US EPA

8214482 

Journal Article 

The kinetic characteristics of the microbial dissimilatory reduction of lepidocrocite 

Zhu, W; Yao, T; Huang, T 

2012 

Yes 

Huanjing Kexue Xuebao / Acta Scientiae Circumstantiae
ISSN: 0253-2468 

32 

6 

1348-1356 

Chinese 

Dissimilatory Fe(III) and Mn(IV) oxide reduction by microorganisms has an important influence on the geochemistry and fate of organic or metal contaminants in the environment. Identification of the kinetic characteristics of the microbial reduction of Fe(III) and Mn(IV) oxide is the key to understand the mechanism of the interaction of "microbial-oxide-contaminants". The current study mainly discussed the influence of anthraquinone-2-sulfonate (AQS), the concentration of the electron donor and lepidocrocite on the reduction of lepidocrocite by S12.The results showed that the electron shuttle, AQS, can enhance the degree of lepidocrocite reduction. In the system containing 20 mmol·L -1 lactate and 10 mmol·L -1 lepidocrocite, the reductively produced Fe(II) concentration was as much as 1.80 times that in the non-AQS addition cell-lepidocrocite reaction system. The Michaelis-Menten kinetic model fit calculations showed significant correlation between the initial reduction rate and the substrate concentration with a correlation coefficient, Adj. R-Square, R 2, as high as 0.9348.The electron shuttle, AQS, had considerable influence on V max and K m values and enhanced the degree of the bioreduction of lepidocrocite, leading to more energy (ΔE) driving ATP synthesis. When the microbial redox reaction almost kept in balance, the ΔG r values reached the maximum. 

Kinetic characteristics; Lepidocrocite; Microbial dissimilatory reduction