Artificial light source selection in seaweed production: growth of seaweed and biosynthesis of photosynthetic pigments and soluble protein.

Shitao Huang,Xi Xiao,Zhixing Huang,Yaoru Pan,Ke Li,Jiaping Wu,Yan Yu,Thomas Wernberg,Thibaut De Bettignies,Chaosheng Zhou

doi:10.7717/peerj.11351

Shitao Huang, Xi Xiao + Show 8 more

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https://doi.org/10.7717/peerj.11351

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Abstract

Seaweed growth is often limited by light. Artificial light supply has been well studied in terrestrial agriculture, however, much less is known about its effect in seaweed aquaculture. In this study, the effects of four artificial light sources (white, red, green, and blue LEDs light) on a brown alga Sargassum fusiforme and a green alga Ulva pertusa were investigated. Seaweed growth, accumulation of photosynthetic pigments (chlorophyll a and carotenoid), and soluble protein were evaluated. White LED light was the optimal supplementary light when cultivating Ulva pertusa and Sargassum fusiforme, because it promoted seaweed growth while maintaining protein production. Meanwhile, red LED was unfavored in the cultivation of S. fusiforme, as it affected the seaweed growth and has a lower residual energy ratio underneath the water. LEDs would be a promising supplementary light source for seaweed cultivation.

Highlights

The coastal ecosystem provides a variety of ecosystem goods and services that support the sustainable development for human beings (Bennett et al, 2016; Mehvar et al, 2018; Wu et al, 2020)
Four Light-emitting diodes (LEDs) emitting white, red, green, and blue light were used as artificial light sources for seaweed cultivation, providing 120 μmol photons m−2s−1 on the surface of seaweed thalli
As for S. fusiforme, Specific growth rate (SGR) decreased following the sequence of white LED light (3.21 ± 1.10% d−1) >green and blue LED light (2.44 ± 1.13 and 2.35 ± 0.66% d−1, p > 0.05) >red LED light (1.34 ± 0.39% d−1, p < 0.05)

Summary

Introduction

The coastal ecosystem provides a variety of ecosystem goods and services that support the sustainable development for human beings (Bennett et al, 2016; Mehvar et al, 2018; Wu et al, 2020). Seaweeds cover a large area of the coastal zone, providing highvalue ecosystem services (i.e., globally significant carbon fixation, absorb contaminants, etc.) and raw material for food, fertilizer, and pharmaceutical industries (Capuzzo et al, 2015; Duarte et al, 2017; Xiao et al, 2017; Xiao et al, 2019a; Xiao et al, 2021; Pan et al, 2018). Human activities and global climate change are currently posing a high pressure on the coastal ecosystems (Xiao et al, 2015; Zhao et al, 2017; Smale et al, 2019; Huang et al, 2020; Huang et al, 2021; Tang et al, 2021).

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