The effects of diatom pore-size on the structures and extensibilities of single mucilage molecules

A1 Journal article (refereed)

Internal Authors/Editors

Publication Details

List of Authors: Immanuel Sanka, Eko Agus Suyono, Parvez Alam
Publication year: 2017
Journal: Carbohydrate Research
Volume number: 448
Start page: 35
End page: 42
eISSN: 1873-426X


Diatoms secrete extracellular polymeric substances (EPS), or mucilage,
around the cell wall that may serve to aid in motility and form a
discrete layer that may help maintain thicker layers of EPS that have a
greater role in adhesion. Mucilage molecules adhere to the diatom
frustules, which are biosilica skeletons that develop from the diatom
cell walls. Here, molecular dynamics methods were used to determine the
characteristics of mucilage molecules as a function of pore size;
notably 1,4-α-D-galacturonic acid, 1,4-β-glucuronic acid and 1,4-β-D-mannuronic
acid. These uronic acids differ from each other in structure and
extensibility as a function of their folding characteristics. Here, we
find that when overlain upon a pore, mucilage molecules try to return to
their native folded states but are restrained by their interactions
with the silica surfaces. Furthermore, the extensibility of mucilage
molecules over pore spaces affects the extent of mechanical energy
required to straighten them. As such, different EPS molecules will
affect sliding, friction and adhesion to subsequent layers of EPS in
different ways. We conclude that higher EPS extensibility is homonymous
with higher adhesive or frictive resistance since the molecules will be
able to strain more before they reach the most extended (and thus rigid)
conformation. The research herein is applicable to modern engineering
as it yields insight into the biomimetic design of molecules and
surfaces for improved adhesion or motility.

Last updated on 2019-11-11 at 04:33