Microbially Induced Redistribution of Chromium Geochemical Fractions in Distinct Soil and Sediment Types

While microbial reduction of Cr(VI) has been widely reported, the information regarding microbial effects on the Cr geochemical fractions and their mobility across the soil-sediment system is limited. This study investigates the capacity of an indigenous Cr(VI)-reducing bacterium, <i>Bacillus cereus</i> jv10, to drive Cr geochemical fraction redistribution and mobility attenuation in three distinct environmental matrices: municipal solid waste dumpsite soil, agrarian wetland soil, and estuarine lagoon sediments.

The isolate demonstrated 95% reduction of 100 mg/L Cr(VI) within 72 h. FTIR and XPS analysis revealed the involvement of cell-surface functional groups (hydroxyl, carboxyl, amine, phosphate) consistent with extracellular Cr(VI) biotransformation to Cr(III). Cellular fractionation showed 90% of Cr products localized within the supernatant and cell-associated components.