Cellular response of Parachlorella kessleri to a solid surface culture environment

Area of Science:

• Biotechnology
• Photosynthesis research
• Algal cultivation

Background:

• Attached culture systems offer high biomass productivity with reduced space and medium requirements.
• Understanding cellular responses to solid-surface cultivation is crucial for optimizing algal biomass production.

Purpose of the Study:

• Investigate photosynthetic and transcriptomic changes in Parachlorella kessleri upon transfer to solid surfaces.
• Elucidate physiological and gene-expression mechanisms behind vigorous proliferation in attached cultures.

Main Methods:

• Utilized Pulse Amplitude Modulation (PAM) analysis to assess photosynthetic efficiency (PSII quantum yield, photochemical and non-photochemical quenching).
• Measured chlorophyll content over time post-transfer.
• Performed RNA-sequencing (RNA-Seq) to analyze gene expression profiles.

Main Results:

• Chlorophyll content and effective PSII quantum yield temporarily decreased post-transfer, with recovery within 24 hours.
• Non-photochemical quenching increased, indicating light energy dissipation for photoprotection.
• RNA-Seq revealed temporary upregulation of genes involved in photosynthesis, amino acid synthesis, stress response, and ribosomal proteins.

Conclusions:

• Parachlorella kessleri cells experience immediate stress upon transfer to solid surfaces but acclimate within 24 hours.
• Adaptation involves temporary downregulation of photosynthetic machinery and induction of stress response mechanisms.
• Optimized metabolic flow and photosynthetic activity are restored through physiological and transcriptomic regulation.