Department of Botany and Microbiology, Acharya Nagarjuna University, Guntur, India.
Department of Botany, Sri Krishnadevaraya University, Ananthapur, India.
Int J Phytoremediation. 2021;23(11):1184-1190. doi: 10.1080/15226514.2021.1884182. Epub 2021 Feb 18.
The rhizobia isolated from root nodules of horse gram were screened for nickel (Ni) tolerance . The strain HGR-4 could tolerate 1000 µg g of Ni. It was also observed that horse gram plants associated with HGR-4 have shown Ni stress tolerance in Ni amended soils up to a concentration of 100 µg g. In another experiment, the plants associated with HGR-4 have shown higher nodulation, nitrogen level, and leghaemoglobin content at 80 µg g of Ni than control plants without HGR-4 inoculation. Analysis of biosorption potential of Ni in horse gram plants inoculated by the strain HGR-4 was done using atomic absorption spectroscopy revealed maximum biosorption in bacterial root nodules. Besides, there was a reduction in the content of the heavy metal in the soil samples which demonstrates a fair amount of heavy metal extraction and accumulation of Ni by rhizobia associated root nodules of the horse gram. This study demonstrates that the strain HGR-4 (GQ483457 sp. ATCC BAA-2335) could be a potential source for phytoextraction of Ni contaminated soils upon its association with horse gram. The study could be of use in phytoremediation of metal (Ni) contaminated soils in the future. The phytoremediation of nickel (Ni) using of rhizobia associated with horse gram remains unevaluated till now. Horse gram associated with rhizobia could produce nodules and fix nitrogen even in Ni amended soils. The biosorption potential of the rhizobial strains was analyzed from both root nodules and soil. These findings imply that horse gram plants associated with these rhizobial strains could be used to remediate Ni metal in contaminated soils.
从马豆根瘤中分离出的根瘤菌进行了镍（Ni）耐受性筛选。菌株 HGR-4 可耐受 1000μg g 的 Ni。还观察到与 HGR-4 相关的马豆植物在添加 Ni 的土壤中表现出 Ni 胁迫耐受性，最高可达 100μg g。在另一个实验中，与 HGR-4 相关的植物在 80μg g 的 Ni 下表现出更高的结瘤、氮水平和豆血红蛋白含量，而没有接种 HGR-4 的对照植物则没有。使用原子吸收光谱法分析接种菌株 HGR-4 的马豆植物对 Ni 的生物吸附潜力，发现细菌根瘤中的生物吸附量最大。此外，土壤样品中重金属含量降低，这表明与马豆根相关的根瘤菌对重金属的提取和积累量相当可观。这项研究表明，菌株 HGR-4（GQ483457 sp. ATCC BAA-2335）可能是与马豆相关的植物提取 Ni 污染土壤的潜在来源。该研究将来可能对受金属（Ni）污染土壤的植物修复有用。目前尚未评估与马豆相关的根瘤菌对镍（Ni）的植物修复作用。与根瘤菌相关的马豆可以在添加 Ni 的土壤中产生根瘤并固定氮。从根瘤和土壤中分析了根瘤菌株的生物吸附潜力。这些发现表明，与这些根瘤菌相关的马豆植物可用于修复污染土壤中的 Ni 金属。
