Background

UV radiation and its impact on living organisms became an essential concern over the past three decades and will be essential in the years to come. So, the present investigation was devoted to examining the impact of artificial UV-B radiation on the accumulation of amino acids and MDA contents as well as some antioxidant enzymes activities in three freshwater cyanobacterial species; Planktothrix cryptovaginata, Nostoc carneum and Microcystis aeruginosa, one freshwater green alga; Scenedesmus acutus and one marine cyanobacterium; Microcystis.

Methods

The algal cultures were exposed directly to artificial UV-B radiation for 1, 3, 5, and 7 hours and amino acids, MDA contents, and the antioxidant enzyme activities; CAT, POD, APX, and SOD were analyzed.

Results

The data obtained indicated that alteration in MDA and antioxidant enzymes by UV stress depends on the algal species and the exposure time. The treatment of the investigated algae with different periods of UV-B exposure stimulated the biosynthesis of some individual amino acids and inhibited the accumulation of some others. In some cases, exposure to UV-B was accompanied by the disappearance of some amino acids. In addition, UV-B exposure for 3 hours stimulated the accumulation of total amino acids in M. aeruginosa and S. acutus, while 7 hours of UV-B enhanced the biosynthesis of total amino acids in M. aeruginosa only from the investigated algae.

Conclusion

Exposure of some cyanobacteria and green algae to UV-B radiation stimulated the biosynthesis of some individual amino acids and inhibited the accumulation or accompanied by the disappearance of some others. However, the alteration in MDA and antioxidant enzymes by UV stress depends on the algal species and the exposure time.

中文翻译：

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UV-B辐射对某些蓝细菌和绿藻的氨基酸谱，抗氧化酶和脂质过氧化的影响。

背景

在过去的三十年中，紫外线辐射及其对活生物体的影响已成为至关重要的问题，并且在未来几年中将至关重要。因此，本研究致力于研究人工紫外线-B辐射对三种淡水蓝藻物种氨基酸和MDA含量的积累以及某些抗氧化酶活性的影响。淡水绿藻之一，Planktothrix cryptovaginata，Nostoc carneum和Microcystis aeruginosa；cut鱼（Scendesmus acutus）和一种海洋蓝细菌；微囊藻。

方法

将藻类培养物直接暴露于人工UV-B辐射1、3、5和7小时，以及氨基酸，MDA含量和抗氧化酶活性；分析了CAT，POD，APX和SOD。

结果

获得的数据表明，紫外线胁迫对MDA和抗氧化酶的改变取决于藻类和暴露时间。用不同的UV-B暴露时间对所研究的藻类进行处理可以刺激某些氨基酸的生物合成，并抑制其他一些氨基酸的积累。在某些情况下，暴露于UV-B伴随着某些氨基酸的消失。此外，UV-B暴露3小时刺激了铜绿假单胞菌和铜cut中总氨基酸的积累，而UV-B 7小时仅从被研究的藻类中增强了铜绿假单胞菌中总氨基酸的生物合成。

结论

某些蓝细菌和绿藻暴露于UV-B辐射会刺激某些氨基酸的生物合成，并抑制某些氨基酸的积累或伴随其他某些氨基酸的消失。但是，紫外线胁迫对MDA和抗氧化酶的改变取决于藻类和暴露时间。