Average 3H4MV fraction in PHA synthesized by R. eutropha PHB-
4 expressing phaC1
(parent strain) and leucine analog resistant mutants (mutant strains) using MS plus fructose (20 g/L) medium. Number of repeated culture of the parent strain and number of analyzed colonies were 20 and 440, respectively. 3H4MV fractions were determined by HPLC analysis. Statistical analyses were performed with Student's t-test (*P < 0.01).