Characterisation of the microbial community of a ferruginous duricrust in Eastern India and its geomorphic implications

In soils, microorganisms interact with biotic and abiotic components to drive rock-to-soil transformations and imbue soil with its characteristics. We studied the bacterial and fungal communities using total DNA extracted from a soil sample collected from the active weathering zone of a landscape covered by ferruginous duricrust in the Gangani area of Garbeta, Eastern India. The XRF analysis revealed a compositionally matured nature of the ferricrete, whereas poorly sorted grain size indicates a texturally immature character. Molecular characterisation of bacterial and fungal communities through partial sequencing of the 16S and ITS rRNA genes, respectively, revealed a diverse presence of chromium (Cr) and vanadium (V)-tolerant bacterial (Bacillus, Pseudomonas and Serratia) and fungal (Aspergillus, Inocybe, Penicillium, and Pisolithus) genera in the studied sample. Such a microbiome can influence weathering, biomineralisation and nutrient cycling in lateritic/ferricrete landscapes and soils. The presence of Mn-oxidisers (Serratia sp.) and acidophilic iron-oxidisers (Acidithiobacillus sp.), along with Bacillus sp., in combination with mycorrhizal fungi Pisolithus sp., can increase weathering fluxes. The presence of ectomycorrhizal fungi, Inocybe, may have a possible role in stabilising laterite soils. This study is likely the first report of such geomicrobial interactions from eastern India, especially from its lateritic/ferricrete landscapes. Total DNA reveals the presence of bacteria and fungi in ferruginous duricrust. Microbiome can influence biomineralisation and nutrient cycling. XRF analysis reveals compositionally matured but texturally immature ferricrete. Increase weathering flux and stabilise lateritic soil in the active weathering zone.