Zhang Hui, Song Lin, Chen Xiaolin, Li Pengcheng
College of Marine Science and Biological Engineering, Qingdao University of Science and Technology, Qingdao 266042, China.
CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China.
Molecules. 2021 Jun 3;26(11):3390. doi: 10.3390/molecules26113390.
Excessive use of nitrogen fertilizer in intensively managed agriculture has resulted in abundant accumulation of nitrate in soil, which limits agriculture sustainability. How to reduce nitrate content is the key to alleviate secondary soil salinization. However, the microorganisms used in soil remediation cause some problems such as weak efficiency and short survival time. In this study, seaweed polysaccharides were used as stimulant to promote the rapid growth and safer nitrate removal of denitrifying bacteria. Firstly, the growth rate and NO-N removal capacity of three kinds of denitrifying bacteria, (BS), (PS) and (PP), were compared. The results showed that (BS) had a faster growth rate and stronger nitrate removal ability. We then studied the effects of polysaccharides (EP), carrageenan (CA), and sodium alginate (AL) on growth and denitrification performance of (BS). The results showed that seaweed polysaccharides obviously promoted the growth of (BS), and accelerated the reduction of NO-N. More importantly, the increased NH-N content could avoid excessive loss of nitrogen, and less NO-N accumulation could avoid toxic effects on plants. This new strategy of using denitrifying bacteria for safely remediating secondary soil salinization has a great significance.
集约化农业中过量使用氮肥导致土壤中硝酸盐大量积累，这限制了农业的可持续性。如何降低硝酸盐含量是缓解土壤次生盐渍化的关键。然而，用于土壤修复的微生物存在一些问题，如效率低下和存活时间短。在本研究中，海藻多糖被用作刺激剂，以促进反硝化细菌的快速生长和更安全地去除硝酸盐。首先，比较了三种反硝化细菌，即芽孢杆菌（BS）、假单胞菌（PS）和副球菌（PP）的生长速率和NO-N去除能力。结果表明，芽孢杆菌（BS）生长速率更快，硝酸盐去除能力更强。然后，研究了岩藻多糖（EP）、卡拉胶（CA）和海藻酸钠（AL）对芽孢杆菌（BS）生长和反硝化性能的影响。结果表明，海藻多糖明显促进了芽孢杆菌（BS）的生长，并加速了NO-N的还原。更重要的是，增加的NH-N含量可以避免氮的过度流失，较少的NO-N积累可以避免对植物的毒性作用。这种利用反硝化细菌安全修复土壤次生盐渍化的新策略具有重要意义。
