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PeiW (UniProtKB Q7LYX0) and PeiP (UniProtKB Q77WJ4) are the two major pseudomurein endoisopeptidases (Pei) that are known to cleave pseudomurein cell-wall sacculi of the members of the methanogenic ordersMethanobacterialesandMethanopyrales. Both enzymes, originating from prophages specific for some methanogenic archaeal species, hydrolyze the (Ala)-Lys bond of the peptide linker between adjacent pseudomurein layers. Because lysozyme is not able to cleave the pseudomurein cell wall, the enzymes are used in protoplast preparation and in DNA isolation from pseudomurein cell-wall-containing methanogens. Moreover, PeiW increases the probe permeability ratio and enables fluorescence in situ hybridization (FISH) and catalyzed reporter deposition (CARD-) FISH experiments to be performed on these methanogens.

Desulfovibrio gigas NCIMB 9332 cells grown in ethanol-containing medium with 0.1 mu M tungstate contained a benzylviologen-linked aldehyde oxidoreductase, The enzyme was purified to electrophoretic homogeneity and found to be a homodimer with a subunit M(r) of 62,000, It contained 0.68 a 0.08 W, 4.8 Fe, and 3.2 +/- 0.2 labile S per subunit, After acid iodine oxidation of the purified enzyme, a fluorescence spectrum typical for form A of molybdopterin was obtained, Acetahdehyde, propionaldehyde, and benzaldehyde were excellent substrates, with apparent K-m values of 12.5, 10.8, and 20 mu M, respectively, The natural electron acceptor is not yet known; benzylviologen was used as an artificial electron acceptor (apparent K-m, 0.55 mM), The enzyme was activated by potassium ions and strongly inhibited by cyanide, arsenite, and iodoacetate, In the as-isolated enzyme, electron paramagnetic resonance studies readily detected W(V) as a complex signal with g values in the range of 1.84 to 1.97, The dithionite-reduced enzyme exhibited a broad signal at low temperature,vith g = 2.04 and 1.92; this is indicative of a [4Fe-4S](1+) cluster interacting with a second paramagnet, possibly the S = 1 system of W(TV), Until now W-containing aldehyde oxidoreductases had only been found in two Clostridium strains and two hyperthermophilic archaea, The D. gigas enzyme is the first example of such an enzyme in a gram-negative bacterium.

Desulfovibrio gigas NCIMB 9332 cells grown in ethanol-containing medium with 0.1 mu M tungstate contained a benzylviologen-linked aldehyde oxidoreductase, The enzyme was purified to electrophoretic homogeneity and found to be a homodimer with a subunit M(r) of 62,000, It contained 0.68 a 0.08 W, 4.8 Fe, and 3.2 +/- 0.2 labile S per subunit, After acid iodine oxidation of the purified enzyme, a fluorescence spectrum typical for form A of molybdopterin was obtained, Acetahdehyde, propionaldehyde, and benzaldehyde were excellent substrates, with apparent K-m values of 12.5, 10.8, and 20 mu M, respectively, The natural electron acceptor is not yet known; benzylviologen was used as an artificial electron acceptor (apparent K-m, 0.55 mM), The enzyme was activated by potassium ions and strongly inhibited by cyanide, arsenite, and iodoacetate, In the as-isolated enzyme, electron paramagnetic resonance studies readily detected W(V) as a complex signal with g values in the range of 1.84 to 1.97, The dithionite-reduced enzyme exhibited a broad signal at low temperature,vith g = 2.04 and 1.92; this is indicative of a [4Fe-4S](1+) cluster interacting with a second paramagnet, possibly the S = 1 system of W(TV), Until now W-containing aldehyde oxidoreductases had only been found in two Clostridium strains and two hyperthermophilic archaea, The D. gigas enzyme is the first example of such an enzyme in a gram-negative bacterium.

Growth of Desulfovibrio gigas NCIMB 9332 in mineral, vitamin-supplemented media with ethanol as substrate was strongly stimulated by the addition of tungstate (optimal level approximately 10(-7) M). At suboptimal tungstate concentrations, up to 1.0 mM acetaldehyde was detected in the culture supernatant and growth was slow. Omission of both tungstate and molybdate from the media prevented growth and ethanol utilization. Tung state-deprived cultures that were grown on lactate had much lower aldehyde dehydrogenase (benzylviologen as acceptor; BV-AlDH) levels than tungstate-supplemented cultures. These data suggest that tungstate is required for the synthesis of active BV-AlDH. The characteristics of the enzyme activities in cell-free extracts show that the BV-AlDH activity present in tungstate-supplemented cultures is not due to the recently characterized molybdenum-containing aldehyde dehydrogenase of D. gigas. Out of 13 other strains of ethanol-oxidizing, gram-negative, sulfate-reducing bacteria tested, most strains grew well with either tungstate or molybdate supplementation. In contrast to a recent report, good growth on ethanol of two D. baculatus (Desulfomicrobium) strains (DSM 1741 and DSM 1743) was observed.

