High production of carotenoids by the green microalga Asterarcys quadricellulare PUMCC 5.1.1 under optimized culture conditions

Abstract

Since carotenoids are important as natural colorants, antioxidants, neutraceutics and pharmaceutics, the aim of the present study was to find a new good source of these pigments. We hereby report a green microalga Asterarcys quadricellulare PUMCC 5.1.1 as a new and good producer of carotenoids. The organism produced 35±1.75 μg carotenoids mg −1 dry biomass during stationary phase in control cultures. The growth and carotenoids production by the test microalga were optimized by varying nutrient growth media, pH, nitrogen and phosphate source, salinity, light quality, intensity and duration. The optimized conditions for carotenoid production were: Bold basal (BB) medium with pH 8.5, containing with10 mM nitrate, 3.5 mM phosphate and 0.17 mM salinity and illuminated with blue light with 60 μmol m -2 s -1 photon flux light intensity. Cultivation of cultures in the above mentioned optimized conditions resulted in nearly 3.0 fold increase in carotenoid production compared to the control cultures grown in unmodified BB medium. Using HPTLC, four carotenoids have been identified as β-carotene, lutein, astaxanthin and canthaxanthin. Further, carotenoids were also separated and purified by flash chromatography and the amounts of purified carotenoids were determined by HPLC. The organism produced 47.0, 28.7, 15.5 and 14.0 μg β-carotene, lutein, astaxanthin and canthaxanthin mg −1 dry biomass, respectively, under optimized conditions. The amount of total carotenoids (118 μg mg -1 dry biomass) produced by Asterarcys quadricellulare PUMCC 5.1.1 under optimized culture conditions was significantly higher than control cultures. Thus, this microalgal strain is a promising candidate for carotenoid production at commercial level.

Identification of microalgae cultured in Bold’s Basal medium from freshwater samples, from a high-rise city

“…Coelastrum sp. and Asterarcys quadricellulare have nutrition and pharmaceutical potential 41 , 42 . Parachlorella beijerinckii is currently employed in the cosmetics industry 43 .…”

Isolation of Industrial Important Bioactive Compounds from Microalgae

“…A continuous search for potential new strains for large-scale production of these pigments are still advancing as the current major strains are still limited to a few species, namely, Spirulina platensis, Haematococcus pluvialis and Chlorella sp. Singh et al [ 136 ] discovered Asterarcys quadricellulare PUMCC 5.1.1 strain, a green microalga with a promising characteristic for carotenoid production while Kaushal et al [ 137 ] reported a new cyanobacterium Nodularia sphaerocarpa PUPCCC 420.1 which produces phycobiliprotein and reckoned as a good candidate for production at commercial scale.…”

Natural Pigments of Microbial Origin

“…Diverse agro-industrial wastes have been investigated for production of the well-known Monascus pigments (Table 1), and some processes using such inexpensive substrates presented high pigment yields (Embaby et al, 2018). In addition, industrial wastewaters are successfully used for production of phycocyanins and carotenoid pigments by microalgae (Singh et al, 2019;Arashiro et al, 2020). Intracellular carotenoids (β-carotene, γ-carotene, torulene, and torularhodin) from Rhodotorula species have been produced by using different agro-industrial byproducts as sugarcane bagasse, wheat bran, rice bran, silage, whey, raw glycerol, corn steep liquor, sugarcane molasses, waste chicken feathers, fruit waste extract, and many others (Sharma and Ghoshal, 2019;Korumilli et al, 2020).…”