Glucose metabolism of lactic acid bacteria changed by quinone-mediated extracellular electron transfer.
It can be expected that extracellular electron transfer to regenerate NAD+ changes the glucose metabolism of the homofermentative lactic acid bacteria. In this work, the glucose metabolism of Lactobacillusplantarum and Lactococcus lactis was examined in resting cells with 2-amino-3-carboxy-1,4-naphthoquinone (ACNQ) as the electron transfer mediator and ferricyanide (Fe(CN)6(3-)) as the extracellular electron acceptor. NADH in the cells was oxidized by ACNQ with the aid of diaphorase, and the reduced ACNQ was reoxidized with Fe(CN)6(3-). The extracellular electron transfer system promoted the generation of pyruvate, acetate, and acetoin from glucose, and restricted lactate production. Diaphorase activity increased when cultivation was aerobic, and this increased the concentrations of pyruvate, acetate, and acetoin relative to the concentration of lactate to increase in the presence of ACNQ and Fe(CN)6(3-)
Yamazaki
Shin-ichi
S
Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo, Kyoto 606-8502, Japan.
Kaneko
Tsutomu
T
Taketomo
Naoki
N
Kano
Kenji
K
Ikeda
Tokuji
T
D000332:Aerobiosis; D000693:Anaerobiosis; D016227:Benzoquinones / Q000494:pharmacology*; D001692:Biological Transport; D003470:Culture Media; D004579:Electron Transport / Q000187:drug effects*; D005110:Extracellular Space / Q000187:drug effects / Q000378:metabolism; D005947:Glucose / Q000378:metabolism*; D019344:Lactic Acid / Q000378:metabolism*; D007778:Lactobacillus / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D013294:Lactococcus lactis / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D009243:NAD / Q000378:metabolism; D009285:Naphthoquinones / Q000494:pharmacology; D010084:Oxidation-Reduction; D011424:Propionibacterium / Q000254:growth & development / Q000378:metabolism
C108806:2-amino-3-carboxy-1,4-naphthoquinone; D016227:Benzoquinones; D003470:Culture Media; D009285:Naphthoquinones; D009243:NAD; D019344:Lactic Acid; C004532:quinone; D005947:Glucose