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Kellum R, Drake HL. Effects of carbon monoxide on one-carbon enzymes and energetics ofClostridium thermoaceticum. FEMS Microbiol Lett 1986. [DOI: 10.1111/j.1574-6968.1986.tb01345.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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53
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Ivey DM, Ljungdahl LG. Purification and characterization of the F1-ATPase from Clostridium thermoaceticum. J Bacteriol 1986; 165:252-7. [PMID: 2867087 PMCID: PMC214397 DOI: 10.1128/jb.165.1.252-257.1986] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The F1 portion of the H+-ATPase from Clostridium thermoaceticum was purified to homogeneity by solubilization at low ionic strength, ion-exchange chromatography, and gel filtration. The last indicated the Mr to be 370,000. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the pure enzyme revealed four bands with Mr corresponding to 60,000, 55,000, 37,000, and 17,000 in an apparent molar ratio of 3:3:1:1. The purified enzyme would bind to stripped membranes to reconstitute dicyclohexylcarbodiimide-sensitive ATPase activity. Phosphohydrolase activity, measured at 58 degrees C, was optimal at pH 8.5. In the presence of a 1 mM excess of Mg2+ over the concentration of ATP, the Km for ATP was 0.4 mM, and the Vmax was 6.7 mumol min-1 mg-1. Unlike the membrane-bound F1F0 complex, the F1-ATPase was relatively insensitive to the inhibitors dicyclohexylcarbodiimide and tributyltin chloride. Both the complex and the F1-ATPase were inhibited by quercetin, azide, 7-chloro-4-nitro-benz-2-oxa-1,3-diazole, and free magnesium, and both were stimulated by primary alcohols and sulfite. In whole cells, the F1F0-ATPase catalyzed the synthesis of ATP in response to a pH gradient.
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Abstract
Methanogenic and acetogenic bacteria metabolize carbon monoxide, methanol, formate, hydrogen and carbon dioxide gases and, in the case of certain methanogens, acetate, by single-carbon (C1) biochemical mechanisms. Many of these reactions occur while the C1 compounds are linked to pteridine derivatives and tetrapyrrole coenzymes, including corrinoids, which are used to generate, reduce, or carbonylate methyl groups. Several metalloenzymes, including a nickel-containing carbon monoxide dehydrogenase, are used in both catabolic and anabolic oxidoreductase reactions. We propose biochemical models for coupling carbon and electron flow to energy conservation during growth on C1 compounds based on the carbon flow pathways inherent to acetogenic and methanogenic metabolism. Biological catalysts are therefore available which are comparable to those currently in use in the Monsanto process. The potentials and limitations of developing biotechnology based on these organisms or their enzymes and coenzymes are discussed.
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55
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Kühn W, Gottschalk G. Characterization of the cytochromes occurring in Methanosarcina species. EUROPEAN JOURNAL OF BIOCHEMISTRY 1983; 135:89-94. [PMID: 6309519 DOI: 10.1111/j.1432-1033.1983.tb07621.x] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Several members of the genus Methanosarcina were investigated by room-temperature and low-temperature difference spectroscopy for the presence of cytochromes. In combination with potentiometric titrations two membrane-bound b-cytochromes and one membrane-bound c-cytochrome could be detected in cells grown on methanol or trimethylamine. Very probably acetate-grown cells contained an additional cytochrome b. The midpoint potentials of the two b-type cytochromes were Em1 = -325 mV and Em2 = -183 mV, respectively. The additional b cytochrome formed during growth on acetate exhibited a midpoint potential of Em3 = -250 mV.
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Drake HL. Demonstration of hydrogenase in extracts of the homoacetate-fermenting bacterium Clostridium thermoaceticum. J Bacteriol 1982; 150:702-9. [PMID: 7040339 PMCID: PMC216419 DOI: 10.1128/jb.150.2.702-709.1982] [Citation(s) in RCA: 64] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Cell-free extracts of the homoacetate-fermenting bacterium Clostridium thermoaceticum were shown to catalyze the hydrogen-dependent reduction of various artificial electron acceptors. The activity of the hydrogenase was optimal at pH 8.5 to 9 and was extremely sensitive to aeration. EDTA did not significantly reduce the liability of the enzymic activity to oxidation (aeration). At 50 degrees C, when both methyl viologen and hydrogen were at saturating concentrations with respect to hydrogenase, the specific activity of cell-free extracts approximated 4 mumol of H2 oxidized per min per mg of protein; fourfold higher specific activities were obtained when benzyl viologen was utilized as an electron acceptor. Activity stains of polyacrylamide gels demonstrated the presence of a single hydrogenase band, suggesting that the catalytic activity in cell extracts was due to a single enzyme. The activity was stable for at least 32 min at 55 degrees C but was slowly inactivated at 70 degrees C. NAD, NADP, flavin adenine dinucleotide, flavin mononucleotide, and ferredoxin were not significantly reduced, but possible reduction of the particulate b-type cytochrome of C. thermoaceticum was observed. NaCl, sodium dodecyl sulfate, iodoacetamide, and CO were shown to inhibit catalysis. A kinetic study is presented, and the possible physiologic roles for hydrogenase in C. thermoaceticum ar discussed.
