Effects of bamboo-charcoal modified by bimetallic Fe/Pd nanoparticles on n-hexane biodegradation by bacteria Pseudomonas mendocina NX-1

Abstract

The high hydrophobicity of n-hexane is the main reason why it is difficult to be removed biologically. In this study, the effects of bamboo-charcoal modified by bimetallic Fe/Pd (BBC) on n-hexane biodegradation by Pseudomonas mendocina NX-1 (PM) was investigated. The n-hexane removal efficiency was increased in the presence of BC. The highest n-hexane removal efficiency at 90.0% was achieved at 0.05 g L^-1 BCE and 3 g L^-1 NH₄⁺ under pH 7.7 and 35 °C. Additionally, protein content (45.9 μg mL^-1) and negative cell surface zeta potential (-26.4 mV) were increased during biodegradation process, with PM-BBC being 43.1 μg mL^-1 and 19.1 mV. Bacterial growth was improved and maximum cell surface hydrophobicity was obtained after 20 h, which was 59.4% higher than the control with PM-BBC (37.7%) or PM (16.1%), showing biodegradation products of 1-butanol and acetic acid. The results indicate that BBC improved n-hexane biodegradation efficiency by promoting bacterial growth, reducing cell zeta potential, exposing hydrophobic proteins, and increasing cell surface hydrophobicity of bacterial strain NX-1. This investigation suggests that BBC-enhanced biodegradation can be promising to treat n-hexane-containing gas.

Keywords: Biodegradation; Biodegradation products; Cell surface hydrophobicity; Fe/Pd bimetallic nanoparticles; Removal efficiency.