Rodriguez Irene B, Ho Tung-Yuan
Research Center for Environmental Changes, Academia Sinica, Taipei, Taiwan.
Sci Rep. 2014 Mar 24;4:4445. doi: 10.1038/srep04445.
Trichodesmium, a nonheterocystous cyanobacterium widely abundant in the surface water of the tropical and subtropical ocean, fixes dinitrogen under high light conditions while concurrently undergoing photosynthesis. The new production considerably influences the cycling of nitrogen and carbon in the ocean. Here, we investigated how light intensity and nickel (Ni) availability interplay to control daily rates and diel patterns of N2 fixation in Trichodesmium. We found that increasing Ni concentration increased N2 fixation rates by up to 30-fold in the high light treatment. Cultures subjected to high Ni and light levels fixed nitrogen throughout most of the 24 H light:dark regime with the highest rate coinciding with the end of the 12 H light period. Our study demonstrates the importance of Ni on nitrogen fixation rates for Trichodesmium under high light conditions.
束毛藻是一种广泛存在于热带和亚热带海洋表层水中的非异形胞蓝细菌，在高光条件下进行光合作用的同时固定氮气。这种新的生产力对海洋中氮和碳的循环有很大影响。在此，我们研究了光照强度和镍（Ni）的可利用性如何相互作用，以控制束毛藻中氮气固定的日速率和昼夜模式。我们发现，在高光处理中，镍浓度的增加使氮气固定速率提高了30倍。处于高镍和高光水平的培养物在24小时光照：黑暗周期的大部分时间内都能固定氮，最高速率与12小时光照期结束时一致。我们的研究证明了镍在高光条件下对束毛藻固氮速率的重要性。
