Results and Discussion
Screening of PHA Biolyester Accumulating Bacteria: Table II summarized the types of
biopolyesters synthesized from three bacterial cultures under varied conditions including pH,
temperature, and aeration. Negligible growth of all types of bacteria was observed in any cultural
conditions at 40°C (data not shown). The results showed that at pH 7, 30°C, and oxic condition all
bacteria are able to accumulate polyester, which was later confirmed its structure as P(3HB-co
4HV) by IH-NMR spectrum. At this condition A. eutrophusyielded maximal dried cell weight (DCW)
compared to A. faeca/is and P. o/eovo/ans (Fig. 1). Meanwhile cultivation at pH 5 and 30°C
regardless of aeration conditions appeared to be not proper conditions for A. faeca/is and P.