Role of iron in azoreduction by resting cells of Shewanella decolorationis S12

Abstract

Aim: To investigate the role of soluble and insoluble iron in azoreduction by resting cells of Shewanella decolorationis S12. Methods and Results: A series of analytical experiments were carried out. Results showed that insoluble Fe2O3 all delayed the reduction of amaranth but did not inhibit it. Adsorption to Fe2O3 particles by the bacterial cell surface could be the reason leading to the delay in azoreduction. For the soluble iron, an important finding was that azoreduction activities were inhibited by soluble iron in high concentration because of its higher redox potential, and the inhibition was strengthened when the electron donor supply was insufficient. However, activities of azoreduction could be enhanced by low concentration of soluble iron. This stimulating effect was because of the electron transfer but not the cell growth. Conclusions: The effects of iron on azoreduction by the resting cells depended on the solubility and concentration of the iron compounds, which was different from what was observed by the growing cells in the previous studies. Significance and Impact of the Study: This study has both theoretical significance in the microbial physiology and practical significance in the bioremediation of azo dyes‐contaminated environment.

Evaluation of simultaneous reduction of Fe(II)EDTA‐NO and Fe(III)EDTA by a bacterial pure culture

“…The lack of effects of rotenone on Fe(III)EDTA and Fe(II)EDTA‐NO reduction basically agrees with the data in earlier reports . As for NaN 3 , the tolerance of Fe(III)EDTA reduction was also recognized by other research while the effect on Fe(II)EDTA‐NO reduction was inconsistent with Matsubara and Iwasaki's result that NaN 3 decreased the rate of nitrous oxide formation . The doses used and the nature of NO might be contributed to the discrepancies.…”

Anaerobic biodecolorization of AO7 by a newly isolated Fe(III)-reducing bacteriumSphingomonasstrain DJ

“…Hence, the results indicated that Fe(III) as an energy source could enrich the biomass, promoting decolorization. On the other hand, the electron transfer cycle in the Fe (III)–dye reaction mixture might be attributed to a redox mediator containing iron and binding protein with lower redox potential than that of azo dyes …”

Isolation and Characterization of a Molybdenum-reducing and Carbamate-degrading Serratia sp. strain Amr-4 in soils from Egypt

“…Methods to speed up characterisation and collect more data were employed in this study using a simple, high-throughput method employing microplates [38,42]. Resting cells have been utilized in exploring the biological reduction of heavy metals including vanadate [43], selenate [44], chromate [45], reductions and xenobiotics biodegradation such as dyes [46,47], diesel [48], SDS [49], phenol [50], amides [51] and pentachlorophenol [52].…”