P(3HB-co-4HB) was produced by flask and fed-batch
cultures of R. eutropha ATCC 17699 from fructose and
-butyrolactone as carbon source. High concentrations of
fructose and -butyrolactone inhibited cell growth, suggesting
feeding rate of fructose and -butyrolactone should
be controlled in fed-batch fermentation. Acetate as well
as propionate was a stimulator of 4HB unit incorporation
into PHA copolymer, which was our new finding.
By changing the ratio of -butyrolactone to fructose in
feeding solution, 4HB fraction in the copolymer was controlled.
Enough amounts of P(3HB-co-4HB) samples with
various 4HB fractions from 0 to 50 mol% could be produced
for testing purposes through flask and fed-batch
cultures.