Zaidi Sabina, Usmani Saima, Singh Braj Raj, Musarrat Javed
Department of Agricultural Microbiology, Faculty of Agricultural Sciences, Aligarh Muslim University (AMU), Aligarh 202 002, India.
Chemosphere. 2006 Aug;64(6):991-7. doi: 10.1016/j.chemosphere.2005.12.057. Epub 2006 Feb 17.
In this study, a nickel (Ni)-tolerant Bacillus subtilis strain SJ-101 was characterized based on the 16SrDNA homology and phylogenetic analysis. The role of this strain ascertained in facilitating Ni accumulation in the Indian mustard plant (Brassica juncea [L]. Czern and Coss) var. Pusa Bold (DIR-50), to elucidate the potential of Ni phytoremediation in combination with metal-tolerant rhizobacteria. The data revealed that the plants exposed to NiCl2 (1750 mg kg(-1)) in soil bioaugmented with strain SJ-101 have accumulated 0.147% Ni vis-à-vis 0.094% accumulation in dry biomass of the plants grown in uninoculated soil. The strain SJ-101 has also exhibited the capability of producing indole acetic acid (IAA) (55 microg ml(-1)), and solubilizing inorganic phosphate (90 microg ml(-1)) in specific culture media. The pot culture experiments clearly demonstrated the beneficial effects of bioinoculant strain SJ-101 with significant increase (p<0.05) in the plant growth attributes in untreated control soil. Furthermore, the protective effect of the strain SJ-101 against Ni phytotoxicity was evident in plants grown in soil treated with NiCl2 in concentration range of 250-1750 mg kg(-1). Thus, it is suggested that the strain SJ-101 owing to its intrinsic abilities of plant growth promotion, and attenuation of soil Ni by biosorption and bioaccumulation, could be exploited for bacteria-assisted phytoaccumulation of this toxic heavy metal from contaminated sites.
在本研究中，基于16SrDNA同源性和系统发育分析对一株耐镍枯草芽孢杆菌SJ - 101进行了特性鉴定。确定了该菌株在促进印度芥菜（Brassica juncea [L]. Czern and Coss）品种Pusa Bold（DIR - 50）中镍积累方面的作用，以阐明镍与耐金属根际细菌联合进行植物修复的潜力。数据显示，在添加了菌株SJ - 101的土壤中暴露于NiCl2（1750 mg kg(-1)）的植物，其镍积累量为0.147%，相比之下，在未接种土壤中生长的植物干生物量中镍积累量为0.094%。菌株SJ - 101在特定培养基中还表现出产生吲哚乙酸（IAA）（55 μg ml(-1)）和溶解无机磷酸盐（90 μg ml(-1)）的能力。盆栽实验清楚地证明了生物接种剂菌株SJ - 101的有益效果，在未处理的对照土壤中植物生长特性显著增加（p<0.05）。此外，在浓度范围为250 - 1750 mg kg(-1)的NiCl2处理土壤中生长的植物中，菌株SJ - 101对镍植物毒性的保护作用明显。因此，建议由于菌株SJ - 101具有促进植物生长以及通过生物吸附和生物积累降低土壤镍含量的内在能力，可用于从污染场地细菌辅助植物积累这种有毒重金属。
