Abstract

The bio-weathering process contributes majorly in the physical shaping of earth’s surface. The weathering of mineral is coupled to the formation of new minerals and release of bio-available nutrients for flora as well as microbial communities. Granites from the Eastern Dharwar Craton (EDC) India are felsic plutonic igneous rock composed of nutritive minerals. The major elemental composition of granite is such that, it forms an ancient ecological niche for diverse microbial communities. Interdisciplinary approaches were taken to construct a more comprehensive understanding of potential functional attributes of Actinobacteria in bio-weathering of granite. This work includes molecular characterization of the isolated strains, detecting their granite bioweathering potentials through leaching experiments where Nocardioides showed highest mineral leaching indices with iron (Fe) being the most leached element (~ 6372 ppm). Scanning electron microscopic imaging indicated biofilm formation and Actinobacterial hyphae colonization. Petrographic, XRD and FTIR based study shows formation of secondary minerals (kaolinite, vermiculite and smectite). To further establish the hypothesis of soil formation and nutrition transport, long-term (360 days) microcosm was developed. Deterioration and grain size alternations with increase in clay based minerals (kaolinite, vermiculite) and total protein content was observed. A bioinformatics based functional biodiversity approach in link to global bio-weathering of rocks by the genus Actinobacteria was adopted to understand their distribution patterns and contribution to alterations of rock minerals.

Graphic abstract

中文翻译：

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东部Dharwar Craton（印度）的花岗岩的生物风化：细菌代谢和矿物化学的探戈

摘要

生物风化过程主要有助于地球表面的物理塑形。矿物质的风化与新矿物质的形成以及植物群和微生物群落的生物可利用营养释放有关。来自印度东部Dharwar Craton（EDC）的花岗岩是由营养矿物质组成的长英质岩浆火成岩。花岗岩的主要元素组成是，它构成了各种微生物群落的古老生态位。采取了跨学科的方法来构建对放线菌在花岗岩生物风化中潜在功能属性的更全面的了解。这项工作包括对分离菌株的分子鉴定，通过浸出实验检测其花岗岩的生物风化潜力，其中诺卡氏菌显示出最高的矿物浸出指数，其中铁（Fe）是浸出率最高的元素（〜6372 ppm）。扫描电子显微镜成像表明生物膜形成和放线菌丝菌落定植。基于岩石学，XRD和FTIR的研究表明形成了次生矿物（高岭石，ver石和蒙脱石）。为了进一步确立土壤形成和营养运输的假设，开发了长期（360天）的缩影。观察到随着粘土基矿物质（高岭石，ver石）和总蛋白质含量的增加而恶化和晶粒尺寸变化。基于生物信息学的功能性生物多样性方法，与放线菌属的岩石在全球的生物风化相关 旨在了解它们的分布模式以及对岩石矿物蚀变的贡献。

图形摘要