Estimating the growth rate of slowly growing marine bacteria from RNA content.

摘要: In past studies of enteric bacteria such as Escherichia coli, various measures cellular RNA content have been shown to be strongly correlated with growth rate. We examined this correlation for four marine bacterial isolates. Isolates were grown in chemostats at or five dilution rates, yielding rates that spanned the range typically determined communities nature (μ = 0.01 0.25 h-1). All (RNA cell-1, RNA:biovolume ratio, RNA:DNA RNA:DNA:biovolume ratio) significantly different among Normalizing cell volume substantially reduced, but did not eliminate, these differences. On average, between μ and ratio accounted 94% variance when isolates considered individually. For data pooled across (analogous an average measurement a community), μm-3 (cell volume) nearly half (r2 0.47). The maximum each isolate was extrapolated from regressions. regression (RNA:DNA)/(RNA:DNA)max on highly significant 0.76 isolates) virtually identical three isolates, perhaps reflecting underlying common relationship dissimilar only one derived sediment. Cellular is likely useful predictor rate slowly growing practice may most successful applied level individual species.