2株可培养细菌氮代谢特性的研究

Nitrogen Metabolic Characteristics of Two Cultivable Bacteria

研究旨在分析土壤中可培养细菌菌株的氮代谢特征,并进一步探讨微生物在土壤氮素转化中的可能作用机制。以2株分离自苹果园土壤的细菌菌株SY5-4和SY11-10为试材,采用传统培养方法结合分子检测技术,分别测定菌株生长特性及其氮素转化能力。研究结果表明,异养条件下,菌株SY5-4和SY11-10的世代时间分别为243.5 min和202.7 min。菌株生长过程中,培养液中铵态氮浓度始终维持在较高水平,铵态氮、亚硝态氮和硝态氮浓度均表现出先升后降的趋势。硝化(amo A和hao)和反硝化(nos Z、nor B、nir K和nap)基因检测结果表明,菌株SY11-10具有多种氮素转化潜能。综上,供试菌株培养过程中,培养液中氮素发生变化,并在菌体中检测到不同氮转化基因,表明菌株参与多种氮代谢途径。

To study the N metabolic characteristics of culturable bacteria in soil,and discuss the possible mechanism of microorganisms in soil N transformation,2 strains,named SY5-4 and SY11-10 isolated from apple orchard soil were selected to analyze the growth characteristics,and their capabilities of nitrogen transformation,by using the traditional culture method combined with molecular technology.The results showed that,in heterotrophic condition,the generation time of SY5-4 and SY11-10 was 243.5 min and 202.7 min,respectively.The concentration of NH4+-N in the medium maintained at a high level,while the concentration of NH4+-N,NO2--N and NO3--N increased first and decreased afterwards,in the process of bacterial growth.The nitrification(amoA and hao),and denitrification(nosZ,norB,nirK and nap) gene detection showed that,strain SY11-10 had a variety of N transformation potential.In conclusion,the nitrogen in medium changed in the process of bacterial growth,and different nitrogen transformation genes were detected in the tested strains,which indicated that the isolated strains participated in various N metabolism pathways.