Formate cross-feeding and cooperative metabolic interactions revealed by transcriptomics in co-cultures of acetogenic and amylolytic human colonic bacteria.
Environ Microbiol
; 21(1): 259-271, 2019 01.
Article
em En
| MEDLINE
| ID: mdl-30362296
ABSTRACT
Interspecies cross-feeding is a fundamental factor in anaerobic microbial communities. In the human colon, formate is produced by many bacterial species but is normally detected only at low concentrations. Ruminococcus bromii produces formate, ethanol and acetate in approximately equal molar proportions in pure culture on RUM-RS medium with 0.2% Novelose resistant starch (RS3) as energy source. Batch co-culturing on starch with the acetogen Blautia hydrogenotrophica however led to the disappearance of formate and increased levels of acetate, which is proposed to occur through the routing of formate via the Wood Ljungdahl pathway of B. hydrogenotrophica. We investigated these inter-species interactions further using RNAseq to examine gene expression in continuous co-cultures of R. bromii and B. hydrogenotrophica. Transcriptome analysis revealed upregulation of B. hydrogenotrophica genes involved in the Wood-Ljungdahl pathway and of a 10 gene cluster responsible for increased branched chain amino acid fermentation in the co-cultures. Cross-feeding between formate-producing species and acetogens may be a significant factor in short chain fatty acid formation in the colon contributing to high rates of acetate production. Transcriptome analysis also indicated competition for the vitamin thiamine and downregulation of dissimilatory sulfate reduction and key redox proteins in R. bromii in the co-cultures, thus demonstrating the wide-ranging consequences of inter-species interactions in this model system.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Bactérias
/
Colo
/
Interações Microbianas
/
Transcriptoma
/
Formiatos
Tipo de estudo:
Prognostic_studies
Limite:
Humans
Idioma:
En
Revista:
Environ Microbiol
Assunto da revista:
MICROBIOLOGIA
/
SAUDE AMBIENTAL
Ano de publicação:
2019
Tipo de documento:
Article
País de afiliação:
Reino Unido