first find Xanthomonas campestris N. K-01 which don't produce xanthan at 28℃ cansynthesize and secrete the xanthan under low temperature (4℃). Little string is the most minute unit of the secreted under low temperature. Many little strings ecreted by bacterium cell extend to form a wider xanthan fiber. When depart from cell, xanthan fiber either twine to form double helix of bundle together. They are both advanced structures of the xanthan strings. Xanthan secreted under 4℃ has the same chemical composition and structure as that under 28℃, but lower moleculer weight and lower pyruvate content.

When growing and metabolizing through carbon resources of hydrocarbon, Pseudomonas 23-1 produces acidicacid and gas. The amount of acidic acid is 0. 015mol/L The output of gas,which thd main composition is CO2 and CH4, is 20ml/L. The organic acid and gas is the important reasons of decreasing the viscosity, enhancing the flow and improving the product of oil.

Pseudomonas 23-1 Can metabolize hydrocarbon to produce the surfactant which is glycolipid outside the cell. The glycolipid, whose content is 1.25g / L, is composed of rhamnose and tencarbon fatry acid. It's critical micella concentration is 200g/L. It has the good ability to emulsify the oil. The main reason of improving the product of oil, decreasing the viscosity and enhancing the flow of oil is the effect of surfastant-glycolipid.

When growing and metabolizing through carbon resources of hydrocarbon, Pseudomonas 23 1 produces acidicacid and gas. The amount of acidic acid is 0.015mol/L The output of gas,which thd main composition is CO 2 and CH 4, is 20ml/L. The organic acid and gas is the important reasons of decreasing the viscosity, enhancing the flow and improving the product of oil.