Different C:N ratios were maintained using the best carbon and nitrogen sources in sucrose/yeast extract as well as their effects on PHB production were studied. The C:N ratios were adjusted to 15:1, 20:1 and 25:1 using sucrose and ammonium sulphate as C and N sources for B. cereus. The data are presented in Table 9 showed that, B. cereus was found to be significantly higher PHB producer mean where the PHB of 4.6 g/L culture, respectively