Medycyna Wet. 67 (2), 105-109, 2011
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| Olszewska M., Łaniewska-Trokenheim Ł. |
| Study of the nonculturable state (viable but non-culturable – VBNC) of lactic acid bacteria cells under various adverse growth conditions |
| The reason for undertaking the research concerning the physiological state of lactic acid bacteria is closely associated with applications of these microorganisms in the food industry. An increased demand referring to microbiological analysis has been affected by the intensification of research assessing the physiological state of microorganisms in unfavorable for them conditions. In technological processes as well as in natural habitats microorganisms can encounter a variety of adverse conditions, arising from the influence of physical and chemical factors such as extremes in temperature, pH or presence of bacteriostatic agents. Therefore, the determination of the viability of bacteria may be challenging due to difficulties in the selection of suitable enumeration methods. The use of conventional methods that rely on the replication and colony formation on growth media is hindered by the decreased reproductive capacity of cells under detrimental conditions. As a result, alternative techniques which do not focus on cell proliferation, but on the metabolic activity or cell structure integrity are being favored. Approaches performing direct detection of different physiological parameters of microbes are connected with the application of modern fluorescence techniques, and in consequence with progress in microbiological research. |
| Keywords: lactic acid bacteria, physiological state, fluorescence techniques |