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Barnabas J, Schwartz RM, Dayhoff MO. Evolution of major metabolic innovations in the precambrian. ORIGINS OF LIFE 1982; 12:81-91. [PMID: 7133672 DOI: 10.1007/bf00926914] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
A combination of the information on the metabolic capabilities of prokaryotes with a composite phylogenetic tree depicting an overview of prokaryote evolution based on the sequences of bacterial ferredoxin, 2Fe-2S ferredoxin, 5S ribosomal RNA, and c-type cytochromes shows three zones of major metabolic innovation in the Precambrian. The middle of these, which reflects the genesis of oxygen-releasing photosynthesis and aerobic respiration, links metabolic innovations of the anaerobic stem on the one hand and, on the other, proliferation of aerobic bacteria and the symbiotic associations leading to the eukaryotes. We consider especially those pathways where information on the structure of the enzymes is known. Halobacterium and Thermoplasma (archaebacteria) do not belong to a totally independent line on the basis of the composite tree but branch from the eukaryote cytoplasmic line.
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59
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Collins MD, Jones D. Distribution of isoprenoid quinone structural types in bacteria and their taxonomic implication. Microbiol Rev 1981; 45:316-54. [PMID: 7022156 PMCID: PMC281511 DOI: 10.1128/mr.45.2.316-354.1981] [Citation(s) in RCA: 517] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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60
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Ljungdahl LG, Bryant F, Carreira L, Saiki T, Wiegel J. Some aspects of thermophilic and extreme thermophilic anaerobic microorganisms. BASIC LIFE SCIENCES 1981; 18:397-419. [PMID: 7271714 DOI: 10.1007/978-1-4684-3980-9_23] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
In this presentation, we have discussed that the acetogenic thermophilic bacterium, Clostridium thermoaceticum, ferments glucose almost quantitatively to acetate. That part of the acetate is formed from CO2, which functions as the electron sink. We have demonstrated that enzymes in the acetate formation contain trace elements such as iron, cobalt, nickel, selenium and tungsten. Furthermore, we have indicated that this bacterium must have an electron transport system, which is not yet completely understood. With Clostridium thermohydrosulfuricum we have obtained results which indicate that this thermophile may selectively produce proteins dependent on the environmental temperature. We have presented a new bacterium, Thermoanaerobacter ethanolicus, which ferments several sugars including starch, cellobiose, and xylose to ethanol. We have demonstrated the existence in a thermal environment of anaerobic bacteria that grow at temperatures of around 90 degrees C and which are capable of fermenting diverse substrates such as lactate, glucose, and cellulose.
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61
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Drake H, Hu S, Wood H. Purification of carbon monoxide dehydrogenase, a nickel enzyme from Clostridium thermocaceticum. J Biol Chem 1980. [DOI: 10.1016/s0021-9258(20)79682-1] [Citation(s) in RCA: 126] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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62
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Yang SS, Ljungdahl LG, Dervartanian DV, Watt GD. Isolation and characterization of two rubredoxins from Clostridium thermoaceticum. BIOCHIMICA ET BIOPHYSICA ACTA 1980; 590:24-33. [PMID: 6243972 DOI: 10.1016/0005-2728(80)90143-7] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Two rubredoxins with similar molecular weights (about 6000) have been purified from Clostridium thermoaceticum, a thermophile and strict anaerobe. They exhibit minor differences in several properties like elution pattern from DEAE-cellulose column, isoelectric point, amino acid composition, absorption and EPR spectra and redox potential. Their chemical and physical properties are similar to those of other rubredoxins from anaerobic microorganisms.
