How Light Control Works in a Unique Micro-Algae Species

Greg Howard
19th March, 2024

How Light Control Works in a Unique Micro-Algae Species

Image Source: Natural Science News, 2024

Key Findings

  • In Italy, scientists found that P. strigosum diatoms' silica shells enhance photosynthesis and block UV rays
  • The shells manipulate light through diffraction, refraction, and wave-guiding to protect and nourish the diatoms
  • These findings could inspire new technology based on diatoms' natural light-managing structures
Diatoms, a type of microalgae found in all aquatic environments, have intrigued scientists for their remarkable ability to manipulate light. These unicellular organisms are encased in a silica shell, known as a frustule, which has evolved over millions of years to perform complex optical functions. A recent study by the National Research Council (CNR) in Italy[1] has shed light on the sophisticated ways in which the frustule of Pleurosigma strigosum, a species of diatom, modulates light, potentially contributing to the organism's high photosynthetic efficiency. Photosynthesis is the process by which plants, algae, and some bacteria convert light energy into chemical energy. For diatoms, efficient photosynthesis is crucial for their survival and ecological success. However, not all light is beneficial; ultraviolet (UV) radiation can be harmful to these organisms. The CNR study aimed to understand how diatoms manage to favor the transmission of beneficial photosynthetic active radiation (PAR) while minimizing the damage from UV radiation. To do this, researchers employed a variety of techniques to examine the frustules of P. strigosum. They used transmission imaging to observe how light passes through the frustule, digital holography to capture three-dimensional images, photoluminescence spectroscopy to study how the frustule emits light, and numerical simulations to predict how light behaves as it travels through the frustule's structures. This combination of approaches allowed for a comprehensive analysis of the frustule's interaction with light. The study found that the frustule of P. strigosum is capable of selectively transmitting PAR while blocking out harmful UV rays. This selective transmission is due to the frustule's ability to manipulate light through diffraction, refraction, and wave-guiding. Diffraction occurs when light encounters an obstacle or opening, causing it to spread out. Refraction is the bending of light as it passes from one medium to another, and wave-guiding is the process of directing light waves along a path. These findings are in line with previous research[2] that examined the light modulation capabilities of diatom frustules, using Gomphonema parvulum as a model. That study also used numerical analysis to understand the complex interference patterns created by the frustule's nanostructures. The CNR study expands on this knowledge by demonstrating the practical effects of these patterns in living P. strigosum cells. Understanding the genetic factors behind the formation of these intricate frustules is another area of interest. Earlier work[3] identified specific proteins involved in the biomineralization process of diatoms. These proteins, with ankyrin repeats, suggest a coordinated assembly process, which could explain the precision of the frustule's nanostructures. The CNR study does not delve into the genetic aspects, but it builds on the idea that the frustule's design is not random but a result of highly controlled biological processes. Additionally, the resilience of diatoms to UV radiation has been a subject of fascination. A study[4] on the diatom species Ctenophora pulchella showed that despite the absence of UV-absorbing pigments, these organisms could withstand UV exposure. This resilience was thought to be linked to the protective role of the frustule, which the CNR study supports by demonstrating the selective light transmission properties of the frustule. Moreover, the diversity of diatom morphologies, as seen in Phaeodactylum tricornutum[5], indicates that different shapes and structures may have unique functional advantages. While the CNR study focuses on P. strigosum, it suggests that the frustule's optical properties could be a common feature among diatoms, contributing to their adaptability and success. In conclusion, the CNR study provides compelling evidence that the frustule of P. strigosum diatoms is an evolutionary masterpiece of nanoengineering, capable of protecting the cell from UV damage while enhancing photosynthetic efficiency. This research not only deepens our understanding of diatom biology but also opens up possibilities for developing new materials inspired by these natural photonic structures. The study is a significant step forward in the field of biophotonics, highlighting the potential of nature's designs in advancing technology.

BiochemPlant ScienceMarine Biology

References

Main Study

1) Multiple-pathways light modulation in Pleurosigma strigosum bi-raphid diatom.

Published 18th March, 2024

https://doi.org/10.1038/s41598-024-56206-y

Related Studies

2) Numerical Analysis of the Light Modulation by the Frustule of Gomphonema parvulum: The Role of Integrated Optical Components.

https://doi.org/10.3390/nano13010113

3) The molecular basis for pore pattern morphogenesis in diatom silica.

https://doi.org/10.1073/pnas.2211549119

4) Underwater Light Manipulation by the Benthic Diatom Ctenophora pulchella: From PAR Efficient Collection to UVR Screening.

https://doi.org/10.3390/nano11112855

5) Comparative Structural and Functional Analyses of the Fusiform, Oval, and Triradiate Morphotypes of Phaeodactylum tricornutum Pt3 Strain.

https://doi.org/10.3389/fpls.2021.638181


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