TY - JOUR

T1 - Effect of Trophic Status on the Culturability and Activity of Bacteria from a Range of Lakes in the English Lake District

AU - Porter, Jonathan

AU - Morris, Samantha A.

AU - Pickup, Roger W.

PY - 2004/4/1

Y1 - 2004/4/1

N2 - The bacterioplankton from a number of lakes that differed in nutrient status in the English Lake District was examined with a number of techniques for enumeration and activity assessment. Natural water samples showed a clear correlation between total counts and trophic status. Esterase activity measurements with Chemchrome B were able to distinguish high- and low-nutrient-status lakes, whereas tetrazolium salt (5-cyano-2,3-ditoyltetrazolium chloride) reduction, the direct viable count-cell elongation assay, and culturability measurements could not. Tetrazolium salt reduction and esterase activity measurements labeled a significant number of cells from water of all nutrient levels, whereas the direct viable count-cell elongation method was of use only in oligotrophic waters. Size fractionation of samples showed that the culturable cells were retained by the larger filters, especially in nutrient-rich waters. Esterase activity measurements also favored the larger cells. The differences observed between assays using water that differed in trophic status raise questions about the use of these tests as a definitive measure of viability.

AB - The bacterioplankton from a number of lakes that differed in nutrient status in the English Lake District was examined with a number of techniques for enumeration and activity assessment. Natural water samples showed a clear correlation between total counts and trophic status. Esterase activity measurements with Chemchrome B were able to distinguish high- and low-nutrient-status lakes, whereas tetrazolium salt (5-cyano-2,3-ditoyltetrazolium chloride) reduction, the direct viable count-cell elongation assay, and culturability measurements could not. Tetrazolium salt reduction and esterase activity measurements labeled a significant number of cells from water of all nutrient levels, whereas the direct viable count-cell elongation method was of use only in oligotrophic waters. Size fractionation of samples showed that the culturable cells were retained by the larger filters, especially in nutrient-rich waters. Esterase activity measurements also favored the larger cells. The differences observed between assays using water that differed in trophic status raise questions about the use of these tests as a definitive measure of viability.

U2 - 10.1128/AEM.70.4.2072-2078.2004

DO - 10.1128/AEM.70.4.2072-2078.2004

M3 - Journal article

C2 - 15066798

AN - SCOPUS:16544383866

VL - 70

SP - 2072

EP - 2078

JO - Applied and Environmental Microbiology

JF - Applied and Environmental Microbiology

SN - 0099-2240

IS - 4

ER -