. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. sulfide added chloramphenicol control cycloheximide 50 100 hours 150 MSX stopped. B Figure 2. Effect of inhibitors on Solemya velum ammonia and sulfide fluxes. (A). Chloramphenicol ( mA/). an inhibitor of prokaryotic protein synthesis, blocked sulfide consumption. Cycloheximide ( mA/). an inhibitor of eukaryotic protein synthesis, had no effect. (B). Methionine sulfoximine (MSX. mA/). an inhibitor of ammonia assimilation, blocked ammonia uptake and resulted in ammonia excretion. Negative fluxes denote uptake from
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. sulfide added chloramphenicol control cycloheximide 50 100 hours 150 MSX stopped. B Figure 2. Effect of inhibitors on Solemya velum ammonia and sulfide fluxes. (A). Chloramphenicol ( mA/). an inhibitor of prokaryotic protein synthesis, blocked sulfide consumption. Cycloheximide ( mA/). an inhibitor of eukaryotic protein synthesis, had no effect. (B). Methionine sulfoximine (MSX. mA/). an inhibitor of ammonia assimilation, blocked ammonia uptake and resulted in ammonia excretion. Negative fluxes denote uptake from the medium. of symbiont metabolism decreased the sulfide-stimulated thiotaurine synthesis. The maintenance of free amino acid pools depended upon the presence of functioning symbi- onts, sulfide consumption, and host ammonia assimilation. Thus, sulfur-containing free amino acids also may be a link between cycling of nitrogen and sulfur in chemoautotrophic symbioses. The magnitude of changes in taurine and thiotaurine pools observed in the present study is sufficient for these amino acids to be physiologically significant sulfide storage compounds. In experiments in which clams were exposed to sulfide for 24 h, the increases in taurine and thiotaurine levels corresponded to synthesis rates of • g~' wet weight • h"' and jLtmol • g~' • h~', respectively. Since taurine contains one S atom and thiotaurine contains two S atoms, this corresponds to a potential sulfide incor- poration rate of ;u,mol • g~' • h~'. The average rate of whole animal sulfide consumption measured under the con- trol (no inhibitor) conditions was jumol • g • h '. which is similar to the sulfide consumption rate of Solemya reidi under similar experimental conditions (Anderson et al., 1987). Therefore, the contribution of taurine and thio-. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability -
Size: 1905px × 1312px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
