福州森林红壤细菌的菌群结构及其功能分析

Community Construction and Function of Soil Bacteria in A Forest Decomposed-hollow Stump Environment

福建地区是我国的第二大林区,土壤类型主要表现为红壤。对福州地区森林中因木材腐朽而形成的树洞中的土壤样品进行筛选,构建了一份具有强木质纤维素降解能力的酸性红壤的细菌16S rRNA基因文库,利用限制性片段长度多态性(RFLP)对随机克隆进行筛选;对该生态环境下的细菌菌群进行了系统发育分析。结果表明土壤pH偏酸性严重影响了细菌类群的多样性,酸杆菌门Acidobacteria(71.5%)和变形菌门Proteobacteria(24.1%)是该酸性土样中的优势菌群,其中酸杆菌门在该生态系统中占有绝对优势。变形菌菌群中的主要类群为光合细菌,固氮细菌和溶菌细菌。研究表明,在木质纤维素自然降解的过程中,存在于酸性树洞土壤中的细菌参与了碳素和氮素的固定与循环,并对其微生态的稳定起到重要作用。

In this study,bacterial community of an acid soil in hollow stump ecosystem from native forest at Fuzhou was characterized by constructing and analyzing rRNA gene clone library. The clone library was screened by restriction fragment length polymorphism（RFLP）,and representative rRNA gene sequences were determined. Phylogenetic sequence analyses revealed the soil pH have a significant effects on diversity of putative bacterial community. Members of these bacteria mainly included Acidobacteria （71.5%） and Proteobacteria （24.1%）. Most proteobacterial clones belong to members of Rhizobium,photosynthetic and bacteriolytic bacteria. This study indicated bacterial community of this acid soil ecosystem played an important role in C,N cycles and maintaining integrity of the ecosystem.