不同风化程度钾长石表面矿物分解细菌的筛选及遗传多样性

Isolation and genetic diversity of mineral-solubilizing bacteria of different weathered potassium-feldspars

摘要:

摘要：【目的】不同风化程度钾长石表面矿物分解细菌生物多样性研究将有助于了解矿物生物风化、生物成矿和土壤形成的演化规律和机理。【方法】采用纯培养法自南平钾矿区高、中、低风化度钾长石以及矿区土壤样品中分离矿物分解细菌，通过摇瓶释硅实验比较不同菌株分解矿物能力，采用16S rDNA限制性酶切多态性分析（Amplified rDNA Restriction Analysis，ARDRA）研究了供试菌株的遗传多样性。【结果】分离筛选到35株生长良好的矿物分解细菌，与对照相比，接菌处理发酵液中有效硅增加了101~206％；所有供试菌株可分为11个OTU，分别属于5个门，6个科，7个属。多数菌株（74％）属于γ-变形杆菌纲（γ-Proteobacteria）。泛菌属（Pantoea），沙雷氏菌属（Serratia），假单胞菌属（Pseudomonas）为优势种群。【结论】南平钾矿区矿物分解细菌具有丰富的微生物种群多样性，且γ-变形杆菌纲（γ-Proteobacteria）细菌在钾长石风化过程中可能起了重要的作用。

Abstract:

Abstract: [Objective] We isolated and characterized potassium-bearing mineral-solubilizing bacteria from the surfaces of weathered feldspar as well as soil samples. [Methods] We isolated cultivable mineral-solubilizing bacteria by plating and screening from the surfaces of different level of weathered feldspar as well as soil samples. We characterized bacteria regarding their ability of releasing Si from feldspar samples and further classified by amplified rDNA restriction analyses (ARDRA). Twelve typical bacterial strains were identified by 16S rDNA sequence analysis. [Results] Thirty-five Si-releasing bacteria were isolated from the surfaces of weathered feldspar and soil samples and classified by ARDRA in 11 different operational taxonomic units (OTU) at the similarity level of 60%, belonging to 5 major phylogenetic groups, 6 families, and 7 genera (Pantoea, Pseudomonas, Serratia, Agrobacterium, Sphingobacterium, Exiguobacterium, and Microbacterium). Pantoea, Pseudomonas and Serratia were the dominant groups. Inoculation with the isolates was found to increase the Si in the solution by 101~206% compared to the control. [Conclusions] Different mineral- solubilizing bacteria inhabited in different weathered K-feldspar surfaces and soils in the potassium mine. γ-Proteobacteria might play an important role in the process of K-feldspar weathering.