Enhanced phosphate uptake and polyphosphate accumulation in "Burkholderia cepacia" grown under low-pH conditions
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[1] School of Biology and Biochemistry and QUESTOR Centre, The Queen’s University of Belfast, Northern Ireland View author publications
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- Localización: Microbial ecology, ISSN-e 1432-184X, ISSN 0095-3628, Vol. 44, Nº. 1, 2002, págs. 69-77
- Idioma: inglés
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Resumen
Of bacterial cells in a sample of activated sludge, 34% contained detectable intracellular polyphosphate inclusions following Neisser staining when grown on glucose/mineral salts medium at pH 5.5; at pH 7.5 only 7% of cells visibly accumulated polyphosphate. In a sludge isolate of Burkholderia cepacia chosen for further study, maximal removal of phosphate and accumulation of polyphosphate occurred at pH 5.5; levels were up to 220% and 330% higher, respectively, than in cells grown at pH 7.5. During the early stationary phase of growth at pH 5.5 a maximum level of intracellular polyphosphate that comprised 13.6% of cellular dry weight was reached. Polyphosphate kinase activity was detected in actively growing cells only when cultured at pH 5.5. The phenomenon of acid-stimulated phosphate uptake and polyphosphate accumulation in this environmental bacterial population parallels observations previously made by us in the yeast Candida humicola and may thus represent a widespread microbial response to low external pH values.
