Journal of Microbiology

Culture conditions affecting the molecular weight distribution of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) synthesized by alcaligenaes sp. SH-69: Yoon, Joo Seok , Park, Sang Kyu , Kim, Young Baek , Maeng, Hack Young , Rhee, Young Ha; J. Microbiol. 1996;34(3):279-283.

Abstract: The weight average molecular weight of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) synthesized by Alcaligenes sp. SH-69 was altered between 3.2 × 10^5 and 1.1 × 10^6 depending upon various culture conditions. It appeared that culture conditions favorable for the efficient production of copolyesters promoted the formation of higher molecular weight copolyesters. Polydispersity indices of isolated copolyesters were in the range of 1.5 to 2.5.

Partial purification and characterization of β-ketothiolase from Alcaligenes sp. SH-69: Oh, Deok Hwan , Chung, Chung Wook , Kim, Jeong Yoon , Rhee, Young Ha; J. Microbiol. 1997;35(4):360-364.

Abstract: A β-ketothiolase was purified 180-fold from the cell extracts of Alcaligenes sp. SH-69 by a series of chromatography on DEAE-Dephadex A-50, Sephacryl S-200, and hydrozyapatitie columns, The optimum pH values of the partially purified enzyme were 7.5 for condensation reaction and 8.3 for thiolysis reaction. The K_m valued for acetoacetyl-CoA and free CoASH in the thiolusis in the condensation reaction was 0.70mM. The condensation reaction of the β-ketothiolase was inhibited even by low concentrations of free CoASH(K_I= 30.4 uM). Pretreatment of the enzyme with NADH and NADPH markedly inhibited the thiolysis reaction of the enzyme. The potent inhibition of the enzyme by sulfhydryl reagents suggests the involvement of cystein residue in the active site.

Search