A method for obtaining plastid pigments from the biomass of Chlorella microalgae
Peter the Great St. Petersburg Polytechnic University, Graduate School of Biotechnology and Food Science, Polytechnicheskaya, 29, RU195251, St. Petersburg, Russia
Microalgae are distinguished from land plants by the high content of plastid pigments and the biodiversity of carotenoids. The aim of this study is to develop a technology for extracting a pigment complex from the biomass of the microalgae of the genus Chlorella and to determine the extracted pigments’ composition. To obtain biomass, a crude cell suspension of microalgae was used, which was obtained under laboratory conditions for pre-culture cultivation of C. sorokiniana (strain 211-8k). The extraction of plastid pigments from air-dry biomass after disintegration of cell membrane was performed in the 40 kHz mode. It was found that the highest pigment content in ethanol extracts was observed after 30 min (870.0 ± 27.1 mg L-1) at 45−50 °C. The pigments’ composition in the resulting total extracts was determined by spectrophotometry and the Reverse Phase HPLC method. The established content of chlorophyll a in the obtained extracts was 537.5 ± 10.0 mg L-1, the content of chlorophyll b was 182.5 ± 27.5 mg L-1; the maximum output of the amount of carotenoids in extracts was 150.0 ± 10.0 mg L-1. Thus, the main identified forms of carotenoids in extracts from the biomass of microalgae C. sorokiniana were xanthophylls: lutein and fucoxanthin (18.6 and 4.7% of the amount of pigment in extract, respectively) and β-carotene (1.8% of the amount of pigment). It is planned to further fractionate the obtained total extracts of the pigment complex to obtain various forms of chlorophylls and carotenoids to study the spectrum of physiological activity of plastid pigments.