Environmental Science and Pollution Research

, Volume 25, Issue 20, pp 19975–19988 | Cite as

Poly-γ-glutamic acid, a bio-chelator, alleviates the toxicity of Cd and Pb in the soil and promotes the establishment of healthy Cucumis sativus L. seedling

  • Xiao Pang
  • Peng Lei
  • Xiaohai Feng
  • Zongqi XuEmail author
  • Hong XuEmail author
  • Kun Liu
Research Article


Poly-γ-glutamic acid (γ-PGA) can be used as a chemical stabilizer to chelate heavy metals in polluted soils. We investigated the effects of γ-PGA on cucumber seedlings under Cd and Pb stresses. γ-PGA effectively reduced the growth inhibitory effects of Cd and Pb on cucumber seedlings. Cd and Pb absorption in cucumber seedlings was also decreased. Further, γ-PGA decreased the malondialdehyde content, and increased the proline content and the total antioxidant capacity of cucumber seedlings in a dose-dependent manner. Infrared spectral characterization of γ-PGA-Cd and γ-PGA-Pb showed that Cd2+ and Pb2+ bind to free carboxyl groups on γ-PGA. Furthermore, γ-PGA-Cd and γ-PGA-Pb were degraded by 22.02 and 24.68%, respectively, within 28 weeks. The chelating rate of γ-PGA-Pb and γ-PGA-Cd reached 27.26 and 14.28%, respectively. Further, γ-PGA alleviated the negative effects of Cd and Pb on soil microorganisms. Thus, γ-PGA can effectively reduce the accumulation of heavy metals in crops caused by heavy metal pollution of farmland, and has significant application value.


Poly-γ-glutamic acid Bio-chelator Pb pollution Cd pollution Cucumis sativus L. Soil microorganisms 


Funding information

This work was funded by The Key Projects in the National Science & Technology Pillar Program during the Twelfth Five-year Plan Period (No. 2015BAD15B04), the National Nature Science Foundation of China (21506098), and the Natural Science Foundation of the Jiangsu (BK20150946).


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Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2018

Authors and Affiliations

  1. 1.Jiangsu National Synergetic Innovation Center for Advanced MaterialsNanjing Tech UniversityNanjingPeople’s Republic of China
  2. 2.Nanjing Institute for Comprehensive Utilization of Wild PlantsNanjingPeople’s Republic of China

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