TY - JOUR

T1 - Impact of green and blue-green light on the growth, pigment concentration, and fatty acid unsaturation in the microalga Monoraphidium braunii

AU - Helamieh, Mark

AU - Reich, Marco

AU - Rohne, Philipp

AU - Riebesell, Ulf

AU - Kerner, Martin

AU - Kümmerer, Klaus

N1 - Funding Information: This study was funded by the research initiative Zukunft Bau of the Federal Institute for Research on Building, Urban Affairs, and Spatial Development (No. SWD‐10.08.18.7‐17.02). A special thanks to Christoph Stegen of the technical support team of the Leuphana University Lüneburg for his excellent technical support and expertise to optimize the experimental setup for microalgae cultivation. We thank Kerstin Nachtigall of the GEOMAR Helmholtz Centre for Ocean Research Kiel, for performing the HPLC‐DAD analysis. Finally, we also thank Stina Krings for her contribution to microalgae cultivation and sampling. Open Access funding enabled and organized by Projekt DEAL. Publisher Copyright: © 2023 The Authors. Photochemistry and Photobiology published by Wiley Periodicals LLC on behalf of American Society for Photobiology.

PY - 2023/10/26

Y1 - 2023/10/26

N2 - The spectral composition of light is an important factor for the metabolism of photosynthetic organisms. Several blue light-regulated metabolic processes have already been identified in the industrially relevant microalga Monoraphidium braunii. However, little is known about the spectral impact on this species' growth, fatty acid (FA), and pigment composition. In this study, M. braunii was cultivated under different light spectra (white light: 400–700 nm, blue light: 400–550 nm, green light: 450–600 nm, and red light: 580–700 nm) at 25°C for 96 h. The growth was monitored daily. Additionally, the FA composition, and pigment concentration was analyzed after 96 h. The highest biomass production was observed upon white light and red light irradiation. However, green light also led to comparably high biomass production, fueling the scientific debate about the contribution of weakly absorbed light wavelengths to microalgal biomass production. All light spectra (white, blue, and green) that comprised blue-green light (450–550 nm) led to a higher degree of FA unsaturation and a greater concentration of all identified pigments than red light. These results further contribute to the growing understanding that blue-green light is an essential trigger for maximized pigment concentration and FA unsaturation in green microalgae.

AB - The spectral composition of light is an important factor for the metabolism of photosynthetic organisms. Several blue light-regulated metabolic processes have already been identified in the industrially relevant microalga Monoraphidium braunii. However, little is known about the spectral impact on this species' growth, fatty acid (FA), and pigment composition. In this study, M. braunii was cultivated under different light spectra (white light: 400–700 nm, blue light: 400–550 nm, green light: 450–600 nm, and red light: 580–700 nm) at 25°C for 96 h. The growth was monitored daily. Additionally, the FA composition, and pigment concentration was analyzed after 96 h. The highest biomass production was observed upon white light and red light irradiation. However, green light also led to comparably high biomass production, fueling the scientific debate about the contribution of weakly absorbed light wavelengths to microalgal biomass production. All light spectra (white, blue, and green) that comprised blue-green light (450–550 nm) led to a higher degree of FA unsaturation and a greater concentration of all identified pigments than red light. These results further contribute to the growing understanding that blue-green light is an essential trigger for maximized pigment concentration and FA unsaturation in green microalgae.

KW - algal metabolism

KW - fatty acid desaturase

KW - green microalgae

KW - photosynthetic pigment

KW - polyunsaturated fatty acid

KW - spectral light composition

KW - thylakoid membrane

KW - Chemistry

UR - http://www.scopus.com/inward/record.url?scp=85174831923&partnerID=8YFLogxK

UR - https://www.mendeley.com/catalogue/3c7b3409-8dfb-3d3c-abc5-f100d6710feb/

U2 - 10.1111/php.13873

DO - 10.1111/php.13873

M3 - Journal articles

C2 - 37882377

AN - SCOPUS:85174831923

JO - Photochemistry and Photobiology

JF - Photochemistry and Photobiology

SN - 0031-8655

ER -