Comparative Response of Marine Microalgae to H₂O₂-Induced Oxidative Stress

Area of Science:

• Marine biotechnology
• Microalgal cultivation
• Biochemical analysis

Background:

• Growing interest in marine microalgae for bioactive compounds (pigments, omega-3 fatty acids, antioxidants).
• Applications in nutraceutical and cosmetic industries.
• Need for controlled methods to modulate metabolite production.

Purpose of the Study:

• To comparatively assess the effects of hydrogen peroxide (H2O2) on five marine microalgal species.
• To investigate H2O2-induced metabolic changes and bioactive compound yields.
• To determine species-specific responses to oxidative stress.

Main Methods:

• Batch cultivation of five microalgal species: Amphidinium carterae, Brachiomonas submarina, Stauroneis sp., Diacronema sp., and Rhodella violacea.
• Exposure to hydrogen peroxide (H2O2) during growth.
• Analysis of antioxidant activity (DPPH assay), pigment content, and fatty acid profiles.

Main Results:

• Species-specific alterations in antioxidant activity, pigment yields (lutein, chlorophyll b, fucoxanthin), and fatty acid composition (saturated C16/C18, EPA).
• Amphidinium carterae and Brachiomonas submarina showed enhanced antioxidant responses.
• Diacronema sp. exhibited reduced antioxidant response and fucoxanthin, while Rhodella violacea showed increased EPA.

Conclusions:

• Hydrogen peroxide (H2O2) can be utilized as a stressor to induce metabolic changes in microalgae.
• Observed responses to H2O2 are highly species-specific.
• Further optimization of H2O2 dosage is required for targeted metabolite yield modulation in individual species.