Background
Limited research has been conducted on energy fluctuation during the transition state, despite the critical role of energy supply in microbial physiological metabolism.
Results
This study aimed to investigate the regulatory function of transition state transcription factor AbrB on energy metabolism in
Bacillus licheniformis
WX-02. Firstly, the deletion of
abrB
was found to prolong the cell generation time, significantly reducing the intercellular ATP concentration and NADH/NAD
+
ratio at the early stage. Subsequently, various target genes and transcription factors regulated by AbrB were identified through in vitro verification assays. Specifically, AbrB was shown to modulate energy metabolism by directly regulating the expression of genes
pyk
and
pgk
in substrate-level phosphorylation, as well as genes
narK
and
narGHIJ
associated with nitrate respiration. In terms of oxidative phosphorylation, AbrB not only directly regulated ATP generation genes, including
cyd
,
atpB
,
hmp
,
ndh
,
qoxA
and
sdhC
, but also influenced the expression of NAD-dependent enzymes and intracellular NADH/NAD
+
ratio. Additionally, AbrB positively affected the expression of transcription factors CcpN, Fnr, Rex, and ResD involved in energy supply, while negatively affected the regulator CcpA. Overall, this study found that AbrB positively regulates both substrate-level phosphorylation and oxidative phosphorylation, while negatively regulating nitrate respiration.
Conclusions
This study proposes a comprehensive regulatory network of AbrB on energy metabolism in
Bacillus
, expanding the understanding of regulatory mechanisms of AbrB and elucidating energy fluctuations during the transition state.
Supplementary Information
The online version contains supplementary material available at 10.1186/s12934-024-02572-1.
