Iron reduction characteristics and kinetic analysis of Comamonas testosteroni Y1: a potential iron-reduction bacteria

Microbial-mediated anaerobic iron reduction has become a frequently discussed topic in the environmental pollution control and remediation field, and iron reduction bacteria involved in this process have also attracted much social and scientific attention. In order to isolate iron-reducing bacteria and explore its iron-reducing characteristics, an anaerobic iron-reducing bacteria, isolated from activated sludge, was identified as Comamonas testosteroni Y1. The effects of carbon source, iron source and pH on ferric reduction and bacterial growth were separately studied in this work. Three-dimensional fluorescence spectroscopy analysis demonstrated that glucose and sucrose acted as electron donors could be effectively utilized by Comamonas testosteroni Y1 during the iron reduction process. In addition, the cell growth kinetics and its relationship with Fe(Ⅲ) formation were both investigated. Cell growth data well fitted with the logistics model. Luedeking-Piret model has been proved to effectively describe the relationship between cell growth and ferrous iron production. The model parameters α and β implied that the formation of Fe2+ during anaerobic iron respiration was partly related to cell growth. In summary, the discovery of iron reduction ability of Comamonas testosteroni Y1 will provide some new potential methods for the research on microbial synergistic degradation of organic pollutants with ferric iron.