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WURM RAINER, RENZ PAUL, HECKMANN GERNOT. THE BIOSYNTHESIS OF THE VITAMIN B12-ANALOG 5-ETHOXYBENZIMIDAZOLYLCOBAMIDE IN CLOSTRIDIUM THERMOACETICUM. FEMS Microbiol Lett 1980. [DOI: 10.1111/j.1574-6941.1980.tb01566.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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64
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Yang SS, Ljungdahl LG, Lund G. Isolation of uroporphyrin III from Clostridium thermoaceticum. Biochem Biophys Res Commun 1979; 90:575-81. [PMID: 508322 DOI: 10.1016/0006-291x(79)91274-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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65
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Clarke DJ, Morris JG. The proton-translocating adenosine triphosphatase of the obligately anaerobic bacterium Clostridium pasteurianum. 2. ATP synthetase activity. EUROPEAN JOURNAL OF BIOCHEMISTRY 1979; 98:613-20. [PMID: 39759 DOI: 10.1111/j.1432-1033.1979.tb13223.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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66
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Diekert GB, Thauer RK. Carbon monoxide oxidation by Clostridium thermoaceticum and Clostridium formicoaceticum. J Bacteriol 1978; 136:597-606. [PMID: 711675 PMCID: PMC218584 DOI: 10.1128/jb.136.2.597-606.1978] [Citation(s) in RCA: 204] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Cultures of Clostridium formicoaceticum and C. thermoaceticum growing on fructose and glucose, respectively, were shown to rapidly oxidize CO to CO(2). Rates up to 0.4 mumol min(-1) mg of wet cells(-1) were observed. Carbon monoxide oxidation by cell suspensions was found (i) to be dependent on pyruvate, (ii) to be inhibited by alkyl halides and arsenate, and (iii) to stimulate CO(2) reduction to acetate. Cell extracts catalyzed the oxidation of carbon monoxide with methyl viologen at specific rates up to 10 mumol min(-1) mg of protein(-1) (35 degrees C, pH 7.2). Nicotinamide adenine dinucleotide, nicotinamide adenine dinucleotide phosphate and ferredoxin from C. pasteurianum were ineffective as electron acceptors. The catalytic mechanism of carbon monoxide oxidation was "ping-pong," indicating that the enzyme catalyzing carbon monoxide oxidation can be present in an oxidized and a reduced form. The oxidized form was shown to react reversibly with cyanide, and the reduced form was shown to react reversibly with alkyl halides: cyanide inactivated the enzyme only in the absence of carbon monoxide, and alkyl halides inactivated it only in the presence of carbon monoxide. Extracts inactivated by alkyl halides were reactivated by photolysis. The findings are interpreted to indicate that carbon monoxide oxidation in the two bacteria is catalyzed by a corrinoid enzyme and that in vivo the reaction is coupled with the reduction of CO(2) to acetate. Cultures of C. acidi-urici and C. cylindrosporum growing on hypoxanthine were found not to oxidize CO, indicating that clostridia mediating a corrinoid-independent total synthesis of acetate from CO(2) do not possess a CO-oxidizing system.
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68
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Dorn M, Andreesen JR, Gottschalk G. Fumarate reductase of Clostridium formicoaceticum. A peripheral membrane protein. Arch Microbiol 1978; 119:7-11. [PMID: 214050 DOI: 10.1007/bf00407920] [Citation(s) in RCA: 35] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
When Clostridium formicoaceticum was grown on fumarate or L-malate crude cell extracts contained a high fumarate reductase activity. Using reduced methyl viologen as electron donor the specific activity amounted to 2-3.5 U per mg of protein. Reduced benzyl viologen, FMNH2 and NADH could also serve as electron donors but the specific activities were much lower. The NADH-dependent activity was strictly membrane-bound and rather labile. Its specific activity did not exceed 0.08 U per mg of particle protein. Fumarate reductase activity was also found in cells of C. formicoaceticum grown on fructose, gluconate, glutamate and some other substrates. The methyl viologen-dependent fumarate reductase activity could almost completely be measured with intact cells whereas only about 25% of the cytoplasmic acetate kinase activity was detected with cell suspensions. The preparation of spheroplasts from cells of C. formicoaceticum in 20 mM HEPES-KOH buffer containing 0.6 M sucrose and 1 mM dithioerythritol resulted in the specific release of 88% of the fumarate reductase activity into the spheroplast medium. Only small amounts of the cytoplasmic proteins malic enzyme and acetate kinase were released during this procedure. There results indicate a peripheral location of the fumarate reductase of C. formicoaceticum on the membrane.
