Department of Botany, Punjabi University, Patiala, Punjab, India.
Department of Biotechnology, Punjabi University, Patiala, Punjab, India.
PLoS One. 2019 Sep 6;14(9):e0221930. doi: 10.1371/journal.pone.0221930. eCollection 2019.
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.
由于类胡萝卜素是天然色素、抗氧化剂、营养保健品和药物制剂的重要组成部分，本研究旨在寻找这些色素的新的良好来源。我们在此报告一种新的良好产类胡萝卜素的微藻——四角弯柱藻（ Asterarcys quadricellulare ）PUMCC 5.1.1。该生物在对照培养物的静止期每毫克干生物量可产生 35±1.75 微克类胡萝卜素。通过改变营养生长培养基、pH 值、氮源和磷源、盐度、光质、强度和时间来优化测试微藻的生长和类胡萝卜素的生产。优化类胡萝卜素生产的条件为：pH8.5 的 Bold 基本培养基（BB），含有 10mM 硝酸盐、3.5mM 磷酸盐和 0.17mM 盐度，用 60 μmol m-2 s-1 光子通量的蓝光照射。与在未改良的 BB 培养基中生长的对照培养物相比，在上述优化条件下培养的培养物的类胡萝卜素产量增加了近 3 倍。使用 HPTLC，鉴定出四种类胡萝卜素为β-胡萝卜素、叶黄素、虾青素和角黄素。此外，还通过快速色谱法分离和纯化类胡萝卜素，并通过 HPLC 测定纯化类胡萝卜素的量。在优化条件下，该生物分别产生 47.0、28.7、15.5 和 14.0μgβ-胡萝卜素、叶黄素、虾青素和角黄素mg-1干生物量。在优化培养条件下，四角弯柱藻（ Asterarcys quadricellulare ）PUMCC 5.1.1 产生的总类胡萝卜素（118μgmg-1干生物量）的量明显高于对照培养物。因此，这种微藻菌株是在商业水平上生产类胡萝卜素的有前途的候选物。
