Abstract
To investigate the characters of Agrobacterium sp. KY-8589(an ethionine-resistant mutant) showing excellent potential for coenzyme Q10 (CoQ10) production, two kinds of agar media were used for colony isolation. Marked differences in the form and color of colonies were seen between the agar media of glucose-yeast-bouillon (A) and glucose-yeast (B). Especially, the rough-white (Rw) and smooth-light yellow (Sy) types were isolated on agar mediumB. The effects of the two types purified morphologically on CoQ10 fermentation were further investigated. Although both types have the same ethionine-resistance, significant differences in growth, broth viscosity and CoQ10 production were found between them. The amount of CoQ10 accumulated in the broth by Rwshowed an increment of 25%compared with that by Sy. In this case, the intracellular contents of CoQ10 for Rw and Sy were 4.1 and 2.8mg/g-cell, respectively. In addition, the reduced production with repeated use of KY-8589was shown to be due to the decrease in Rw/Syratio, which was caused by the rapid growth of Sy.
