Effects of light on physico-chemical properties of diatoms

Diatoms are microscopic, unicellular, autotrophic, and ubiquitous. They are the main organisms in the marine ecosystem which have photosynthetic as well as photoprotective and antioxidant properties. All of these properties facilitate the effective production of biomass and oxygen. Chlorophyll a/c and fucoxanthin (Fx) are the core light-harvesting pigments and β-carotene and xanthophylls are photoprotective carotenoids in diatoms. The photophysiology property of diatoms has been widely researched whereas, in their thylakoid membranes the organization of photosynthetic protein complexes is still not completely understood. Along with photosynthetic properties, they also have some phototoxic, photoelimination, and photoregulation properties. Latest studies have demonstrated the importance of the increase in the production of microalgae in a specific condition, especially when illuminated with a specific wavelength of light. Studies have also demonstrated how properties of diatoms, for example, their cellular structure, the composition of lipid on their cell membrane, and metabolism change during prolonged darkness and reillumination with moderate light. Nowadays, artificial light sources like light-emitting diodes are employed in the identification of a particular characteristic and manipulate the behavior of diatom biomass. Production of different types of pigments, which may be used in the diagnosis of some diseases like cancer, is altered either by altering the supplemented nutrients or illumination with a specific wavelength of light, implicating the importance of understanding the influence of light intensity and duration on diatoms.