A comparison of methods for the quantification of bacterial sulfate reduction in coastal marine sediments

Abstract

Rates of bacterial sulfate reduction are calculated from the accumulation of reduced sulfur compounds in coastal sediments. The method is found to underestimate the in situ metabolism 10-fold because it neglects diffusional losses of produced sulfide. In relation to this result, the quantitative connection between the pyrite, HClextractable iron, and organic carbon contents of the sediments and the intensity of sulfate reduction are disussed. A comparison is made between colony counts of sulfate-reducing bacteria and the rate of sulfate reduction in coastal sediments. The number of bacteria is roughly proportional to their measured rate of metabolism both when different sediment types and different depths are compared. The colony counts, however, seem to underestimate the true numbers of sulfate reducers by 1000-fold or more.

Characterization of microbial activity in pockmark fields of the SW-Barents Sea

“…Sulfate reduction rates were determined using a modification of the whole core 197 35 SO 4 2-injection method (Jørgensen, 1978) where a TRIS and a TOT are the activities of the TRIS compounds and the total activity 215 of the injected 35 SO 4 2-, respectively, using the raw counts (given as counts per 216 minute, cpm) from the scintillation counter; t is the incubation time and ρ SED the 217 porosity of the sediment (mL porewater cm -3 sediment). SO 4 2-is seawater SO 4 2-218 concentration, which was set to 28 mM for all samples, because there was no 219 measurable down-core depletion of porewater SO 4 2-concentrations in any of our 220 samples.…”

Rapid enumeration of sulphate-reducing bacteria from aquatic environments using real-time PCR

“…To enumerate SRB from natural environments, traditional culture-dependent methods have previously been employed. Several studies, however, have demonstrated the numbers of viable SRB in aquatic sediments are considerably underestimated when standard most-probable-number (MPN) methods are used with selective enrichment media (Gibson et al 1987, Jørgensen 1978.…”

On the contributions of David Cleaveland White, MD, PhD to microbial ecology: celebrating the life of a pioneer

“…During that formative year, he also founded the Center for Biomedical and Toxicological Research at Florida State University and continued to direct the center until 1985. Also, during this time, researchers were measuring in situ microbial activity like nitrate reduction rates (Henriksen, 1980), and it had already been possible to measure rates of sulfate reduction in sediments for a couple of years (Jorgensen, 1978), but Findlay et al (1985) illustrated that rates of metabolic activity can vary depending on the methods used to introduce labeled substrates and the amount of disturbance that was imparted on the system of interest.…”