Excess of threonine compared with serine promotes threonine aldolase activity in Lactococcus lactis IL1403.
Microbiology (Reading)
; 161(Pt 5): 1073-1080, 2015 May.
Article
em En
| MEDLINE
| ID: mdl-25743155
Lactococcus lactis is an important lactic acid starter for food production as well as a cell factory for production of food grade additives, among which natural flavour production is one of the main interests of food producers. Flavour production is associated with the degradation of amino acids and comprehensive studies are required to elucidate mechanisms behind these pathways. In this study using chemically defined medium, labelled substrate and steady-state cultivation, new data for the catabolism of threonine in Lc. lactis have been obtained. The biosynthesis of glycine in this organism is associated with the catabolic pathways of glucose and serine. Nevertheless, if threonine concentration in the growth environment exceeds that of serine, threonine becomes the main source for glycine biosynthesis and the utilization of serine decreases. Also, the conversion of threonine to glycine was initiated by a threonine aldolase and this was the principal pathway used for threonine degradation. As in Streptococcus thermophilus, serine hydroxymethyltransferase in Lc. lactis may possess a secondary activity as threonine aldolase. Other catabolic pathways of threonine (e.g. threonine dehydrogenase and threonine dehydratase) were not detected.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Serina
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Glicina Hidroximetiltransferase
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Treonina
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Lactococcus lactis
Idioma:
En
Revista:
Microbiology (Reading)
Assunto da revista:
MICROBIOLOGIA
Ano de publicação:
2015
Tipo de documento:
Article
País de afiliação:
Estônia