Sulfate Reduction by a Desulfovibrio Species Isolated from Sheep Rumen1

Abstract

Several dissimilatory, sulfate-reducing bacteria were isolated from the rumen fluid of sheep fed purified diets containing sulfate. One isolate, strain D, was selected for characterization. This organism is a nonsporeforming, obligately anaerobic, mesophilic, nonmotile, gram-negative, straight rod. Cell-free extracts show absorption maxima for cytochrome c3 and desulfoviridin, characteristic of Desulfovibrio. Carbohydrates, as a sole carbon source, will support growth. Lactate supports growth in the presence of sulfate, not in its absence, whereas glucose or pyruvate support growth either in the presence or absence of sulfate. The isolate has a deoxyribonucleic acid base composition of 61.2% guanine plus cytosine, which is similar to that of several other species of Desulfovibrio; however, it differs from previously described species in morphology, motility, and carbon source utilization. Cell-free extracts of this bacterium exhibit adenosine 5'-triphosphate-sulfurylase, adenosine-5'-phosphosulfate-reductase, and hydrogenase activity. After incubation of cell-free extracts with adenine 5'-triphosphate and 3SO042-, adenosine-5'-phosphosulfate rather than 3'-phosphoadenosine-5'-phosphosulfate was shown to be labeled, indicating that the pathway of sulfate reduction in this organism is similar to that of other dissimilatory sulfate reducers. This is the first report of a Desulfovibrio sp. isolated from the rumen.

Ferric citrate, nitrate, saponin and their combinations affect in vitro ruminal fermentation, production of sulphide and methane and abundance of select microbial populations

“…This premise is consistent with a previous study where the addition of nitrate had a stimulatory effect on the subsequent reduction in sulphate (Sørensen 1982). Decreased sulphide concentration in the presence of ferric citrate, alone and in combination, was consistent with our previous report (Wu et al 2016), and it can be explained, at least partially, by the ability of Desulfovibrio spp., which was reported as the prevalent SRB in the rumen, to reduce ferric iron (Huisingh et al 1974). Drewnoski et al (2014) also reported a decrease in H 2 S gas production in the rumen of beef cattle when ferric citrate was added to the diet.…”

“…The genus Desulfovibrio was reported as the prevalent SRB in the rumen, and some species of this genus could reduce ferric iron (Huisingh et al 1974). Thus, the abundance of Desulfovibrio was quantified to evaluate the effect of the three inhibitors on this genus.…”

Establishment of hydrogen-utilizing bacteria in the rumen of the newborn lamb

“…They establish very early after birth in the rumen of lambs raised under conventional conditions [4,5], in parallel with cellulolytic bacteria. Among the other microbial groups capable of hydrogen utilization, sulfate-reducing bacteria have been reported from the rumen of sheep and cattle, while acetogenic bacteria were isolated from the rumen of steers [6][7][8][9]. The aim of the present work was to follow the establishment of the different H2-utilizing bacteria in the rumen microflora of newborn lambs.…”

An unusual strain of Desulfovibrio sp. from an Antarctic lake

“…However, anomalous strains have been reported in the literature over this period [e.g. 2,3,5,12,[15][16][17][18]. Some reservations on the present system have been expressed by Postgate [1,5].…”