In a concept study the ability to induce heterogeneous ice formation by Bacterial Ghosts (BGs) from Escherichia coli carrying ice nucleation protein InaZ from Pseudomonas syringae in their outer membrane was investigated by a droplet-freezing assay of ultra-pure water. As determined by the median freezing temperature and cumulative ice nucleation spectra it could be demonstrated that both the living recombinant E. coli and their corresponding BGs functionally display InaZ on their surface. Under the production conditions chosen both samples belong to type II ice-nucleation particles inducing ice formation at a temperature range of between -5.6 °C and -6.7 °C, respectively. One advantage for the application of such BGs over their living recombinant mother bacteria is that they are non-living native cell envelopes retaining the biophysical properties of ice nucleation and do no longer represent genetically modified organisms (GMOs).
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http://dx.doi.org/10.1080/21655979.2017.1284712 | DOI Listing |
J Phys Chem A
January 2025
Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States.
Aerosols containing biological material (i.e., bioaerosols) impact public health by transporting toxins, allergens, and diseases and impact the climate by nucleating ice crystals and cloud droplets.
View Article and Find Full Text PDFNano Lett
January 2025
"The Belt and Road Initiative" Advanced Materials International Joint Research Center of Hebei Province, School of Materials Science and Engineering, Hebei University of Technology, Tianjin 300401, China.
The microscopic mechanisms by which solutes modulate water freezing are fundamental for controlling the freezing of various environmental and cryobiotic systems. Although our understanding of the initiation mechanisms of pure water freezing is becoming clearer, the microscopic pictures regarding ice nucleation in complex systems such as solutions still rely on theory assumption and empirical formulation. Here, we experimentally demonstrate that solutes modulate water freezing through affecting critical ice nucleus formation.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Department of Materials Science and Engineering, City University of Hong Kong, Hong Kong, Kowloon 999077, China.
Heterogeneous ice nucleation is a widespread phenomenon in nature. Despite extensive research on ice nucleation near biological antifreeze proteins, a probe for ice nucleation and growth processes at the atomic level is still lacking. Herein, we present simulation evidence of the heterogeneous ice nucleation process on the ice-binding surface (IBS) of the antifreeze protein (TmAFP).
View Article and Find Full Text PDFVet Res Commun
January 2025
Faculty of Agriculture, University Farm, Utsunomiya University, Tochigi, 321-4415, Japan.
The purpose of this study was to improve the quality of frozen-thawed canine spermatozoa through the optimization of glycerol concentration (GC) and freezing rate in the semen freezing protocol. Ejaculates from nine dogs were diluted with an extender containing 0%, 1.5%, 3%, 6%, or 9% glycerol.
View Article and Find Full Text PDFJ Food Sci
January 2025
Department of Human Nutrition, Food, and Animal Sciences, University of Hawai'i at Mānoa, Honolulu, Hawai'i, USA.
Freezing extends the shelf life of foods but often leads to structural damage due to ice crystal formation, negatively impacting quality attributes. Oscillating magnetic field (OMF)-assisted supercooling has emerged as a potential technique to overcome these limitations by inhibiting ice nucleation and maintaining foods in a supercooled state. Despite its potential, the effectiveness and underlying mechanisms of OMF-assisted supercooling remain subjects of debate.
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