外源2,6-二叔丁基对甲酚对非生物胁迫条件下雨生红球藻虾青素积累的影响

The effects of exogenous butylated hydroxytoluene on astaxanthin accumulation in Haematococcus pluvialis under abiotic stress

摘要:

【背景】雨生红球藻是天然虾青素的最佳来源，广泛应用于虾青素的工业化生产。【目的】探究外源添加不同浓度的2,6-二叔丁基对甲酚(Butylated hydroxytoluene，BHT)对雨生红球藻虾青素积累的影响，以期建立BHT提高雨生红球藻虾青素产量的技术体系。【方法】选用不含硝态氮的BBM培养基，辅以强光照，培养雨生红球藻(Haematococcus pluvialis) LUGU，测试不同浓度BHT对雨生红球藻生物量、虾青素含量、活性氧、抗氧化系统和虾青素合成相关酶基因的影响。【结果】在0?3 mg/L BHT范围内，2 mg/L BHT对雨生红球藻虾青素积累的促进效果最佳，达到31.66 mg/g。2 mg/L BHT有效降低了雨生红球藻内的活性氧水平，增加了细胞内NO水平，提高了藻细胞内过氧化氢酶(Catalase，CAT)、过氧化物酶(Peroxidase，POD)和超氧化物歧化酶(Superoxide dismutase，SOD)活性以及谷胱甘肽(Glutathione，GSH)的含量，诱导了虾青素合成关键酶基因chy和lcy的高效表达。【结论】非生物胁迫条件下，外源添加适量的BHT能促进雨生红球藻中虾青素的积累，且与藻细胞内的信号分子活性氧(Reactive oxygen species，ROS)、NO水平及虾青素合成相关基因的表达调控相关。

Abstract:

[Background] The Haematococcus pluvialis is the best source of natural astaxanthin and is widely used in industrial production of astaxanthin. [Objective] The current study is to explore influences of different concentrations butylated hydroxytoluene (BHT) on accumulation of astaxanthin in H. pluvialis, with a view to build the BHT technology system for enhancing astaxanthin content of H. pluvialis. [Methods] Without nitrate bold’s basal medium was selected as the induction medium for the culture of Haematococcus pluvialis strain LUGU. Meanwhile, high light treatment medium maintained induction conditions. the effects of different concentrations of butylated hydroxytoluene (BHT) on the growth, astaxanthin accumulation, reactive oxygen species, antioxidant system and the expression of related gene were studied in Haematococcus pluvialis under high light and nitrogen deficiency. [Results] The results showed that the astaxanthin content was enhanced efficiently in alga cells treated with 2mg/L BHT, within the range of 0–3 mg/L BHT, reaching 31.66 mg/g. In addition, 2 mg/L BHT treatment group effectively reduces the level of reactive oxygen species, increases intracellular nitric oxide levels, improves the algal cells catalase (CAT), peroxidase (POD), superoxide dismutase (SOD) activity and glutathione (GSH) content, inducing efficient expression of lcy and chy. [Conclusion] Under abiotic stress conditions, exogenous BHT could promote astaxanthin accumulation, which was associated with BHT mediating the levels of ROS and NO, and astaxanthin biosynthetic related genes expressions in H. pluvialis.