Strain DM-1 which was identified as Bacillus sp.was characterized to degrade crude oil and produce extra cellular polysaccharide at a high temperature.At the temperature of 55℃

strain DM-1 could emulsify and degrade crude oil anaerobically.This strain could unitize crude oil as the sole carbon source and the degradation rate was 61.51%.It also produced extra cellular polysaccharide (EPS) in special medium at a high temperature.High performance liquid chromatography (HPLC) analysis of the EPS revealed that it mainly consisted of mannose (91.87%)

glucose (7.95%) and galactose (0.18%).Carbon source and temperature were optimized and EPS yield could reach 1.7 g·L-1.Manual cores were used to simulate the actual environment in petroleum reservoirs and the results showed that strain DM-1 could increase the pressure in the core from 0.01 MPa to 0.40 MPa and permeability was reduced from 3.856 μm2 to 1.589 μm2.Oil recovery was increased by 3.9%.Environmental scanning electron microscopy (ESEM) technology was used to observe the microcosmic conditions in the cores.Strain DM-1 can be used in microbial enhanced oil recovery（MEOR）.