Effects of edd and pgi disruptions on inosine accumulation in Escherichia coli.
Using an inosine-producing mutant of Escherichia coli, the contributions of the central carbon metabolism for overproducing inosine were investigated. Sodium gluconate instead of glucose was tested as a carbon source to increase the supply of ribose-5-phosphate through the oxidative pentose phosphate pathway. The edd (6-phosphogluconate dehydrase gene)-disrupted mutant accumulated 2.5 g/l of inosine from 48 g/l of sodium gluconate, compared with 1.4 g/l of inosine in the edd wild strain. The rpe (ribulose phosphate 3-epimerase gene)-disrupted mutant resulted in low cell growth and low inosine production on glucose and on gluconate. The disruption of pgi (glucose-6-phosphate isomerase gene) was effective for increasing the accumulation of inosine from glucose but resulted in low cell growth. The pgi-disrupted mutant accumulated 3.7 g/l of inosine from 40 g/l of glucose when 8 g/l of yeast extract was added to the medium. Furthermore, to improve effective utilization of adenine, the yicP (adenine deaminase gene)-disrupted mutant was evaluated. It showed higher inosine accumulation, of 3.7 g/l, than that of 2.8 g/l in the yicP wild strain when 4 g/l of yeast extract was added to the medium.
Shimaoka
Megumi
M
Fermentation and Biotechnology Laboratories, Ajinomoto Co. Inc., 1-1 Suzuki-cho, Kawasaki-ku, Kawasaki-shi, Kanagawa 210-8681, Japan.
Kawasaki
Hisashi
H
Takenaka
Yasuhiro
Y
Kurahashi
Osamu
O
Matsui
Hiroshi
H
D000225:Adenine / Q000494:pharmacology; D000619:Aminohydrolases / Q000235:genetics / Q000378:metabolism; D002455:Cell Division / Q000187:drug effects / Q000235:genetics; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism; D005942:Gluconates / Q000494:pharmacology; D005947:Glucose / Q000494:pharmacology; D005956:Glucose-6-Phosphate Isomerase / Q000235:genetics* / Q000378:metabolism; D005954:Glucosephosphate Dehydrogenase / Q000235:genetics / Q000378:metabolism; D006836:Hydro-Lyases / Q000235:genetics* / Q000378:metabolism; D007288:Inosine / Q000096:biosynthesis*; D009154:Mutation; D013997:Time Factors
D005942:Gluconates; D007288:Inosine; D005954:Glucosephosphate Dehydrogenase; D000619:Aminohydrolases; C018774:adenine deaminase; D006836:Hydro-Lyases; C022362:phosphogluconate dehydratase; D005956:Glucose-6-Phosphate Isomerase; D005947:Glucose; D000225:Adenine