Ahmed Faruq, Schenk Peer M
Algae Biotechnology Laboratory, School of Agriculture and Food Sciences, The University of Queensland, Brisbane, Queensland 4072, Australia; Centre for Marine Bioproducts Development, Faculty of Medicine, Nursing and Health Sciences, Flinders University, Registry Road, Bedford Park, South Australia 5042, Australia.
Algae Biotechnology Laboratory, School of Agriculture and Food Sciences, The University of Queensland, Brisbane, Queensland 4072, Australia.
Phytochemistry. 2017 Jul;139:25-32. doi: 10.1016/j.phytochem.2017.04.002. Epub 2017 Apr 10.
Plant sterols have become well-known to promote cardiovascular health through the reduction of low density lipoprotein cholesterol in the blood. Plant sterols also have anti-inflammatory, anti-cancer, anti-oxidative and anti-atherogenicity activities. Microalgae have the potential to become a useful alternative source of plant sterols with several species reported to have higher concentrations than current commercial ones. In order to increase phytosterol production and optimise culture conditions, the high sterol producer Pavlova lutheri was treated in different dosages (50-250 mJ m) of UV-C radiation and several concentrations (1-500 μmol/L) of hydrogen peroxide (HO) and the sterol contents were quantified for two days after the treatments. The contents of malondialdehyde (MDA) superoxide dismutase (SOD) as indications of cell membrane damage by lipid peroxidation and repair of oxidative stress, respectively, were measured. Higher activities of SOD and MDA were observed in the treated biomass when compared to the controls. Total sterols increased in P. lutheri due to UV-C radiation (at 100 mJ m) but not in response to HO treatment. Among the nineteen sterol compounds identified in P. lutheri, poriferasterol, epicampesterol, methylergostenol, fungisterol, dihydrochondrillasterol, and chondrillasterol increased due to UV-C radiation. Therefore, UV-C radiation can be a useful tool to boost industrial phytosterol production from P. lutheri.
植物甾醇已因可降低血液中低密度脂蛋白胆固醇从而促进心血管健康而广为人知。植物甾醇还具有抗炎、抗癌、抗氧化和抗动脉粥样硬化活性。微藻有潜力成为植物甾醇的一种有用替代来源，据报道有几个物种的植物甾醇浓度高于目前的商业品种。为了提高植物甾醇产量并优化培养条件，对高产甾醇的鲁氏巴夫藻用不同剂量（50 - 250 mJ/m²）的UV - C辐射以及几种浓度（1 - 500 μmol/L）的过氧化氢（H₂O₂）进行处理，并在处理后两天对甾醇含量进行定量。分别测定了丙二醛（MDA）和超氧化物歧化酶（SOD）的含量，作为脂质过氧化对细胞膜损伤和氧化应激修复的指标。与对照相比，处理后的生物量中观察到更高的SOD和MDA活性。UV - C辐射（100 mJ/m²）使鲁氏巴夫藻中的总甾醇增加，但过氧化氢处理没有此效果。在鲁氏巴夫藻中鉴定出的19种甾醇化合物中，紫海绵甾醇、表油菜甾醇、甲基麦角甾烯醇、真菌甾醇、二氢软海绵甾醇和软海绵甾醇因UV - C辐射而增加。因此，UV - C辐射可以成为提高鲁氏巴夫藻工业植物甾醇产量的有用工具。
