关键词: 甘油脱水酶, 三磷酸腺苷(ATP), 3 丙二醇, 克氏肺炎杆菌, 甘油

Abstract: Biosynthesis of 1,3-propanediol (1,3-PD) attracted much attention recently. Glycerol dehydratase, the key enzyme of the biosynthesis of 1,3-PD from glycerol, tends to undergo mechanism-based inactivation by glycerol during catalysis, and the inactive dehydratase was rapidly reactivated in the presence of AdoCbl, ATP and Mg2+ (or Mn2+). In this paper, the effect of ATP on biosynthesis of 1,3-PD from glycerol by Klebsiella pneumoniae L1 was investigated. Although bacterium growth was inhibited with ATP addition in fermentation medium, the capability of 1,3-PD biosynthesis by K. pneumoniae cells per OD was increased. By addition of 0.6 0.8 g/L ATP, the reductive metabolism of glycerol was strengthened and the titer of 1,3-propanediol increased by 50 70 . The yield of 1,3-PD was also improved, especially in the latter phase of fermentation compared with a rapidly decreased yield in control experiment. For seeing about the simulative effect of ATP on 1,3-PD biosynthesis, rest K. pneumoniae cells were used in this work. It indicated that ATP could reactivate the inactive glycerol dehydratase effectively, and the activity of dehydratase would not decrease observably during repetitious reactivation. ATP was an important factor affecting the catalysis activity of glycerol dehydratase and even the biosynthesis of 1,3-PD from glycerol by K. pneumoniae. Keeping ATP in a higher concentration in the fermentation system was a logical approach to improve 1,3-PD biosynthesis.

Key words: glycerol dehydratase, ATP, 3-propanediol, Klebsiella pneumoniae, glycerol