on nutrient agar plate ph 8 na purchased nutrient agar from difco company and potato dextrose agar plate ph 8 pda purchased potato dextrose agar from difco company respectively next the plates are placed in the incubators under 30 u00b0 c and 50 u00b0 c for 24 hours and 48 hours respectively single colonies grown on plates are picked and isolated for obtaining the microorganism strains the number of microorganisms isolated from the rice straws and the livestock excrements having the decomposition ability is more than 200 strains finally the microorganisms are identified by the gram stain it is found that most of the microorganisms are gram positive bacteria the isolated microorganisms are further selected by the following steps for selecting the microorganism strains having the decomposition ability for rice straws 1 19 strains of the isolated strains named pmbp m1 pmbp m2 pmbp m3 pmbp m4 pmbp m5 pmbp m6 pmbp m7 pmbp o1 pmbp o2 pmbp o3 pmbp o4 pmbp e1 pmbp e2 pmbp e3 pmbp e4 pmbp h1 pmbp h2 pmbp h3 and pmbp h4 as shown in table 1 are divided into 9 strains groups including pmbp i pmbp ii pmbp iii pmbp iv pmbp v pmbp vi pmbp o pmbp e and pmbp h please refer to table 1 which shows the bacterial strains of different strain groups and the characteristics thereof 2 the strains groups are cultured with na plates respectively and then a suspension of microorganism is prepared at the concentration of 10 8 cfu ml 3 100 ml of solution containing.