固碳微生物分子生态学研究

Advances in Research of Molecular Ecology of Carbon Fixation Microorganism

减缓大气"温室效应"是目前最重要且亟待解决的环境问题之一。自养微生物具有极强的环境适应性和不容忽视的固碳潜力,研究微生物固定CO2的分子生态机理对于缓解全球气候变暖具有重要科学意义。目前发现的5条主要生物固碳途径中,卡尔文循环是自养生物固定CO2的主要途径,其中核酮糖-1,5-二磷酸羧化酶/加氧酶(RubisCO)是卡尔文循环中的关键酶,因此RubisCO及其编码基因被许多学者用于不同生态环境中固碳微生物群落结构和多样性的研究。以前的研究主要集中在水生生态系统,揭示了不同水生生态系统中固碳微生物的群落特点及其对不同生境的响应规律。近几年,随着陆地生态系统固碳微生物分子生态学研究的深入,国外学者发现土壤中存在大量的固碳自养微生物,它们在土壤中所起的具体作用和贡献有待进一步研究和验证。至今,国内针对土壤固碳微生物分子生态学的研究还未见报道。论文对固定CO2的微生物种类、固定机理以及近年来关于微生物固定CO2的分子生态学的研究进行了分析和总结,讨论了固碳微生物分子生态学研究存在的主要问题和今后的发展方向,旨在为中国固碳微生物分子生态学研究提供参考。

Alleviating the global climate change is one of the most important environmental challenges human faced. Autotrophic microbes have a strong adaptability to environmental changes and potential to CO2 fixation, thus it is important for researchers to study on molecular mechanisms of CO2 fixation by autotrophic microbes. Most of the autotrophic microbes fix CO2 via Calvin cycle, although there are another four alternative pathways. The crucial reaction of this pathway is catalyzed by the enzyme ribulose-1, 5-bisphos-phatecarboxylase/oxygenase （RubisCO）. Therefore, the RubisCO and the encode gene can be used as functional gene markers to investigate the community and diversity of the CO2 fixation microorganisms in different ecological systems. The previous molecular analysis of microbial carbon fixation has emphasized on aquatic systems, revealing the characteristics of carbon fixation microbial communities and the response to the different habitats. Recent studies on the terrestrial systems have found out that CO2 fixation microorganism also numerous and widespread in soils whereas the functional implication of those autotrophies is not clear, and need to be future identified. Domestic researches on the molecular ecology of soil CO2 fixation microorganism as yet have not been reported. In the present paper, the species of carbon fixation microorganism, the dynamics of CO2 fixation and the current status concerning the carbon fixation by microorganism were reviewed, the main problems and further researches of the molecular ecology of carbon fixation in agricultural ecosystems were also discussed. The aim of this study is to provide useful information for Chinese molecular ecology research of CO2 fixation microorganism.