6+ January - February 2015
The effect of pH, dark - light cycle and light colour on the chlorophyll
and carotenoid production ofSpirulina sp.
Nguyen Thi Huynh Nhu* and Nguyen Huu Hiep
Biotechnology Research and Development Institute, Can Tho University, Viet Nam
* Correspondent author: email@example.com
Spirulina sp., multicellular filament algae, is helically coiled. This is a rich nutrition microalgae with protein,
carbohydrate, vitamin, chlorophyll and carotenoid. Many researches and applications of Spirulina sp. have been
studied by interested scientists, especially, pigment production. The purpose of this research was determination the
effect of pH, dark – light cycle and light colour on the growth and pigment production of Spirulina sp. The results
showed that pH 9, white light and continuous illumination 24/24 hours were appropriate conditions for biomass
increasing, chlorophyll a, chlorophyll b and carotenoid production in Spirulina sp. At pH 9, biomass and carotenoid
were highest in day 8 (0.16g/ 50mL and 1.43 ?g/mL, respectively). The highest production of chlorophyll a and
chlorophyll b were collected in day 12 (2.72 ?g/mL and 3.35 ?g/mL, respectively). The growth ofSpirulina sp. was
slow at green colour and limited at red colour. Compared to 12/24 hour illumination, growing algae under continuous
illumination 24/24 hour was higher 1.08 times in biomass, 2.36 times in chlorophyll a, 1.2 times in chlorophyll b and 1.7
times in carotenoid content. When white light was applied, continuous illumination 24/24 hour and aeration, pH
remained from 10 to 10.8, then decreased in day 16 and 20 and no significant differences between treatments during the
experiment. Besides, Spirulina ‘s shape recovered quickly in appropriate conditions.
Keywords : biomass, carotenoid, chlorophyll a, chlorophyll b, Spirulina sp.