Capsules of the diatom Achnanthidium minutissimum arise from fibrillar precursors and foster attachment of bacteria.

ABSTRACT: Achnanthidium minutissimum is a benthic freshwater diatom that forms biofilms on submerged surfaces in aquatic environments. Within these biofilms, A. minutissimum cells produce extracellular structures which facilitate substrate adhesion, such as stalks and capsules. Both consist of extracellular polymeric substance (EPS), but the microstructure and development stages of the capsules are so far unknown, despite a number of hypotheses about their function, including attachment and protection. We coupled scanning electron microscopy (SEM) to bright-field microscopy (BFM) and found that A. minutissimum capsules mostly possess an unstructured surface. However, capsule material that was mechanically stressed by being stretched between or around cells displayed fibrillar substructures. Fibrils

SUBMITTER: Leinweber K 

PROVIDER: S-EPMC4380156 | biostudies-literature | 2015

REPOSITORIES: biostudies-literature