Seasonal temperature as a factor influencing bacterial sulfate reduction in a saltmarsh sediment

The population of sulfate-reducing bacteria in saltmarsh sediment was examined at monthly intervals by plate-counting and by determining the response of sulfate reduction rates to environmental temperature using³⁵SO ₄ ^2– . The sulfate reduction rate was shown to be related to temperature by an Arrhenius function.The temperature characteristic of the population of sulfate-reducing bacteria did not vary significantly with season, and was shown to be equivalent to 20.4 kcals mole^–1, a Q₁₀ of 3.5. Apart from one anomolous result, the monthly value for the Arrhenius constant also did not show any significant variation throughout the year. There was no seasonal trend of optimum temperature for sulfate reduction.The results suggested that, although environmental temperature was the dominant variable influencing sulfate reduction rates in the sediment, there was no detectable response or adaptation of the sulfate-reducing population to seasonally changing environmental temperature.