Coinducible Catabolism of 1-Naphthol via Synergistic Regulation of the Initial Hydroxylase Genes in Sphingobium sp. Strain B2

Copyright © 2021 American Society for Microbiology..

1-Naphthol, a widely used raw material for organic synthesis, is also a well-known organic pollutant. Due to its high toxicity, 1-naphthol is rarely used by microorganisms as the sole carbon source for growth. In this study, catabolism of 1-naphthol by Sphingobium sp. strain B2 was found to be greatly enhanced by additional supplementation with primary carbon sources (e.g., glucose, maltose, and sucrose), and 1-naphthol was even used as the carbon source for growth when strain B2 cells had been preinduced by both 1-naphthol and glucose. A distinct two-component flavin-dependent monooxygenase, NdcA1A2, was found to be responsible for the initial hydroxylation of 1-naphthol to 1,2-dihydroxynaphthalene, a more toxic compound. Transcriptional levels of ndcA1A2 genes were significantly upregulated when strain B2 cells were cultured with both 1-naphthol and glucose compared to cells cultured with only 1-naphthol or glucose. Two transcriptional regulators, the activator NdcS and the inhibitor NdcR, were found to play key roles in the synergistic regulation of the transcription of the 1-naphthol initial catabolism genes ndcA1A2IMPORTANCE Cometabolism is a widely observed phenomenon, especially in the field of microbial catabolism of highly toxic xenobiotics. However, the mechanisms of cometabolism are ambiguous, and the roles of the obligately coexisting growth substrates remain largely unknown. In this study, we revealed that the roles of the coexisting primary carbon sources (e.g., glucose) in the enhanced catabolism of the toxic compound 1-naphthol in Sphingobium sp. strain B2 were not solely because they were used as growth substrates to support cell growth but, more importantly, because they acted as coinducers to interact with two transcriptional regulators, the activator NdcS and the inhibitor NdcR, to synergistically regulate the transcription of the 1-naphthol initial catabolism genes ndcA1A2 Our findings provide new insights into the cometabolic mechanism of highly toxic compounds in microorganisms.

Medienart:

E-Artikel

Erscheinungsjahr:

2021

Erschienen:

2021

Enthalten in:

Zur Gesamtaufnahme - volume:87

Enthalten in:

Applied and environmental microbiology - 87(2021), 11 vom: 11. Mai

Sprache:

Englisch

Beteiligte Personen:

Huang, Junwei [VerfasserIn]
Chen, Dian [VerfasserIn]
Kong, Xiangkun [VerfasserIn]
Wu, Shurui [VerfasserIn]
Chen, Kai [VerfasserIn]
Jiang, Jiandong [VerfasserIn]

Links:

Volltext

Themen:

1-naphthol
2A71EAQ389
Bacterial Proteins
Coinducible catabolism
Cometabolism
EC 1.-
Journal Article
Mixed Function Oxygenases
Naphthols
NdcA1A2
Research Support, Non-U.S. Gov't
Synergistic regulation

Anmerkungen:

Date Completed 01.06.2021

Date Revised 12.11.2021

published: Electronic-Print

Citation Status MEDLINE

doi:

10.1128/AEM.00170-21

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM323276857