What is the nature of cell walls in diatoms

Diatoms are unicellular photosynthetic algae that produce a silica exoskeleton (frustule) which exposes a highly ordered nano to micro scale morphology. In recent years there has been a growing interest in modifying diatom frustules for technological applications. This is achieved by adding non-essential metals to the growth medium of diatoms which in turn modifies morphology, composition, and resulting properties of the frustule. Here, we investigate the frustule formation in diatom Craspedostauros sp., including changes to overall morphology, silica thickness, and composition, in the presence of Al 3+ ions at different concentrations. Our results show that in the presence of Al 3+ the total silica uptake from the growth medium increases, although a decrease in the growth rate is observed. This leads to a higher inorganic content per diatom resulting in a decreased pore diameter and a thicker frustule as evidenced by electron microscopy. Furthermore, 27Al solid-state NMR, FIB-SEM, and EDS results confirm that Al 3+ becomes incorporated into the frustule during the silicification process, thus, improving hydrolysis resistance. This approach may be extended to a broad range of elements and diatom species towards the scalable production of silica materials with tunable hierarchical morphology and chemical composition. Unicellular photosynthetic algae commonly known as diatoms are ubiquitous throughout most aquatic environments Besides salinity, light intensity/wavelength, pH...

Step 1/2 Diatoms are a group of single-celled algae that are known for their unique and intricate cell walls. These cell walls are made up of silica, which is a major component of glass. This silica-based cell wall is also known as a frustule. The frustule is composed of two overlapping halves, which fit together like a box and its lid. The intricate patterns and structures on the frustule provide strength and protection to the diatom, as well as aid in the absorption of light for photosynthesis. So, the nature of cell walls in diatoms is that they are made up of silica and form a unique, intricate structure called a frustule.

Diatoms are unicellular or colonial photoautotrophic microalgae, eukaryotic organisms classified as protists of the group of the Bacillariophyta. They are characterized by the unique feature of possessing a cell wall made of silica. Diatoms form an extremely diverse and evolutionarily successful group. They are found in all marine and freshwater habitats and in moist terrestrial habitats, being the most diverse group of algae, the number of species being estimated to reach between 100,000 (Mann and Vanormelingen • Apoya-Horton MD, Yin L, Underwood GJC, Gretz MR (2006) Movement modalities and responses to environmental changes of the mudflat diatom Cylindrotheca closterium (Bacillariophyceae). J Phycol 42:379–390. • Armbrust EV (2009) The life of diatoms in the world’s oceans. Nature 459:185–192. • Arrigo KR (2014) Sea ice ecosystems. Annu Rev Mar Sci 6:439–467. • Benoiston A, Ibarbalz FM, Bittner L et al (2017) The evolution of diatoms and their biogeochemical functions. Philos Trans R Soc B Biol Sci 372:20160397. • Bohórquez J, McGenity TJ, Papaspyrou S et al (2017) Different types of diatom-derived extracellular polymeric substances drive changes in heterotrophic bacterial communities from intertidal sediments. Front Microbiol 8:245. • Bondoc KGV, Heuschele J, Gillard J et al (2016a) Selective silicate-directed motility in diatoms. Nat Commun 7:10540. • Bondoc KGV, Lembke C, Vyverman W, Pohnert G (2016b) Searching for a mate: pheromone-directed movement of the benthic di...