Molecular Biology and Physiology
Resource Report | Molecular Biology and PhysiologyAbsolute Measurements of mRNA Translation in Caulobacter crescentus Reveal Important Fitness Costs of Vitamin B12 ScavengingCaulobacter crescentus is a model system of the bacterial cell cycle culminating in asymmetric cell division, with each daughter cell inheriting a distinct set of proteins. While a genetic network of master transcription factors coordinates the cell cycle timing of transcription for nearly 20% of Caulobacter genes, we lack knowledge of how many of each...
Research Article | Molecular Biology and PhysiologyType E Botulinum Neurotoxin-Producing Clostridium butyricum Strains Are Aerotolerant during Vegetative GrowthBotulinum neurotoxins, the causative agents of the potentially fatal disease of botulism, are produced by certain Clostridium strains during vegetative growth, usually in anaerobic environments. Our findings indicate that, contrary to current understanding, the growth of neurotoxigenic C. butyricum strains and botulinum neurotoxin type E production can continue upon transfer from anaerobic to aerated conditions and...
Research Article | Molecular Biology and PhysiologyComparative Transcriptome Analysis Shows Conserved Metabolic Regulation during Production of Secondary Metabolites in Filamentous FungiSecondary metabolites are a major source of pharmaceuticals, especially antibiotics. However, the development of efficient processes of production of secondary metabolites has proved troublesome due to a limited understanding of the metabolic regulations governing secondary metabolism. By analyzing the conservation in gene expression across secondary metabolite-producing fungal species, we identified a metabolic signature that links...
Research Article | Molecular Biology and PhysiologyGenomic Characterization and Virulence Potential of Two Fusarium oxysporum Isolates Cultured from the International Space StationThis is the first study to isolate and characterize F. oxysporum isolates from a built environment, as well as one that has been exposed to space. The characterization and analysis of these two genomes may have important implications for the medical, agricultural, and food industries as well as for the health of the crew who coinhabit the ISS with these strains.
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Research Article | Molecular Biology and PhysiologyClostridium difficile Modulates the Gut Microbiota by Inducing the Production of Indole, an Interkingdom Signaling and Antimicrobial MoleculeClostridium difficile infection is the leading cause of hospital-acquired and antibiotic-associated diarrhea worldwide. C. difficile flourishes in the colon after the diversity of the beneficial and protective gut microbiota have...
Research Article | Molecular Biology and PhysiologyCarbon Fate and Flux in Prochlorococcus under Nitrogen LimitationPhotosynthetic microbes are the predominant sources of organic carbon in the sunlit regions of the ocean. During photosynthesis, nitrogen and carbon metabolism are coordinated to synthesize nitrogen-containing organics such as amino acids and nucleic acids. In large regions of the ocean, nitrogen is thought to limit the growth of phytoplankton. The impact of nitrogen limitation on the synthesis of organic carbon is not well understood,...
Research Article | Molecular Biology and PhysiologyMinor Isozymes Tailor Yeast Metabolism to Carbon AvailabilityGene duplication is one of the main evolutionary paths to new protein function. Typically, duplicated genes either accumulate mutations and degrade into pseudogenes or are retained and diverge in function. Some duplicated genes, however, show long-term persistence without apparently acquiring new function. An important class of isozymes consists of those that catalyze the same reaction in the same compartment, where knockout of one...
Research Article | Molecular Biology and PhysiologySystems-Level Analysis of Oxygen Exposure in Zymomonas mobilis: Implications for Isoprenoid ProductionMicrobially generated biofuels and bioproducts have the potential to provide a more environmentally sustainable alternative to fossil-fuel-derived products. In particular, isoprenoids, a diverse class of natural products, are chemically suitable for use as high-grade transport fuels and other commodity molecules. However, metabolic engineering for increased production of isoprenoids and other bioproducts is limited by an incomplete...
Research Article | Molecular Biology and PhysiologyOxidative Pathways of Deoxyribose and Deoxyribonate CatabolismDeoxyribose is one of the building blocks of DNA and is released when cells die and their DNA degrades. We identified a bacterium that can grow with deoxyribose as its sole source of carbon even though its genome does not contain any of the known genes for breaking down deoxyribose. By growing many mutants of this bacterium together on deoxyribose and using DNA sequencing to measure the change in the mutants’ abundance, we identified...
Research Article | Molecular Biology and PhysiologyEmergent Subpopulation Behavior Uncovered with a Community Dynamic Metabolic Model of Escherichia coli Diauxic GrowthEscherichia coli diauxie is a fundamental example of metabolic adaptation, a phenomenon that is not yet completely understood. Further insight into this process can be achieved by integrating experimental and computational modeling methods. We present a dynamic metabolic modeling approach that captures diauxie as an emergent property of subpopulation dynamics in...