TABLE 3.

Summary of the regression parameters for estimating the growth (slope) and grazing mortality rate (y intercept) of the bulk bacterial community (total) and bacteria belonging to three different phylogenetic groups (α- and γ-proteobacteria and the Cytophaga-Flavobacter cluster [CF])a

ExptGroupr2PGrazing rate, day−1 (avg ± SE)Growth rate, day−1 (avg ± SE)
1Alpha0.47<0.051.97 ± 0.850.65 ± 0.55
Gamma0.80<0.011.59 ± 0.210.63 ± 0.33
CF0.49<0.051.77 ± 0.741.28 ± 0.46
Total0.89<0.011.59 ± 0.230.93 ± 0.15
2Alpha0.74<0.014.41 ± 1.072.71 ± 0.69
Gamma0.81<0.013.24 ± 0.652.84 ± 0.42
CF0.89<0.013.03 ± 0.441.90 ± 0.29
Total0.98<0.012.92 ± 0.142.23 ± 0.09
  • a Duplicate bottles were used for each dilution series (n = 8). ANCOVA results to test the differences in slope and y intercept among different bacterial groups are as follows. For slope, df = 2, 18 (degree of freedom, residual degree of freedom), F=0.082, and P = 0.921 for experiment 1, and df = 2, 18, F = 0.944, and P = 0.407 for experiment 2. For y intercept, df = 2, 20, F = 4.313, and P < 0.05 for experiment 1, and df = 2, 20, F = 4.543, and P < 0.05 for experiment 2.