High-resolution transmission electron microscopy and electron holography were used to study the habits of exceptionally large magnetite crystals in coccoid magnetotactic bacteria. In addition to the crystal habits, the crystallographic positioning of successive crystals in the magnetosome chain appears to be under strict biological control.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1183320 | PMC |
http://dx.doi.org/10.1128/AEM.71.8.4902-4905.2005 | DOI Listing |
Geobiology
October 2024
Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts, USA.
Silicified peritidal carbonates of the Tonian Draken Formation, Spitsbergen, contain highly diverse and well-preserved microfossil assemblages dominated by filamentous microbial mats, but also including diverse benthic and/or allochthonous (possibly planktonic) microorganisms. Here, we characterize eight morphospecies in focused ion beam (FIB) ultrathin sections using transmission electron microscopy (TEM) and X-ray absorption near-edge structure (XANES) spectromicroscopy. Raman and XANES spectroscopies show the highly aromatic molecular structure of preserved organic matter.
View Article and Find Full Text PDFMar Pollut Bull
September 2023
DHI, Agern Allé 5, DK-2970 Hørsholm, Denmark.
The approved method for testing the efficacy of ballast water management systems with respect to killing 10-50 μm organisms uses movements of the organisms or the vital stains CMFDA/FDA. The present study demonstrates that certain freshwater coccoid chlorophytes, known or suspected to contain a highly resistant cell wall component (algaenan), stain poorly with CMFDA/FDA, resulting in false negatives. The staining rates for the most dominant species were determined and were approx.
View Article and Find Full Text PDFGeobiology
September 2023
UWA-School of Agriculture and Environment, The University of Western Australia, 35 Stirling Highway, Crawley, Western Australia, 6009, Australia.
Dolomite (CaMg(CO ) ) precipitation is kinetically inhibited at surface temperatures and pressures. Experimental studies have demonstrated that microbial extracellular polymeric substances (EPS) as well as certain clay minerals may catalyse dolomite precipitation. However, the combined association of EPS with clay minerals and dolomite and their occurrence in the natural environment are not well documented.
View Article and Find Full Text PDFFront Microbiol
July 2021
Key Laboratory of Earth and Planetary Physics, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, China.
Magnetotactic bacteria (MTB) are a group of microbes that biomineralize membrane-bound, nanosized magnetite (FeO), and/or greigite (FeS) crystals in intracellular magnetic organelle magnetosomes. MTB belonging to the phylum can form up to several hundreds of FeO magnetosome crystals and dozens of sulfur globules in a single cell. These MTB are widespread in aquatic environments and sometimes account for a significant proportion of microbial biomass near the oxycline, linking these lineages to the key steps of global iron and sulfur cycling.
View Article and Find Full Text PDFAppl Environ Microbiol
April 2021
Institute of Food, Nutrition and Human Health, Massey University, Palmerston North, New Zealand.
is a ubiquitous foodborne pathogen that results in a high rate of mortality in sensitive and immunocompromised people. Contamination of food with is thought to occur during food processing, most often as a result of the pathogen producing a biofilm that persists in the environment and acting as the source for subsequent dispersal of cells onto food. A survey of seafood-processing plants in New Zealand identified the persistent strain 15G01, which has a high capacity to form biofilms.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!