Da. Vroblesky et al., INFLUENCE OF ELECTRON-DONOR ON THE MINIMUM SULFATE CONCENTRATION REQUIRED FOR SULFATE REDUCTION IN A PETROLEUM HYDROCARBON-CONTAMINATED AQUIFER, Environmental science & technology, 30(4), 1996, pp. 1377-1381
Fluctuations in the availability of electron donor (petroleum hydrocar
bons) affected the competition between sulfate-reducing bacteria (SRB)
and methanogenic bacteria (MB) for control of electron flow in a petr
oleum hydrocarbon-contaminated aquifer. The data suggest that abundant
electron donor availability allowed MB to sequester a portion of the
electron flow even when sulfate was present in sufficient concentratio
ns to support sulfate reduction. For example, in an area of abundant e
lectron-donor availability, SRB appeared to be unable to sequester the
electron flow from MB in the presence of 1.4 mg/L sulfate. The data a
lso suggest that when electron-donor availability was limited, SRB out
competed MB for available substrate at a lower concentration of sulfat
e than when electron donor was plentiful. For example, in an area of l
imited electron-donor availability, SRB appeared to maintain dominance
of electron flow at sulfate concentrations less than 1 mg/L. The pres
ence of abundant electron donor and a limited amount of sulfate reduce
d competition for available substrate, allowing both SRB and MB to met
abolize available substrates concurrently.