矿物分解细菌Bacillus sp. L11对钾长石的风化作用

Weathering of potash feldsparby Bacillus sp. L11

摘要:

摘要:【目的】明确从南京钾矿区土壤中分离到的一株矿物分解细菌的分类地位，阐明其对钾长石矿物的风化效应及机制，为深入研究微生物-矿物相互作用提供参考依据。【方法】通过16S rRNA 基因序列分析及其系统发育分析对菌株L11进行鉴定。采用摇瓶试验评估菌株L11对钾长石的风化能力，利用SEM/EDS观察钾长石矿物的形貌变化，使用X-射线衍射技术对小于2μm矿物进行了鉴定。【结果】菌株L11的16S rRNA 基因序列与Bacillusaltitudinis的相似性最高，为99.9%，初步鉴定其为Bacillus sp. L11。摇瓶试验表明，菌株L11能够通过产生有机酸风化钾长石矿物，释放出Si、Al和Fe等元素。通过SEM发现第30 d的钾长石表明形貌发生了较大变化，表面有许多细菌存在，并形成了一些球形物质，EDS分析表明其Fe的含量较高。XRD结果表明，钾长石经菌株L11作用后可能形成了新矿物———菱铁矿。【结论】菌株Bacillus sp. L11能够加速钾长石的风化，改变其形貌，并能诱导新矿物的形成。

Abstract:

Abstract:［Objective］ To determine the taxonomic position of mineral-weathering bacterium L11 isolated from soil of potassium mine tailing of Nanjing and to elucidate the weathering mechanism of the strain，which will offer the basis for the interaction between microorganism and mineral．［Methods］16S rRNA gene was sequenced and neighbor-joining phylogenetic tree was constructed to identify strain L11．The ability of strain L11 to weather potash feldspar was evaluated by shaking culture.Scanning electron microscope and Energy-dispersive spectrometry were used to observe the mineral weathering and to analyze the elements of mineral surface，respectively．Mineral (＜2μm in diameter) was determined by X-ray diffraction.［Results］Phylogenetic analysis of strain L11 based on 16S rRNA gene sequence was closest to Bacillus altitudinis (99.9%) ．Mineral dissolution experiments showed that strain L11 dissolved potash feldspar and significantly released more Si，Al and Fe elements by producing more organic acids．Many bacteria and some spherical minerals were observed on the surfaces of the feldspar and the energy-dispersive spectrometry analysis showed that the new minerals contained more Fe．After 30 days，siderite might be the newly-formed mineral identified by X-ray diffraction in the mineral weathering process．［Conclusion］ Strain Bacillus sp．L11 could accelerate weathering of potash feldspar， changemineral surface morphologyand induce the formation of new mineral complex.