The effect of carbon dioxide and concentration of nitrate on the growth of harmful algae Cochlodinium Polykrikoides indoor culture

• Main Author: Azuwel Nadzir
• Format: Academic Exercise
• Language: English
• Published: 2008
• Subjects: QK Botany
• Online Access: https://eprints.ums.edu.my/id/eprint/20686/1/The%20effect%20of%20carbon%20dioxide.pdf; https://eprints.ums.edu.my/id/eprint/20686/

Study on the effects of nitrate concentration and CO₂ on the growth of C. polykrikoides was conducted in laboratory under controlled conditions. In this experiment, C. polykrikoides was cultured at four different concentration of nitrate [4.41 x 10⁻⁴ M, 8.82 x 10⁻⁴ M (control), 9.41 x 10⁻⁴ M, 1.09 x 10⁻³] under two different conditions which are with and without CO₂ enrichment. The experiments were conducted under constant light intensity (100 µmolm ⁻²s⁻¹) at 25°C and under a 12 h light: 12 h dark cycle. Cells were incubated for two weeks and samplings were done for growth determination at every one day interval. This study shows that C. polykrikoides reached the maximum density (1200 cells/mL) when grown at 9.41 x 10⁻⁴ M of nitrate concentration and without CO₂ enrichment. However, in CO₂ enriched media, the cells density is relatively very low where at the same concentration of nitrate, cell density was only about 35 cells/mL. These differences outcomes might due to pH changes. Cell densities of C. polykrikoides were low when pH extremely decreased (< 6.50) and at higher pH (> 9.00) under CO₂ enriched media. 2-Way ANOVA analysis indicated that the nitrate concentration, CO₂ and nitrate* CO₂have significant effect (P < 0.05) on the growth of C. polykrikoides.