Growing cultures of Bacillus subtilis bifurcate into subpopulations of motile individuals and non-motile chains of cells that are differentiated at the level of gene expression. The motile cells are ON and the chaining cells are OFF for transcription that depends on RNA polymerase and the alternative sigma factor sigma(D). Here we show that chaining cells were OFF for sigma(D)-dependent gene expression because sigma(D) levels fell below a threshold and sigma(D) activity was inhibited by the anti-sigma factor FlgM. The probability that sigma(D) exceeded the threshold was governed by the position of the sigD gene. The proportion of ON cells increased when sigD was artificially moved forward in the 27 kb fla/che operon. In addition, we identified a new sigma(D)-dependent promoter that increases sigD expression and may provide positive feedback to stabilize the ON state. Finally, we demonstrate that ON/OFF motility states in B. subtilis are a form of development because mosaics of stable and differentiated epigenotypes were evident when the normally dispersed bacteria were forced to grow in one dimension.
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http://dx.doi.org/10.1111/j.1365-2958.2010.07112.x | DOI Listing |
Nucleic Acids Res
January 2025
EGM CNRS, Université Paris-Cité,Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005 Paris, France.
Faced with nutritional stress, some bacteria form endospores capable of enduring extreme conditions for long periods of time; yet the function of many proteins expressed during sporulation remains a mystery. We identify one such protein, KapD, as a 3'-exoribonuclease expressed under control of the mother cell-specific transcription factors SigE and SigK in Bacillus subtilis. KapD dynamically assembles over the spore surface through a direct interaction with the major crust protein CotY.
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January 2025
School of Chemical Engineering, Yeungnam University, Gyeongsan, Republic of Korea.
Crystal Violet (CV) is a vibrant and harmful dye known for its toxicity to aquatic life and potential carcinogenic effects on humans. This study explores the removal of CV through photocatalysis driven by visible light, as well as examining the antibacterial and antibiofilm characteristics of zinc oxide nanoparticles (ZnO NPs) synthesized from the aerial roots of Ficus benghalensis. Various characterization techniques were employed to confirm the optical properties, crystal lattices, and morphology of ZnO NPs.
View Article and Find Full Text PDFSci Rep
January 2025
Laboratory of Extremophiles Biology, Department of Microbiology, Faculty of Biology, University of Gdansk, Wita Stwosza 59, Gdansk, 80-308, Poland.
In this study, we evaluated the combined effect between MLE-15, a modular lytic enzyme composed of four building blocks, and reline, a natural deep eutectic solvent. The bioinformatic analysis allowed us to determine the spatial architecture of MLE-15, whose components were bactericidal peptide cecropin A connected via a flexible linker to the cell wall binding domain (CBD) of mesophilic 201ϕ2 - 1 endolysin and catalytic domain (EAD) of highly thermostable Ph2119 endolysin. The modular enzyme showed high thermostability with the melting temperature of 93.
View Article and Find Full Text PDFNPJ Biofilms Microbiomes
January 2025
FLOW, Department of Engineering Mechanics, KTH, Stockholm, Sweden.
Biofilms constitute one of the most common forms of living matter, playing an increasingly important role in technology, health, and ecology. While it is well established that biofilm growth and morphology are highly dependent on the external flow environment, the precise role of fluid friction has remained elusive. We grew Bacillus subtilis biofilms on flat surfaces of a channel in a laminar flow at wall shear stresses spanning one order of magnitude (τ = 0.
View Article and Find Full Text PDFJ Gen Appl Microbiol
January 2025
Department of Science, Technology and Innovation, Kobe University.
As the first step toward understanding how NADPH levels are regulated in Bacillus subtilis, we sought to obtain mutant strains with enhanced NADPH levels. Our previous study demonstrated that in a strain of B. subtilis expressing bacterial luciferase derived from Photorhabdus luminescens, artificially enhancing NADPH levels enhanced luciferase luminescence in the colonies.
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