Structural Stabilization of Alginate for Imaging Hydrogel-encapsulated Bacterial Cells Using LV-STEM

abstract

English

Hydrogels are polymer-based materials capable of binding large amounts of water, making them valuable in various applications, including medicine or agriculture. While some hydrogels are synthetically produced, others occur naturally. A notable example is the biopolymer alginate, synthesized by the bacterium Azotobacter vinelandii, a plant growth-promoting microorganism (PGPR). Alginate production allows A. vinelandii to form a protective polysaccharide capsule around its cells, protecting them from drying out and other environmental stress conditions. To better understand the properties and behaviour of alginate hydrogels it is valuable to have detailed information on the structure of the polymer net. The imaging of hydrogel samples, let alone complex samples such as hydrogel-encapsulated cells, is highly challenging for electron microscopy. There are several studies relying on the various combinations of sample preparation approaches (such as lyophilisation) and different scanning electron microscopy techniques (e.g., ESEM, cryo-SEM). However, to observe also the intracellular ultrastructure of the studied cells, it is necessary to employ transmission electron microscopy techniques. In our study, we focused on the development of a sample preparation protocol suitable for alginate-encapsulated A. vinelandii cells imaged using low-voltage scanning transmission electron microscopy (LV-STEM).

Alginate; Azotobacter vinelandii; Electron microscopy; Encapsulation

MRÁZOVÁ, K.; HAVLÍČKOVÁ, A.; ČERNAYOVÁ, D.; SEDLÁČEK, P.; KRZYŽÁNEK, V.

7. 9. 2025

Slovene Society for Microscopy

Ljubljana

978-961-94264-4-9

17th Multinational Congress on Microscopy: book of abstract

1st

277

278

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