Open AccessAlkaline Fe ( III ) reduction by a novel alkali‐tolerant S erratia sp. isolated from surface sediments close to S ellafield nuclear facility, UK
Author(s) -
Thorpe Clare L.,
Morris Katherine,
Boothman Christopher,
Lloyd Jonathan R.
Publication year - 2012
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.2011.02455.x
Subject(s) - denitrification , electron acceptor , chemistry , nitrate , environmental chemistry , nuclear chemistry , inorganic chemistry , biochemistry , organic chemistry , nitrogen
Extensive denitrification resulted in a dramatic increase in pH (from 6.8 to 9.5) in nitrate‐impacted, acetate‐amended sediment microcosms containing sediment representative of the S ellafield nuclear facility, UK . Denitrification was followed by Fe ( III ) reduction, indicating the presence of alkali‐tolerant, metal‐reducing bacteria. A close relative (99% 16 S rRNA gene sequence homology) to S erratia liquefaciens dominated progressive enrichment cultures containing Fe ( III )‐citrate as the sole electron acceptor at pH 9 and was isolated aerobically using solid media. The optimum growth conditions for this facultatively anaerobic S erratia species were investigated, and it was capable of metabolizing a wide range of electron acceptors including oxygen, nitrate, FeGel , Fe ‐ NTA and Fe ‐citrate and electron donors including acetate, lactate, formate, ethanol, glucose, glycerol and yeast extract at an optimum pH of c . 6.5 at 20 ° C . The alkali tolerance of this strain extends the pH range of highly adaptable Fe ( III )‐reducing S erratia species from mildly acidic pH values associated with acid mine drainage conditions to alkali conditions representative of subsurface sediments stimulated for extensive denitrification and metal reduction.