I am culturing Ralstonia eutropha in nutrient broth till stationary phase, 60h. Cell pellet lyophilised and then the PHA extraction was tried by two method: CHCl3-60oC for 36h and CHCl3/NaOCl dispersion at 37oC for 90minfollowed by precipitation using 5x ice cold methanol.

But the % accumulation am getting is much lower than reported. The cell dry weight is coming around 3g/L (from 100ml culture). Initially I was using 0.22 μm nylon filter to filter chloroform extract. I couldn't still find why % accumulation is so low (1%).