TABLE 1.
Characteristic | Control microcosms
|
Enriched microcosms
|
||
---|---|---|---|---|
C1 | C2 | NUT1 | NUT2 | |
BBP (μM C) | 0.24 | 0.30 | 3.05 | 3.04 |
Respiration (μM O2) | 2.46 | 2.80 | 7.90 | 8.73 |
BGEa | 0.09 | 0.10 | 0.28 | 0.26 |
DMSP contribution to C demand (%) | 6 | 5 | 5 | 4 |
[35S]DMSP sulfur assimilation efficiency into TCA insolubles (%) | 29 | 29 | 13 | 12 |
DMSP contribution to S demand (%)b | 860 | 690 | 102 | 95 |
Assuming the BGE = BBP/(BBP + respiration), a respiratory quotient of 1, and that nonbacterial respiration was negligible. If nonbacterial respiration was significant, actual bacterial growth efficiencies would be higher than calculated. BBP, bacterial biomass production; BGE, bacterial growth efficiency.
Assuming a C:S ratio of 240 (2).
Also shown is the proportion of the bacterial C and S demands that could be derived from the measured DMSP consumption rates.