Background: Secondary metabolism in Serratia sp. ATCC 39006 (Serratia 39006) is controlled via a complex network of regulators, including a LuxIR-type (SmaIR) quorum sensing (QS) system. Here we investigate the molecular mechanism by which phosphate limitation controls biosynthesis of two antibiotic secondary metabolites, prodigiosin and carbapenem, in Serratia 39006.
Results: We demonstrate that a mutation in the high affinity phosphate transporter pstSCAB-phoU, believed to mimic low phosphate conditions, causes upregulation of secondary metabolism and QS in Serratia 39006, via the PhoBR two-component system. Phosphate limitation also activated secondary metabolism and QS in Serratia 39006. In addition, a pstS mutation resulted in upregulation of rap. Rap, a putative SlyA/MarR-family transcriptional regulator, shares similarity with the global regulator RovA (regulator of virulence) from Yersina spp. and is an activator of secondary metabolism in Serratia 39006. We demonstrate that expression of rap, pigA-O (encoding the prodigiosin biosynthetic operon) and smaI are controlled via PhoBR in Serratia 39006.
Conclusion: Phosphate limitation regulates secondary metabolism in Serratia 39006 via multiple inter-linked pathways, incorporating transcriptional control mediated by three important global regulators, PhoB, SmaR and Rap.
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http://dx.doi.org/10.1186/1471-2180-9-112 | DOI Listing |
Front Immunol
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Department of General Surgery, First Affiliated Hospital of Anhui Medical University, Hefei, China.
Background: Adenocarcinoma of the esophagogastric junction (AEGJ) is a highly aggressive tumor that frequently metastasizes to the liver. Understanding the cellular and molecular mechanisms that drive this process is essential for developing effective therapies.
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Front Bioeng Biotechnol
January 2025
Department of Agrobiotechnology, IFA-Tulln, Institute of Environmental Biotechnology, BOKU University of Natural Resources and Life Sciences Vienna, Tulln an der Donau, Austria.
The number of metal-containing waste streams resulting from electronic end-of life products, metallurgical by-products, and mine tailings to name but a few, is increasing worldwide. In recent decades, the potential to exploit these waste streams as valuable secondary resources to meet the high demand of critical and economically important raw materials has become more prominent. In this review, fundamental principles of bio-based metal recovery technologies are discussed focusing on microbial metabolism-dependent and metabolism-independent mechanisms as sustainable alternatives to conventional chemical metal recovery methods.
View Article and Find Full Text PDFFront Plant Sci
January 2025
College of Life Sciences, Northwest Agricultural and Forestry University, Yangling, Shaanxi, China.
As an efficient gene editing tool, the CRISPR/Cas9 system has been widely employed to investigate and regulate the biosynthetic pathways of active ingredients in medicinal plants. CRISPR technology holds significant potential for enhancing both the yield and quality of active ingredients in medicinal plants. By precisely regulating the expression of key enzymes and transcription factors, CRISPR technology not only deepens our understanding of secondary metabolic pathways in medicinal plants but also opens new avenues for drug development and the modernization of traditional Chinese medicine.
View Article and Find Full Text PDFKorean J Gastroenterol
January 2025
Section of Haematology, Department of Pathology and Laboratory Medicine, Aga Khan University, Karachi, Pakistan.
Microangiopathic hemolytic anemia (MAHA) is a rare subtype of hemolytic anemia characterized by elevated hemolytic markers and red blood cell destruction. Though uncommon, MAHA can occur as a complication of acute pancreatitis because of the associated inflammatory response. Patients with MAHA secondary to pancreatitis show favorable outcomes when treated with plasma exchange.
View Article and Find Full Text PDFFood Res Int
February 2025
Department of Food Science, University of Copenhagen, Rolighedsvej 26, 1958 Frederiksberg C, Denmark. Electronic address:
Currently, little is known about how complex carbohydrates (maltodextrins) with varying degrees of polymerisation (DP) and molecular branching interact with α-amylase in human saliva and the associated amounts and structures of generated reducing sugars. Therefore, this study aimed to investigate salivary α-amylase and the subsequent reducing sugars generated with complex carbohydrate stimuli. A secondary aim was to investigate reducing sugar generation and complex carbohydrate taste sensitivity.
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