Growth of Desulfovibrio gigas NCIMB 9332 in mineral, vitamin-supplemented media with ethanol as substrate was strongly stimulated by the addition of tungstate (optimal level approximately 10(-7) M). At suboptimal tungstate concentrations, up to 1.0 mM acetaldehyde was detected in the culture supernatant and growth was slow. Omission of both tungstate and molybdate from the media prevented growth and ethanol utilization. Tung state-deprived cultures that were grown on lactate had much lower aldehyde dehydrogenase (benzylviologen as acceptor; BV-AlDH) levels than tungstate-supplemented cultures. These data suggest that tungstate is required for the synthesis of active BV-AlDH. The characteristics of the enzyme activities in cell-free extracts show that the BV-AlDH activity present in tungstate-supplemented cultures is not due to the recently characterized molybdenum-containing aldehyde dehydrogenase of D. gigas. Out of 13 other strains of ethanol-oxidizing, gram-negative, sulfate-reducing bacteria tested, most strains grew well with either tungstate or molybdate supplementation. In contrast to a recent report, good growth on ethanol of two D. baculatus (Desulfomicrobium) strains (DSM 1741 and DSM 1743) was observed.

Desulfovibrio gigas NCIMB 9332 cells grown in ethanol-containing medium with 0.1 mu M tungstate contained a benzylviologen-linked aldehyde oxidoreductase, The enzyme was purified to electrophoretic homogeneity and found to be a homodimer with a subunit M(r) of 62,000, It contained 0.68 a 0.08 W, 4.8 Fe, and 3.2 +/- 0.2 labile S per subunit, After acid iodine oxidation of the purified enzyme, a fluorescence spectrum typical for form A of molybdopterin was obtained, Acetahdehyde, propionaldehyde, and benzaldehyde were excellent substrates, with apparent K-m values of 12.5, 10.8, and 20 mu M, respectively, The natural electron acceptor is not yet known; benzylviologen was used as an artificial electron acceptor (apparent K-m, 0.55 mM), The enzyme was activated by potassium ions and strongly inhibited by cyanide, arsenite, and iodoacetate, In the as-isolated enzyme, electron paramagnetic resonance studies readily detected W(V) as a complex signal with g values in the range of 1.84 to 1.97, The dithionite-reduced enzyme exhibited a broad signal at low temperature,vith g = 2.04 and 1.92; this is indicative of a [4Fe-4S](1+) cluster interacting with a second paramagnet, possibly the S = 1 system of W(TV), Until now W-containing aldehyde oxidoreductases had only been found in two Clostridium strains and two hyperthermophilic archaea, The D. gigas enzyme is the first example of such an enzyme in a gram-negative bacterium.

Growth of Desulfovibrio gigas NCIMB 9332 in mineral, vitamin-supplemented media with ethanol as substrate was strongly stimulated by the addition of tungstate (optimal level approximately 10(-7) M). At suboptimal tungstate concentrations, up to 1.0 mM acetaldehyde was detected in the culture supernatant and growth was slow. Omission of both tungstate and molybdate from the media prevented growth and ethanol utilization. Tung state-deprived cultures that were grown on lactate had much lower aldehyde dehydrogenase (benzylviologen as acceptor; BV-AlDH) levels than tungstate-supplemented cultures. These data suggest that tungstate is required for the synthesis of active BV-AlDH. The characteristics of the enzyme activities in cell-free extracts show that the BV-AlDH activity present in tungstate-supplemented cultures is not due to the recently characterized molybdenum-containing aldehyde dehydrogenase of D. gigas. Out of 13 other strains of ethanol-oxidizing, gram-negative, sulfate-reducing bacteria tested, most strains grew well with either tungstate or molybdate supplementation. In contrast to a recent report, good growth on ethanol of two D. baculatus (Desulfomicrobium) strains (DSM 1741 and DSM 1743) was observed.