Laboratory of Microbial Genetics, Department of Botany, Institute of Science, Banaras Hindu University, Varanasi, 221005, India.
Department of Botany, University of Lucknow, Lucknow, 226007, India.
Curr Microbiol. 2023 Jul 1;80(8):265. doi: 10.1007/s00284-023-03374-1.
Sulfur is an important key nutrient required for the growth and development of cyanobacteria. Several reports showed the effect of sulfate limitation in unicellular and filamentous cyanobacteria, but such studies have not yet been reported in heterocytous cyanobacteria to ascribe the mechanisms of nitrogen and thiol metabolisms. Thus, the present work was carried out to appraise the impacts of sulfate limitation on nitrogen and thiol metabolisms in Anabaena sp. PCC 7120 by analyzing the contents as well as enzymes of nitrogen and thiol metabolisms. Cells of Anabaena sp. PCC 7120 were exposed to different regimes of sulfate, i.e., 300, 30, 3, and 0 µM. Application of reduced concentration of sulfate showed negative impact on the cyanobacterium. Sulfate-limiting conditions reduces nitrogen-containing compounds in the cells of Anabaena. Additionally, reduced activities of nitrogen metabolic enzymes represented the role of sulfate in nitrogen metabolism. However, decreased activities of thiol metabolic enzymes indicated that sulfate-limited cyanobacterial cells have lower amount of glutathione and total thiol contents. Reduced accumulation of thiol components in the stressed cells indicated that sulfate-limited cells have lower ability to withstand stressful condition. Hence, Anabaena displays differential response to different concentrations of sulfate, and thus, stipulated that sulfur plays an important role in nitrogen and thiol metabolisms. To the best of our knowledge, this is the first report demonstrating the impact of sulfate stress on nitrogen and redox metabolisms in heterocytous cyanobacteria. This preliminary study provides a baseline idea that may help improve the production of paddy.
硫是蓝细菌生长和发育所必需的重要关键营养物质。有几项报告表明硫酸盐限制对单细胞和丝状蓝细菌的影响，但在异形胞蓝细菌中，尚未有关于归因于氮和硫醇代谢机制的此类研究。因此，本工作通过分析氮和硫醇代谢物的含量和酶，评估硫酸盐限制对 Anabaena sp. PCC 7120 氮和硫醇代谢的影响。将 Anabaena sp. PCC 7120 的细胞暴露于不同硫酸盐条件下，即 300、30、3 和 0 µM。硫酸盐浓度降低对蓝细菌有负面影响。硫酸盐限制条件降低了蓝藻细胞中的含氮化合物。此外，氮代谢酶活性降低表明硫酸盐在氮代谢中的作用。然而，硫醇代谢酶活性的降低表明硫酸盐限制的蓝细菌细胞中谷胱甘肽和总硫醇含量较低。在应激细胞中硫醇成分积累减少表明硫酸盐限制的细胞对胁迫条件的抵抗力较低。因此，Anabaena 对不同浓度的硫酸盐表现出不同的反应，这表明硫在氮和硫醇代谢中起重要作用。据我们所知，这是首次报道硫酸盐胁迫对异形胞蓝细菌氮和氧化还原代谢的影响。这项初步研究提供了一个基准想法，可能有助于提高稻田的产量。
