TABLE 1.

Growth rates of mixed communities and pools of isolated bacteria from systems exposed to nutrient pulses at 1-, 3-, 7-, or 14-day intervalsa

Pulse interval (days)Growth rateb (h−1, mean ± SE) of community (n = 3)ncGrowth rated (h−1, mean ± SE) at day after incubation:
13714
10.48 ± 0.019 (6)0.47 ± 0.030.43 ± 0.030.32 ± 0.020.33 ± 0.03
30.35 ± 0.048 (8)0.41 ± 0.030.37 ± 0.030.29 ± 0.020.32 ± 0.03
70.29 ± 0.0210 (5)0.48 ± 0.030.45 ± 0.040.37 ± 0.040.34 ± 0.05
140.15 ± 0.025 (3)0.27 ± 0.090.29 ± 0.070.27 ± 0.070.20 ± 0.04
  • a Bacteria were isolated after systems were operated for 90 days.

  • b The community growth rates that are reported were those measured after 90 days of operation.

  • c n, number of isolates. The number of isolates in which the mobility of PCR amplicons matched a band in the corresponding mixed community is given in parentheses.

  • d Average growth rates for all isolates obtained from a pulse interval, when tested after different intervals since nutrient addition. The values in boldface correspond to the incubation period that corresponds to the pulse interval from which the bacteria were isolated.