Changes in glycerolipid and fatty acid composition with a change in growth temperature were studied in the cyanobacterium, Synechocystis PCC6803. Under isothermal growth conditions, temperature did not significantly affect the composition of the various classes of lipids, but a decrease in temperature altered the degree of unsaturation of C(18) acids at the sn-1 position, but not that of C(16) acids at the sn-2 position of the glycerol moiety in each class of lipids. When the growth temperature was shifted from 38 degrees C to 22 degrees C, the desaturation of C(18) acids, but not that of C(16) acids, was stimulated. The desaturation of fatty acids occurred only in the light and was inhibited by chloramphenicol, rifampicin and 3-(3,4-dichlorophenyl)-1, 1-dimethylurea, but not by cerulenin, an inhibitor for fatty acid synthesis. These findings suggest that desaturase activities are induced after a shift from a higher to a lower temperature, and that the desaturation of fatty acids is connected with the reactions involved in photosynthetic electron transport.
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http://dx.doi.org/10.1104/pp.92.4.1062 | DOI Listing |
Proc Natl Acad Sci U S A
February 2025
Aix-Marseille Université-CNRS UMR 7283, Institut de Microbiologie de la Méditerranée and Turing Center for Living Systems, Marseille 13009, France.
Despite growing awareness of their importance in soil ecology, the genetic and physiological traits of bacterial predators are still relatively poorly understood. In the course of a predator evolution experiment, we identified a class of genotypes leading to enhanced predation against diverse species. RNA-seq analysis demonstrated that this phenotype is linked to the constitutive activation of a predation-specific program.
View Article and Find Full Text PDFJ Am Soc Mass Spectrom
January 2025
Department of Chemistry, Center for Innovative Technology, Vanderbilt University, Nashville, Tennessee 37235, United States.
Desorption electrospray ionization mass spectrometry imaging (DESI-MSI) provides direct analytical readouts of small molecules that can be used to characterize the metabolic phenotypes of genetically engineered bacteria. In an effort to accelerate the time frame associated with the screening of mutant libraries, we have developed a high-throughput DESI-MSI analytical workflow implementing a single raster line-scan strategy that facilitates the collection of location-resolved molecular information from engineered strains on a subminute time scale. Evaluation of this "Fast-Pass" DESI-MSI phenotyping workflow on analytical standards demonstrated the capability of acquiring full metabolic profiling information with a throughput of ∼40 s per sample.
View Article and Find Full Text PDFPLoS Genet
January 2025
Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle, United Kingdom.
Bacterial cytokinesis begins with polymerization of the tubulin homologue FtsZ into a ring-like structure at midcell, the Z-ring, which recruits the late cell division proteins that synthesize the division septum. Assembly of FtsZ is carefully regulated and supported by a dozen conserved cell division proteins. Generally, these proteins are not essential, but removing more than one is in many cases lethal.
View Article and Find Full Text PDFInt J Syst Evol Microbiol
January 2025
Department of Microorganisms, Leibniz Institute DSMZ German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany.
An obligately anaerobic, spore-forming sulphate-reducing bacterium, strain SB140, was isolated from a long-term continuous enrichment culture that was inoculated with peat soil from an acidic fen. Cells were immotile, slightly curved rods that stained Gram-negative. The optimum temperature for growth was 28 °C.
View Article and Find Full Text PDFInt J Syst Evol Microbiol
January 2025
Department of Biochemistry and Microbiology, Faculty of Pharmaceutical Sciences, Chulalongkorn University, Bangkok 10330, Thailand.
A Gram-stain-positive, facultatively anaerobic, rod-shaped strain, designated SPB1-3, was isolated from tree bark. This strain exhibited heterofermentative production of dl-lactic acid from glucose. Optimal growth was observed at 25-40 °C, pH 4.
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