Association with an Ammonium-Excreting Bacterium Allows Diazotrophic Culture of Oil-Rich Eukaryotic Microalgae
Association with an Ammonium-Excreting Bacterium Allows Diazotrophic Culture of Oil-Rich Eukaryotic Microalgae
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DOI：
10.1128/aem.06260-11
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发表时间：
2012-04-01
影响因子：
4.4
通讯作者：
Curatti, Leonardo
中科院分区：
文献类型：
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作者：
Federico Ortiz-Marquez, Juan Cesar;Do Nascimento, Mauro;Curatti, Leonardo
对世界石油储备枯竭和全球气候变化的关切促使在过去几年中加紧研究和开发生物燃料和其他替代能源的生产。目前，人们对开发利用微藻生物质生产第三代生物燃料的技术很感兴趣，主要是因为与利用植物原料生产的生物燃料相比，微藻生物质具有高产和减少土地使用变化的潜力。无论原料的性质如何，使用肥料，特别是氮，都会对生物燃料生产的可持续性造成潜在的经济和环境缺陷。在这项工作中，我们已经研究了氮生物施肥的可能性固氮菌应用于培养的微藻作为下一代生物燃料的一个有前途的原料。我们已经获得了棕色固氮菌突变株，其在培养基中积累的铵比野生型细胞多几倍。突变体细胞分泌的铵具有生物可利用性，可促进非重氮营养型微藻的生长。此外，这种合成共生能够利用空气中的碳和氮产生富含石油的微藻生物质。这项工作提供了一个概念证明，人工共生可能被认为是一种替代战略的低氮密集型微藻的可持续生产下一代生物燃料和其他生物产品。
Concerns regarding the depletion of the world's reserves of oil and global climate change have promoted an intensification of research and development toward the production of biofuels and other alternative sources of energy during the last years. There is currently much interest in developing the technology for third-generation biofuels from microalgal biomass mainly because of its potential for high yields and reduced land use changes in comparison with biofuels derived from plant feedstocks. Regardless of the nature of the feedstock, the use of fertilizers, especially nitrogen, entails a potential economic and environmental drawback for the sustainability of biofuel production. In this work, we have studied the possibility of nitrogen biofertilization by diazotrophic bacteria applied to cultured microalgae as a promising feedstock for next-generation biofuels. We have obtained an Azotobacter vinelandii mutant strain that accumulates several times more ammonium in culture medium than wild-type cells. The ammonium excreted by the mutant cells is bioavailable to promote the growth of nondiazotrophic microalgae. Moreover, this synthetic symbiosis was able to produce an oil-rich microalgal biomass using both carbon and nitrogen from the air. This work provides a proof of concept that artificial symbiosis may be considered an alternative strategy for the low-N-intensive cultivation of microalgae for the sustainable production of next-generation biofuels and other bioproducts.