[关键词]
[摘要]
本研究探讨了Mn2+、Cu2+、Na+、Ca2+、Mg2+、Ba2+、Al3+等金属离子和高锰酸钾、过氧化氢等氧化物对北冬虫夏草类胡萝卜素累积和超氧化物歧化酶(SOD)活性的影响,结果表明Mn2+、Cu2+以及高浓度的Mg2+对蛹虫草类胡萝卜素的积累起到抑制作用;Na+、Ca2+、Ba2+、Al3+和低浓度的Mg2+则能促进类胡萝卜素的积累;低浓度的高锰酸钾和中高浓度的过氧化氢对类胡萝卜素的积累起抑制作用;0.3%、0.4%的高锰酸钾和1%的过氧化氢能促进类胡萝卜素的积累。其中促进北冬虫夏草类胡萝卜素积累效果最好的是2%的Mg2+,该胁迫条件下类胡萝卜素产量达到279.21 μg/g,比空白对照组提升了184.9%。Mn2+、Ba2+、Al3+在低浓度时提高SOD活性,高浓度时降低SOD活性,当浓度均为3%时,SOD活性最高;Cu2+则相反,在低浓度时抑制SOD活性,高浓度时提高SOD活性;Ca2+、Mg2+对SOD的影响较为复杂,随着浓度升高,SOD活性先升高再下降再升高,SOD酶活性峰值均出现在离子浓度为1%处;Na+对SOD活性整体影响不大;高锰酸钾明显促进SOD酶的活性,而过氧化氢明显抑制SOD酶活。其中促进北冬虫夏草SOD酶活效果最好的是3%的Al3+,该胁迫条件下SOD酶活达到167.62 U/g,比空白对照组提升了4.82倍。研究结果显示,金属离子和氧化物等胁迫因子能够引起北冬虫夏草抗氧化系的应激反应并在一定程度上提高抗氧化物质累积量,这为利用北冬虫夏草菌丝体发酵生产抗氧化物质奠定实验基础。
[Key word]
[Abstract]
In this study, the effects of metal ions such as Mn2+, Cu2+, Na+, Ca2+, Mg2+, Ba2+, Al3+ and oxides such as potassium permanganate, hydrogen peroxide on the accumulation of carotenoids and the enzyme activity of superoxide dismutase (SOD) in Cordyceps militaris were investigated. The results showed that the accumulation of carotenoids in C. militaris was inhibited by Mn2+, Cu2+, and Mg2+ at a high concentration, but promoted by Na+, Ca2+, Ba2+, Al3+, and Mg2+ at a low concentration. The accumulation of carotenoids in C. militaris was inhibited by potassium permanganate at a low concentration and hydrogen peroxide at a medium-high concentration, but promoted by potassium permanganate at 3% and 4% and hydrogen peroxide at 1%. Among which, Mg2+ at 2% promoted the greatest carotenoid accumulation in C. militaris. Under this stress condition, the carotenoid production reached 279.21 μg/g (an increase by 184.9% compared with the control group). The activity of SOD was increased by Mn2+ Ba2+ and Al3+ at low concentrations, but decreased by them at high concentrations, with the highest SOD activity occurring at the concentration of 3%. In contrast, the activity of SOD was inhibited by Cu2+ at low concentrations but increased at high concentrations. The effects of Ca2+ and Mg2+ on SOD were complicated. With an increase in their concentrations, the activity of SOD was increased initially, then decreased and finally increased, with the peak SOD activity occurring at the concentration of 1%. In general, Na+ had little effect on SOD. The activity of SOD was promoted significantly by potassium permanganate, but inhibited by hydrogen peroxide significantly. Al3+ at 3% was the most effective to promote carotenoid accumulation in C. militaris. Under this stress condition, the activity of SOD reached 167.62 U/g (increased by 4.82 times compared with the control group). The research results showed that the stress factors including metal ions and oxides could induce the stress responses of the antioxidant system in C. militaris and increase the accumulation of antioxidants to a certain extent. These results have laid an experimental foundation for using C. militaris mycelium to produce antioxidants via fermentation.
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[基金项目]
国家自然科学基金项目(31801918,31772373);广东省现代农业产业技术体系创新团队建设项目(食用菌)(2019KJ103);广东省自然科学基金(2016A030313404);北京工商大学中加食品营养与健康联合实验室开放课题基金资助课题