The abiotic oxidation of petroleum hydrocarbons using reduced iron-bearing clay minerals affect the microbial degradation function.

Here we undertook a comprehensive study that involved both abiotic oxidation (by OH) and subsequent biological oxidation (by thermophiles in Tengchong hot spring) of petroleum hydrocarbons (contains a wide variety of hydrocarbons). These processes were facilitated by the oxidation and reduction of an iron-rich smectite, nontronite (NAu-2), respectively. Our objective was to assess the influence of altered petroleum hydrocarbons on their biodegradation mechanisms upon Fe cycling. We analyzed the Fe(II) concentration, hydrocarbons, oxygen-containing compounds, mineral transformation, bacterial community, and functional genes. These analyses were supported by wet-chemical method, mineralogy, organic geochemistry, molecular biology and metagenomics.