Introduction: The use of  synthetic plstics has led to solid waste management problem and secondary problems such as global warming. In response to these issues, use of biodegradable polimers such as polyhydroxy butyrate (BHP) is suitable. The aim of this research was to evaluate maximum production of BHP and cell biomass in different growth condition as temperature, carbon source, incubation time and shaker speed.
 
Materials & methods: To evaluate BHP production, a total of 10 bacteria species isolated from soil contaminated to sewage in Ilam milk maufactory were tested for exictance of BHP using soudan black staining. Among all isolates, only one bacillus species had BHP. This species was diagnosed as bacillus cereus using biochemical tests and PCR reaction by using universal primer. The evaluation of BHP production has been carried out using GC-Mass and FTIR apparatues, and for maximum production of BHP and cell biomass, the effects of differences  growth inducer factors such as  temperature, carbon sources, shaking(aeration) and incubation time were tested.
 
Findings: In this survey we found that, the optimum condition for maximum production of PHB and biomas was incubation at 37˚C for 72h and shaking in 150rpm/min, uses of glucose as carbon source, and the ratres of PHB and biomass production were 0.188g/lit, 0.058g/lit respectivlly. Regarding GC-Mass results, the average of PHB production was 30%.
  
Discussion & Conclusions:  Using cheap sources of carbon, one can enhance production of this biopolymer  in the  industerial scale  for replacement of synthetic plastic to prvent bioenvironmental contamination.