Effect of inorganic sulfide on the growth and metabolism of Methanosarcina barkeri strain DM

Abstract

Minimal growth of Methanosarcina barkeri strain DM occurred when sulfide was omitted from the growth medium, and addition of either sodium sulfate or coenzyme M to sulfide-depleted media failed to restore growth. Optimal growth occurred in the presence of 1.25 mM added sulfide, giving a molar growth yield (YCH4) of 4.4 mg (dry weight) of cells per mmol of CH4 produced. Increasing sulfide to 12.5 mM led to a decrease in YCH4 (1.9 mg [dry weight]/mmol of CH4), in the specific growth rate and in the intracellular levels of adenosine triphosphate. However, the specific rate of methane production increased. The data suggested that at elevated sulfide levels (12.5 mM) the decrease in YCH4 might be a result of an increase in the relative energy needed for maintenance and of uncoupling of growth from energy production.

Biological Sulfate Reduction Using Molasses as a Carbon Source

“…Several researchers have reported toxicity as a result of increased levels of sulfide and un-ionized hydrogen sulfide (H 2 S), leading to diminished process performance (Fang et al, 1997;Karhadkar et al, 1987;and Maillacheruvu et al, 1993). Sulfide is inhibitory not only to methanogenesis (Karhadkar et al,1987;Koster et al, 1986;and Mountfort and Asher, 1979) but also to sulfate reduction (Okabe et al, 1995, andUberoi andBhattacharya, 1995). Koster et al (1986) reported 50% MPB activity inhibition at H 2 S concentrations of 250 mg/L S or total sulfide (TS) concentrations of 825 mg/L S, depending on the pH range.…”

Biological sulfide prestripping for metal and COD removal

“…Sulfate reducers, under certain circumstances, may out compete methanogens for the use of molecular hydrogen or other electron donors produced as a transient intermediate (Lovely and Klug, 1983;Lovely et al, 1982;and Phelps et al, 1985). It has also been found that increasing the levels of sulfide, at least to moderate levels, may increase the yield and/or growth rates of methanogenic organisms (Rudolfs and Amberg, 1952;Scherer and Sahm, 1981;and Mountfort and Asher, 1979). The presence of high levels of sulfate may influence the dynamic interaction, either because of providing a competitive pressure favoring the sulfate reducers, or perhaps by an inhibitory effect resulting from a high redox potential.…”

“…The basis for the improvement in organic degradation rate in the prestripped reactor is unclear at present, however several hypotheses can be advanced. First, Mountfort and Asher (1979) suggested that moderate levels of sulfide may improve methanogenic rates. The reactor sulfide level in the prestripped reactor was somewhat higher (6 mzyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA M) than in the copper added reactor (2.1 mM); the control reactor had 8 mM of soluble sulfides.…”

Thiosulfate, polythionates and elemental sulfur assimilation and reduction in the bacterial world

“…All methanogens can use sulfide as a sulfur source. Sulfate is generally not a sulfur source for methanogens [194,[197][198][199][200][201][202][203][204] [202,203]. Some species are also able to use cysteine [197,198,[203][204][205][206][207][208] or methionine [201,207].…”

“…Thus, the recent data suggest that methanogens have a variety of enzymes capable of reducing various sulfur compounds like elemental sulfur, sulfite and thiosulfate. Sulfate cannot be used as a significant source of sulfur by most methanogens [197][198][199][200][201][202][203][204]208,[216][217][218]. The marine environment is high in sulfate and it is reasonable to expect that some marine isolates of methanogens are able to reduce sulfate and use it as sulfur source.…”