CARBON DIOXIDE-INDUCED DELAY OF CELLULAR DEVELOPMENT IN TWO CHLORELLA SPECIES(1)

Area of Science:

• * Microbiology
• * Algology
• * Plant Physiology

Background:

• * Algal cultures are sensitive to environmental conditions.
• * Carbon dioxide (CO2) is a key component in photosynthesis and algal growth.

Purpose of the Study:

• * To investigate the impact of elevated carbon dioxide (CO2) on the cell development of Chlorella species.
• * To determine if light conditions influence the CO2 effect on algal development.

Main Methods:

• * Synchronous cultures of Chlorella fusca and Chlorella vannielii were used.
• * Cultures were gassed with air enriched with varying concentrations of CO2 (1.5% vol. and higher).
• * Cell development was monitored under different light and dark conditions.

Main Results:

• * CO2 concentrations of 1.5% vol. and higher induced a delay in cell development for both Chlorella species.
• * The delay in development was more pronounced when the final developmental stages occurred in the light compared to the dark.
• * Up to 5% vol. CO2 did not reduce dry matter production in continuous light.

Conclusions:

• * Elevated CO2 levels can inhibit cell development in certain Chlorella species.
• * Light intensity plays a role in the inhibitory effect of CO2 on algal development.
• * The inhibitory effect of CO2 may be specific to conditions where nitrate is the sole nitrogen source.