Identifying membrane-bound quinoprotein glucose dehydrogenase from acetic acid bacteria that produce lactobionic and cellobionic acids.
Biosci Biotechnol Biochem
; 83(6): 1171-1179, 2019 Jun.
Article
em En
| MEDLINE
| ID: mdl-30777491
ABSTRACT
Acetic acid bacteria are used in the commercial production of lactobionic acid (LacA). However, the lactose-oxidizing enzyme of these bacteria remains unidentified. Lactose-oxidizing activity has been detected in bacterial membrane fractions and is strongly inhibited by d-glucose, suggesting that the enzyme was a membrane-bound quinoprotein glucose dehydrogenase, but these dehydrogenases have been reported to be incapable of oxidizing lactose. Thus, we generated m-GDH-overexpressing and -deficient strains of Komagataeibacter medellinensis NBRC3288 and investigated their lactose-oxidizing activities. Whereas the overexpressing variants produced ~2-5-fold higher amounts of LacA than the wild-type strains, the deficient variant produced no LacA or d-gluconic acid. Our results indicate that the lactose-oxidizing enzyme from acetic acid bacteria is membrane-bound quinoprotein glucose dehydrogenase. Abbreviations LacA lactobionic acid; AAB acetic acid bacterium; m-GDH membrane-bound quinoprotein glucose dehydrogenase; DCIP 2,6-dichlorophenolindophenol; HPAEC-PAD high-performance anion-exchange chromatography with pulsed amperometric detection.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Acetobacteraceae
/
Dissacarídeos
/
Glucose Desidrogenase
Idioma:
En
Ano de publicação:
2019
Tipo de documento:
Article