The source of hydrogen sulfide in anoxic sediment

Putrefactive hydrogen sulfide production in the upper 4 cm of sediment in two small freshwater and eutrophic Southeast Michigan, U.S.A., lakes ranged from 0.13 to 1.51 with an average of 0.46 mg S l-1 day-1. Sulfate reductive production of hydrogen sulfide at the same sites ranged from 0.7 to 3.2 with an average of 1.54 mg S l-1 day-1. Putrefactive hydrogen sulfide production represented 5.1-53% (average of 18.3-27.6%) of the total hydrogen sulfide produced at the two lakes over an April-October study period. 35S labeled substrates were used to estimate hydrogen sulfide production rates.Proteolytic bacteria averaged 2.2 x 104 cells ml-1 sediment whereas sulfate reducers averaged 4.8 x 102 cells ml-1 sediment. Putrefactive hydrogen sulfide production correlated highly with numbers of proteolytic bacteria (r2 = 0.84) but the correlation between sulfate reduction and sulfate reducing bacteria was low (r2 = 0.13).Interstitial soluble inorganic sulfate, protein and organic carbon were not closely correlated with hydrogen sulfide production rates or bacteria enumeration results. Natural substrate concentrations (Sn) used to estimate hydrogen sulfide production were supported by kinetic bioassay results.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/25926/1/0000489.pd