Abstract:To improve the utilization efficiency of organic solid wastes，strains which have excellent capacity of fluvic acid production and lignocellulose decomposition were screeded.7 thermoduric strains which grow well at 45℃were isolated from the deep litter system for dairy cattle breeding in Beijing suburbs.Evaluating by the production yield of fulvic acid and the decomposition ability to lignocellulose，strain DLS07 and strain DLS03 were screeded.Strain DLS07 had higher production yield of fulvic acid and decomposition ability to Cellulose and hemi cellulose than others.Strain DLS03 degraded lignin better than others.The fulvic acid fermentation of the mixed cultures of these two strains inoculated by 1∶1 were studied.The fulvic acid production of the mixed cultures reached 76.73 g/kg，which was 37%and 9%higher than that of strain DLS03 and DLS07.The degradation rate of cellulose，hemi cellulose and lignin by the mixed cultures were 32.87%，45.46%，44.55%respectively，higher than single strain.The result indicated the fermentation efficiency of the mixed cultures was superior to that of single strain.Based on 16SrDNA，the DLS03 was identified as Bacillus subtilis and DLS07 was Bacillus licheniformis.The mixed cultures of these two strains which exhibited excellent decomposition ability to lignocellulose and higher production yield of fluvic acid，had potential applications in the resource utilization of organic solid wastes.