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Zhang C, Zhao Y, Li Z, Wang W, Huang Y, Pan G, Fan K. Molecular mechanism of GylR-mediated regulation of glycerol metabolism in Streptomyces clavuligerus NRRL 3585. Front Microbiol 2022; 13:1078293. [PMID: 36504789 PMCID: PMC9732521 DOI: 10.3389/fmicb.2022.1078293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Accepted: 11/07/2022] [Indexed: 11/27/2022] Open
Abstract
Glycerol is a readily available and low-cost simple polyol compound, which can be used as a carbon source for microorganisms to produce various value-added products. Understanding the underlying regulatory mechanism in glycerol metabolism is critical for making better use of glycerol for diverse applications. In a few reported Streptomyces strains, the glycerol utilization gene cluster (glp operon) was shown to be regulated by the IclR family transcriptional regulator GylR. However, the molecular regulatory mechanism mediated by GylR has not been fully elucidated. In this study, we first analyzed the available Actinobacteria genomes in the NCBI Genome database, and found that the glp operon-like gene clusters are conserved in Streptomyces and several other genera of Actinobacteria. By taking Streptomyces clavuligerus NRRL 3585 as a model system, we identified that GylR represses the expressions of glp operon and gylR by directly binding to their promoter regions. Both glycerol-3-phosphate and dihydroxyacetone phosphate can induce the dissociation of GylR from its binding sequences. Furthermore, we identified a minimal essential operator site (a palindromic 18-bp sequence) of GylR-like regulators in Streptomyces. Our study for the first time reported the binding sequences and effector molecules of GylR-like proteins in Streptomyces. The molecular regulatory mechanism mediated by GylR presumably exists widely in Streptomyces. Our findings would facilitate the design of glycerol utilization pathways for producing valuable products. Moreover, our study provided new basic elements for the development of glycerol-inducible regulatory tools for synthetic biology research in the future.
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Affiliation(s)
- Chaobo Zhang
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China,University of Chinese Academy of Sciences, Beijing, China
| | - Youbao Zhao
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Zilong Li
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Weishan Wang
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China,University of Chinese Academy of Sciences, Beijing, China
| | - Ying Huang
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China,University of Chinese Academy of Sciences, Beijing, China
| | - Guohui Pan
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China,University of Chinese Academy of Sciences, Beijing, China
| | - Keqiang Fan
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China,*Correspondence: Keqiang Fan,
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Povedano-Priego C, Jroundi F, Lopez-Fernandez M, Sánchez-Castro I, Martin-Sánchez I, Huertas FJ, Merroun ML. Shifts in bentonite bacterial community and mineralogy in response to uranium and glycerol-2-phosphate exposure. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 692:219-232. [PMID: 31349163 DOI: 10.1016/j.scitotenv.2019.07.228] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Revised: 07/15/2019] [Accepted: 07/15/2019] [Indexed: 06/10/2023]
Abstract
The multi-barrier deep geological repository system is currently considered as one of the safest option for the disposal of high-level radioactive wastes. Indigenous microorganisms of bentonites may affect the structure and stability of these clays through Fe-containing minerals biotransformation and radionuclides mobilization. The present work aimed to investigate the behavior of bentonite and its bacterial community in the case of a uranium leakage from the waste containers. Hence, bentonite microcosms were amended with uranyl nitrate (U) and glycerol-2-phosphate (G2P) and incubated aerobically for 6 months. Next generation 16S rRNA gene sequencing revealed that the bacterial populations of all treated microcosms were dominated by Actinobacteria and Proteobacteria, accounting for >50% of the community. Additionally, G2P and nitrate had a remarkable effect on the bacterial diversity of bentonites by the enrichment of bacteria involved in the nitrogen and carbon biogeochemical cycles (e.g. Azotobacter). A significant presence of sulfate-reducing bacteria such as Desulfonauticus and Desulfomicrobium were detected in the U-treated microcosms. The actinobacteria Amycolatopsis was enriched in G2P‑uranium amended bentonites. High-Angle Annular Dark-Field Scanning Transmission Electron Microscopy analyses showed the capacity of Amycolatopsis and a bentonite consortium formed by Bradyrhizobium-Rhizobium and Pseudomonas to precipitate U as U phosphate mineral phases, probably due to the phosphatase activity. The different amendments did not affect the mineralogy of the bentonite pointing to a high structural stability. These results would help to predict the impact of microbial processes on the biogeochemical cycles of elements (N and U) within the bentonite barrier under repository relevant conditions and to determine the changes in the microbial community induced by a uranium release.
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Affiliation(s)
- Cristina Povedano-Priego
- Department of Microbiology, University of Granada, Campus Fuentenueva s/n, 18071 Granada, Spain.
| | - Fadwa Jroundi
- Department of Microbiology, University of Granada, Campus Fuentenueva s/n, 18071 Granada, Spain.
| | - Margarita Lopez-Fernandez
- Institute of Resource Ecology, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01328 Dresden, Germany.
| | - Iván Sánchez-Castro
- Department of Microbiology, University of Granada, Campus Fuentenueva s/n, 18071 Granada, Spain.
| | - Inés Martin-Sánchez
- Department of Microbiology, University of Granada, Campus Fuentenueva s/n, 18071 Granada, Spain.
| | - F Javier Huertas
- Instituto Andaluz de Ciencias de la Tierra, CSIC - University of Granada, 18100 Granada, Spain.
| | - Mohamed L Merroun
- Department of Microbiology, University of Granada, Campus Fuentenueva s/n, 18071 Granada, Spain.
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Multi-level regulation of coelimycin synthesis in Streptomyces coelicolor A3(2). Appl Microbiol Biotechnol 2019; 103:6423-6434. [PMID: 31250060 PMCID: PMC6667686 DOI: 10.1007/s00253-019-09975-w] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Revised: 06/06/2019] [Accepted: 06/12/2019] [Indexed: 11/03/2022]
Abstract
Despite being a yellow pigment visible to the human eye, coelimycin (CPK) remained to be an undiscovered secondary metabolite for over 50 years of Streptomyces research. Although the function of this polyketide is still unclear, we now know that its "cryptic" nature is attributed to a very complex and precise mechanism of cpk gene cluster regulation in the model actinomycete S. coelicolor A3(2). It responds to the stringent culture density and timing of the transition phase by the quorum-sensing butanolide system and to the specific nutrient availability/uptake signals mediated by the global (pleiotropic) regulators; many of which are two-component signal transduction systems. The final effectors of this regulation cascade are predicted to be two cluster-situated Streptomyces antibiotic regulatory proteins (SARPs) putatively activating the expression of type I polyketide synthase (PKS I) genes. After its synthesis, unstable, colorless antibiotic coelimycin A reacts with specific compounds in the medium losing its antibacterial properties and giving rise to yellow coelimycins P1 and P2. Here we review the current knowledge on coelimycin synthesis regulation in Streptomyces coelicolor A3(2). We focus on the regulatory feedback loop which interconnects the butanolide system with other cpk cluster-situated regulators. We also present the effects exerted on cpk genes expression by the global, pleiotropic regulators, and the regulatory connections between cpk and other biosynthetic gene clusters.
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