Improved Eco-Friendly Recombinant Anabaena sp. Strain PCC7120 with Enhanced Nitrogen Biofertilizer Potential
Improved Eco-Friendly Recombinant Anabaena sp. Strain PCC7120 with Enhanced Nitrogen Biofertilizer Potential
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DOI：
10.1128/aem.01714-10
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发表时间：
2011-01-01
影响因子：
4.4
通讯作者：
Apte, Shree Kumar
中科院分区：
文献类型：
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作者：
Chaurasia, Akhilesh Kumar;Apte, Shree Kumar
光合、固氮的水藻菌株原产于热带稻田，并有助于这些土壤的碳和氮经济。采用基因工程的方法，提高了Anabaena sp.菌株PCC7120的氮肥潜能。在重组菌株中，通过光诱导启动子构建增强表达hetR基因的额外整合拷贝可提高hetR蛋白的表达并增强功能性异囊频率。重组菌株的氮酶活性始终高于野生型菌株，并且在光合作用和呼吸作用的协调调节下处于稳态状态。重组菌株提高了组合氮素有效性，积极迎合了短期水培试验中水稻幼苗对氮的需求，支持了水稻幼苗更好的生长。该工程菌株稳定、生态友好，可作为水田氮素生物肥料环境利用。
Photosynthetic, nitrogen-fixing Anabaena strains are native to tropical paddy fields and contribute to the carbon and nitrogen economy of such soils. Genetic engineering was employed to improve the nitrogen biofertilizer potential of Anabaena sp. strain PCC7120. Constitutive enhanced expression of an additional integrated copy of the hetR gene from a light-inducible promoter elevated HetR protein expression and enhanced functional heterocyst frequency in the recombinant strain. The recombinant strain displayed consistently higher nitrogenase activity than the wild-type strain and appeared to be in homeostasis with compatible modulation of photosynthesis and respiration. The enhanced combined nitrogen availability from the recombinant strain positively catered to the nitrogen demand of rice seedlings in short-term hydroponic experiments and supported better growth. The engineered strain is stable, eco-friendly, and useful for environmental application as nitrogen biofertilizer in paddy fields.