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草业学报 ›› 2021, Vol. 30 ›› Issue (7): 44-52.DOI: 10.11686/cyxb2020265

• 研究论文 • 上一篇    下一篇

产硫化氢细菌的筛选及阻控苜蓿吸收铅和改良土壤的作用

周倩倩(), 张亚见, 张静, 殷涂童, 盛下放, 何琳燕()   

  1. 南京农业大学生命科学学院,农业农村部农业环境微生物重点实验室,江苏 南京 210095
  • 收稿日期:2020-06-08 修回日期:2020-07-06 出版日期:2021-07-20 发布日期:2021-06-03
  • 通讯作者: 何琳燕
  • 作者简介:Corresponding author. E-mail: helyan0794@njau.edu.cn
    周倩倩(1994-),女,安徽淮南人,在读硕士。E-mail: 2964861105@qq.com
  • 基金资助:
    国家自然科学基金项目(41977199);农业农村部产地环境污染防控重点实验室/天津市农业环境与农产品安全重点实验室开放基金项目(16nybcdhj-8);江苏省社会发展项目(BE2016744)

Isolation of a beneficial hydrogen sulfide-producing bacterial strain that reduces lead uptake by Medicago sativa and aids remediation of Pb-contaminated soil

Qian-qian ZHOU(), Ya-jian ZHANG, Jing ZHANG, Tu-tong YIN, Xia-fang SHENG, Lin-yan HE()   

  1. College of Life Sciences,Key Laboratory of Agricultural and Environmental Microbiology,Ministry of Agriculture and Rural Affairs,Nanjing Agricultural University,Nanjing 210095,China
  • Received:2020-06-08 Revised:2020-07-06 Online:2021-07-20 Published:2021-06-03
  • Contact: Lin-yan HE

摘要:

为了探究产硫化氢细菌阻控牧草吸收重金属、修复重金属污染土壤的作用,从生长在矿区污染地的苜蓿中分离纯化产硫化氢细菌,根据菌株生理特性、产硫化氢能力、铅镉抗性以及吸附铅能力筛选高效菌株,然后以某农田受污染土壤为供试土壤,采用田间小区试验,研究高效菌株对紫花苜蓿生长及阻控苜蓿吸收Pb的效果与机制。结果表明,从生长在矿区污染地的苜蓿中分离筛选到一株高产硫化氢细菌Sar15,其具有合成吲哚乙酸(IAA)、铁载体和脲酶的特性,在溶液条件下能显著降低Pb2+的浓度(60%)。经16S rDNA分析将菌株Sar15归属于彭氏变形菌。菌株Sar15能够在紫花苜蓿根部定殖。与不接菌对照相比,菌株Sar15能显著增加受污染农田中生长的苜蓿地上部和根部干重、显著降低其Pb含量。菌株Sar15使得苜蓿地上部和根部Pb含量分别降低43%和45%。并且该菌株能够提高紫花苜蓿根际土壤pH和酶活性,降低根际土壤有效态Pb含量,减轻Pb对紫花苜蓿的毒害。Sar15处理具有修复中度Pb污染土壤、保障牧草安全生产的潜力。

关键词: 紫花苜蓿, Pb污染, 产硫化氢细菌

Abstract:

This research explored the roles of hydrogen sulfide-producing bacteria in preventing forages from absorbing heavy metals and in remediation of soil contaminated by heavy metals. From alfalfa growing at a locality contaminated by nearby mining activities, a bacterial strain, Sar15, with high hydrogen sulfide production was isolated. Sar15 was found to synthesize indole-3-acetic acid (IAA), siderophores and urease, and to reduce the concentration of Pb2+ in solution by 60% (P<0.05). Using 16S rDNA analysis the strain Sar15 was identified as Proteus penneri. A field experiment was then conducted to evaluate the potential influence of this hydrogen sulfide-producing bacterial strain on the growth ofalfalfaand its role in the inhibition of Pb uptake by alfalfa in Pb-contaminated farmland. It was found that P. penneri strain Sar15 was the most efficient in producing hydrogen sulfide and could colonize on the roots of alfalfa. Compared with the control, the strain Sar15 increased the dry weight of alfalfa and significantly reduced its Pb content by 44%-45% (P<0.001). P. penneri strain Sar15 also increased the rhizosphere soil pH and enzyme activity, reduced the available Pb content in the rhizosphere soil, and reduced the toxicity of Pb to alfalfa. Inoculationof P. penneri strain Sar15 has the potential to mitigate moderately Pb-contaminated soil and ensure safe forage production.

Key words: Medicago sativa, Pb pollution, hydrogen sulfide-producing bacteria