ISSN:
1432-072X
Keywords:
Metallogenium
;
Manganese-oxidizing bacteria
;
pH dependence
;
Bicarbonate
;
Electron acceptor
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract As a model of chemically stratified structure of environment typical to the chemocline of lakes, a semisolid gradient medium was prepared to cultivate heterotrophic manganese-oxidizing bacteria originally collected from a lake. The bacteria growing under the conditions described produced extracellularly Metallogenium-like particles similar to those which are often detected in the chemocline of lakes. This suggested that the naturally occurring Metallogenium-like particles originated in activities of such heterotrophic manganese-oxidizing bacteria. The manganese oxidation activity usually appeared only at the stationary phase of bacterial growth. The oxidation of Mn2+ and the formation of Metallogenium-like particles by the bacteria were observed at neutral or slightly acidic pH. not under alkaline conditions, which is a conspicuous difference from the inorganic oxidation of Mn2+ by O2. Bacterial manganese oxidation was stimulated by bicarbonate (50 or 500 μM). An experiment of addition of H2O2 to the incubation tubes isolated from atmosphere failed to confirm the availability of externally added H2O2 as the electron acceptor, suggesting that the bacterial manganese oxidation required the presence of O2.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00245212
Permalink
