Unravelling the impact of nitrogen deprivation on the morphology and nanomechanical properties of Parachlorella kessleri
Abstract
Nitrogen deprivation is commonly applied to enhance lipid accumulation in microalgae for third-generation biofuel production. However, its influence on cell wall morphology and nanomechanical properties, which critically affect downstream processing, remains poorly explored. To address this gap, this study investigated the impact of nitrogen deprivation on these properties of the freshwater microalga Parachlorella kessleri using a multi-microscopy approach. Starvation did not lead to any significant morphological changes in either cell size (diameter and height) or cell wall thickness, but it significantly impacted nanomechanical properties: the Young's modulus decreased by approximately 60% (from 1320.7 ± 415.1 to 535.8 ± 346.5 kPa), while surface roughness remained comparable between conditions (1.3 ± 0.5 and 1.9 ± 1.4 nm). Regardless of these similar roughness values, starved cells showed a strong negative correlation between roughness and stiffness, suggesting underlying structural changes not captured by morphology alone. Although biomass freezing for storage and subsequent thawing for analysis may have influenced absolute mechanical values, the comparative trends observed indicate that nitrogen deprivation preconditions the structural and nanomechanical features of this microalga. Therefore, this work highlights the potential of nanomechanical descriptors as complementary indicators for evaluating biomass processability in biofuel and bioproduct applications, opening the door to the development of more efficient and subsequently cost-effective cell disruption strategies.
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BibTeX
@article{zurita2026unravelling,
title = {{Unravelling the impact of nitrogen deprivation on the morphology and nanomechanical properties of Parachlorella kessleri}},
author = {Alba Zurita and Simona Sebastiano and Jordan Prieto and Jérémy Pruvost and Mariana Titica and Esther Torrens and Cécile Formosa-Dague and Christophe Bengoa},
journal = {Journal of Applied Phycology},
year = {2026},
month = sep,
doi = {10.1007/s10811-026-04012-6},
url = {https://hal.science/hal-05856934v1},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Unravelling the impact of nitrogen deprivation on the morphology and nanomechanical properties of Parachlorella kessleri
AU - Alba Zurita
AU - Simona Sebastiano
AU - Jordan Prieto
AU - Jérémy Pruvost
AU - Mariana Titica
AU - Esther Torrens
AU - Cécile Formosa-Dague
AU - Christophe Bengoa
PY - 2026
DA - 2026/09/16
JO - Journal of Applied Phycology
DO - 10.1007/s10811-026-04012-6
UR - https://hal.science/hal-05856934v1
AB - Nitrogen deprivation is commonly applied to enhance lipid accumulation in microalgae for third-generation biofuel production. However, its influence on cell wall morphology and nanomechanical properties, which critically affect downstream processing, remains poorly explored. To address this gap, this study investigated the impact of nitrogen deprivation on these properties of the freshwater microalga Parachlorella kessleri using a multi-microscopy approach. Starvation did not lead to any significant morphological changes in either cell size (diameter and height) or cell wall thickness, but it significantly impacted nanomechanical properties: the Young's modulus decreased by approximately 60% (from 1320.7 ± 415.1 to 535.8 ± 346.5 kPa), while surface roughness remained comparable between conditions (1.3 ± 0.5 and 1.9 ± 1.4 nm). Regardless of these similar roughness values, starved cells showed a strong negative correlation between roughness and stiffness, suggesting underlying structural changes not captured by morphology alone. Although biomass freezing for storage and subsequent thawing for analysis may have influenced absolute mechanical values, the comparative trends observed indicate that nitrogen deprivation preconditions the structural and nanomechanical features of this microalga. Therefore, this work highlights the potential of nanomechanical descriptors as complementary indicators for evaluating biomass processability in biofuel and bioproduct applications, opening the door to the development of more efficient and subsequently cost-effective cell disruption strategies.
SN - 0921-8971
SN - 1573-5176
ER -