The genes involved in biosynthesis of the major compatible solute ectoine (1,4,5,6-tetrahydro-2-methylpyrimidine carboxylic acid) in halotolerant obligate methanotroph "Methylomicrobium alcaliphilum 20Z" were studied. The complete nucleotide sequences of the structural genes encoding L: -aspartokinase (Ask), L-2,4-diaminobutyric acid transaminase (EctB), L-2,4-diaminobutyric acid acetyltransferase (EctA), and L-ectoine synthase (EctC) were defined and shown to be transcribed as a single operon ectABCask. Phylogenetic analysis revealed high sequence identities (34-63%) of the Ect proteins to those from halophilic heterotrophs with the highest amino acid identities being to Vibrio cholerae enzymes. The chromosomal DNA fragment from "M. alcaliphilum 20Z" containing ectABC genes and putative promoter region was expressed in Escherichia coli. Recombinant cells could grow in the presence of 4% NaCl and synthesize ectoine. The data obtained suggested that despite the ectoine biosynthesis pathway being evolutionary well conserved with respect to the genes and enzymes involved, some differences in their organization and regulation could occur in various halophilic bacteria.
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http://dx.doi.org/10.1007/s00203-005-0042-z | DOI Listing |
Appl Environ Microbiol
December 2024
Biology Department, San Diego State University, San Diego, California, USA.
Unlabelled: Many species of proteobacterial methane-consuming bacteria (methanotrophs) form a hauberk-like envelope represented by a surface (S-) layer protein (SLP) matrix. While several proteins were predicted to be associated with the cell surface, the composition and function of the hauberk matrix remained elusive. Here, we report the identification of the genes encoding the hauberk-forming proteins in two gamma-proteobacterial (Type I) methanotrophs, 5GB1 (EQU24_15540) and 20Z (MEALZ_0971 and MEALZ_0972).
View Article and Find Full Text PDFmSystems
January 2025
Department of Computational Biology, Scientific Center for Genetics and Life Sciences, Sirius University of Science and Technology, Sochi, Russia.
Unlabelled: Context-specific genome-scale model (CS-GSM) reconstruction is becoming an efficient strategy for integrating and cross-comparing experimental multi-scale data to explore the relationship between cellular genotypes, facilitating fundamental or applied research discoveries. However, the application of CS modeling for non-conventional microbes is still challenging. Here, we present a graphical user interface that integrates COBRApy, EscherPy, and RIPTiDe, Python-based tools within the BioUML platform, and streamlines the reconstruction and interrogation of the CS genome-scale metabolic frameworks via Jupyter Notebook.
View Article and Find Full Text PDFMicrob Cell Fact
May 2024
Department of Chemical and Biomolecular Engineering, Sogang University, Seoul, Republic of Korea.
Background: Methane is a greenhouse gas with a significant potential to contribute to global warming. The biological conversion of methane to ectoine using methanotrophs represents an environmentally and economically beneficial technology, combining the reduction of methane that would otherwise be combusted and released into the atmosphere with the production of value-added products.
Results: In this study, high ectoine production was achieved using genetically engineered Methylomicrobium alcaliphilum 20Z, a methanotrophic ectoine-producing bacterium, by knocking out doeA, which encodes a putative ectoine hydrolase, resulting in complete inhibition of ectoine degradation.
Bioresour Technol
May 2024
Cell Factory Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Republic of Korea; Department of Environmental Biotechnology, KRIBB School of Biotechnology, University of Science & Technology (UST), Daejeon 34113, Republic of Korea. Electronic address:
A halotolerant consortium between microalgae and methanotrophic bacteria could effectively remediate in situ CH and CO, particularly using saline wastewater sources. Herein, Methylomicrobium alcaliphilum 20Z was demonstrated to form a mutualistic association with Chlorella sp. HS2 at a salinity level above 3.
View Article and Find Full Text PDFPLoS One
October 2023
Federal Research Center "Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences", G.K. Skryabin Institute of Biochemistry and Physiology of Microorganisms, Russian Academy of Sciences, Pushchino, Moscow Region, Russia.
The methanotrophic bacterium Methylotuvimicrobium alcaliphilum 20Z is an industrially promising candidate for bioconversion of methane into value-added chemicals. Here, we have study the metabolic consequences of the breaking in the tricarboxylic acid (TCA) cycle by fumarase knockout. Two fumarases belonging to non-homologous class I and II fumarases were obtained from the bacterium by heterologous expression in Escherichia coli.
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