Effects of Amino Acid Addition on Molar Fraction of 3-Hydroxyvalerate in Copolyester of 3-Hydroxybutyrate and 3-Hydroxyvalerate Synthesized by Alcaligenes sp. SH-69

다국어 초록 (Multilingual Abstract)

Addition of the amino acids threonine, isoleucine, and valine into culture medium greatly increased the molar fraction of 3-hydroxyvalerate(3HV) in the copolyester of 3-hydroxybutyrate (3HB) and 3HV produced by Alcaligenes sp. SH-69. In shake flask cultures, addition of threonine, isoleucine, or valine into culture mediumresulted in 53.0, 40.7, or 14.8 mol% 3HV in the copolyester, respectively. The 3HV content in the copolyester was 14 mol% and 27 mol% in jar fermentor cultures containing 10 mM and 20 mM threonine, respectively. Similar molar freactions of 3HV(11-14 mol%) in the copolyester were obtained in experiments carried out with culture media containing 10 mM isoleucine or valine. The 3HV content in the copolyester increased as aminoacid concentration increased. Addition of the amino acids into culture medium at different culture times revealed that final 3HV contents were ismilar irrespective of addition time except for the case when glucose was depleted.