Key Laboratory of Integrated Management of Crop Diseases and Pests, Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Nanjing, 210095, China.
Key Laboratory of Integrated Management of Crop Diseases and Pests, Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Nanjing, 210095, China.
Chemosphere. 2022 Sep;303(Pt 3):135206. doi: 10.1016/j.chemosphere.2022.135206. Epub 2022 Jun 2.
Heavy metal remediation, such as cadmium (Cd) by microbial strains is efficient and environment-friendly. In this current study, we exploited the potential of Bacillus strains (Cd-tolerant; NMTD17, GBSW22, and LLTC96) to regulate Cd biosorption mechanisms and improve rice seedling growth. The results showed that initial concentration and contact time affected Cd biosorption, and the kinetic models of pseudo orders were effective in the elaborate biosorption process. Mainly, the bacterial cell wall had the potential for Cd biosorption, and we found non-significant biosorption alterations among bacterial strains' inner and outer surfaces of cell membranes. Furthermore, the Fourier transform infrared (FTIR) spectroscopy analysis identified the differences in functional groups, such as C-N, PO, -SO, CO, COOH, C-O, C-N, -OH, and -NH that interact in biosorption by Bacillus strains. The scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) examination revealed that the binding of Cd to microbes was mostly based on ion exchange pathways. Moreover, the Bacillus strains responded to Cd stress in rice under pot experiment at various concentrations (0, 0.25, and 0.50 mg kg), and they also influenced the chlorophyll contents and antioxidants activities were studied. The analysis of physio-morphological parameters was observed to be increased, which indicated that all Bacillus strains showed significant effects on rice growth under Cd stress. These results revealed that the selected strains had the capability for additional use in the development of Cd bioremediation methods. These strains also provided plant growth-promoting (PGP) traits that can alleviate the harmful effects of Cd in rice plants.
重金属修复，如微生物菌株对镉（Cd）的修复，既高效又环保。在本研究中，我们利用芽孢杆菌菌株（耐镉；NMTD17、GBSW22 和 LLTC96）的潜力来调节镉的生物吸附机制并改善水稻幼苗的生长。结果表明，初始浓度和接触时间影响镉的生物吸附，准一级动力学模型在详细的生物吸附过程中是有效的。主要的是，细菌细胞壁具有镉生物吸附的潜力，我们发现细菌细胞膜内外表面的生物吸附没有明显的变化。此外，傅里叶变换红外（FTIR）光谱分析确定了功能基团的差异，如 C-N、PO、-SO、CO、COOH、C-O、C-N、-OH 和 -NH，这些基团在芽孢杆菌菌株的生物吸附中相互作用。扫描电子显微镜-能量色散光谱（SEM-EDS）检查表明，Cd 与微生物的结合主要基于离子交换途径。此外，在不同浓度（0、0.25 和 0.50mgkg）的盆栽试验中，芽孢杆菌菌株对水稻中的 Cd 胁迫做出了响应，并且还研究了它们对叶绿素含量和抗氧化剂活性的影响。观察到生理形态参数的分析增加了，这表明所有芽孢杆菌菌株在 Cd 胁迫下对水稻生长都有显著的影响。这些结果表明，所选菌株具有在开发 Cd 生物修复方法方面的额外应用能力。这些菌株还提供了植物生长促进（PGP）特性，可以减轻 Cd 对水稻植株的有害影响。
