%0 Journal Article %A Macfarlane, G. T. %A Russ, Moya A. %A Keith, S. M. %A Herbert, R. A. %T Simulation of Microbial Processes in Estuarine Sediments using Gel-stabilized Systems %D 1984 %J Microbiology, %V 130 %N 11 %P 2927-2933 %@ 1465-2080 %R https://doi.org/10.1099/00221287-130-11-2927 %I Microbiology Society, %X Gel-stabilized model systems have been developed which simulate the physico-chemical gradients found in estuarine sediments of the River Tay, Scotland. Depth profiles of E h and pH, and of concentrations of NH+ 4, NO− 2 and NO− 2 and dissolved O2 which developed within the gels were similar to those measured in situ in the sediments. The spatial distribution of populations of nitrifying, nitrate respiring and sulphate reducing bacteria in mature gels showed a good correlation with those recorded in the surface sediments of Kingoodie Bay in the Tay estuary. These data show that NH+ 4 oxidation by autotrophic nitrifying bacteria (Nitrosomonas and Nitrobacter) plays a significant role in the development of pH, NH+ 4, NO− 2 and NO− 3 gradients within the gels, indicating that similar processes may also operate in situ in these sediments. %U https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-130-11-2927