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69
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Laanbroek HJ, Stal LH, Veldkamp H. Utilization of hydrogen and formate by Campylobacter spec. under aerobic and anaerobic conditions. Arch Microbiol 1978; 119:99-102. [PMID: 718373 DOI: 10.1007/bf00407935] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
A free-living aspartate-fermenting Campylobacter spec. was shown to utilize hydrogen produced in mixed culture by Clostridium cochlearium from glutamate. Resting cells of Campylobacter were shown to reduce aspartate, fumarate and malate as well as nitrate, nitrite, hydroxylamine, sulphite, thiosulphate and elemental sulphur with molecular hydrogen. Growth of Campylobacter spec. was demonstrated with formate as electron donor and nitrate, thiosulphate, elemental sulphur or oxygen as electron acceptor in the presence of acetate as carbon source.
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70
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Reddy CA, Peck HD. Electron transport phosphorylation coupled to fumarate reduction by H2- and Mg2+-dependent adenosine triphosphatase activity in extracts of the rumen anaerobe Vibrio succinogenes. J Bacteriol 1978; 134:982-91. [PMID: 149114 PMCID: PMC222347 DOI: 10.1128/jb.134.3.982-991.1978] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Vibrio succinogenes, an anaerobic bacterium, obtains its energy for growth from H2 or formate oxidation coupled to the reduction of fumarate to succinate. Membrane preparations have been obtained from this organism that catalyze the synthesis of ATP during H2 oxidation coupled to fumarate reduction. Esterification of orthophosphate is dependent on electron transfer, as evidenced by the requirement for both H2 and fumarate. Phosphorylation is also dependent on ADP and is destroyed by boiling the membrane preparations. H2 utilized for fumarate reduction and succinate formed are stoichiometric. The phosphorylation is markedly uncoupled by pentachlorophenol and gramicidin, but to a lesser extent by dinitrophenol and methyl viologen. 2-n-Heptyl-4-hydroxyquinoline-N-oxide causes severe inhibition of H2 oxidation as well as phosphorylation, but oligomycin or antimycin A has no demonstrable effect. Among several electron acceptors tested, significant phosphorylation is observed only with fumarate. A Mg2+-dependent adenosine triphosphatase activity is present in both the membrane and soluble protein fractions. Highest activity is obtained with ATP as the substrate, and considerably less activity is obtained with other nucleoside triphosphates. The possibility that phosphorylation during "fumarate respiration" may play an important physiological role in the growth of many anaerobic and facultatively anaerobic bacteria is discussed.
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71
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Dorn M, Andreesen JR, Gottschalk G. Fermentation of fumarate and L-malate by Clostridium formicoaceticum. J Bacteriol 1978; 133:26-32. [PMID: 618841 PMCID: PMC221972 DOI: 10.1128/jb.133.1.26-32.1978] [Citation(s) in RCA: 83] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The fermentation of fumarate and L-malate by Clostridium formicoaceticum was investigated. Growing and nongrowing cells degraded fumarate by dismutation to succinate, acetate, and CO2; on the other hand, only small amounts of succinate were detected when the organism was grown on L-malate. This dicarboxylic acid was mainly converted to acetate and CO2. The fermentation balances were modified if bicarbonate or formate were present in the medium. When C. formicoaceticum was grown in the presence of both dicarboxylic acids, fumarate was consumed before L-malate. The latter was mainly converted to acetate, whereas fumarate was fermented to acetate and succinate. Molar growth yields were determined to be 6 g of dry weight per mol of fumarate and 8 g of dry weight per mol of L-malate fermented.
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72
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Leonhardt U, Andreesen JR. Some properties of formate dehydrogenase, accumulation and incorporation of 185W-tungsten into proteins of Clostridium formicoaceticum. Arch Microbiol 1977; 115:277-84. [PMID: 23733 DOI: 10.1007/bf00446453] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Formate dehydrogenase of Clostridium formicoaceticum used only methyl and benzyl viologen, but not NAD as electron acceptor. The S0.5 values were 0.9 X 10(-4) M for formate and 5.8 X 10(-3) M for methyl viologen. Using potassium phosphate buffer a pH-optimum of 7.9 was observed. The initial velocity of the formate dehydrogenase activity reached a maximum at 70 degrees C, whereas the activity was stable only up to 50 degrees C. The level of formate dehydrogenase in C. formicoaceticum was increased to its maximum when 10(-6) M selenite and 10(-7) M tungstate were added to a synthetic medium. Addition of molybdate instead of tungstate did not increase the level of formate dehydrogenase. 185W-tungsten was concentrated about 100-fold by C. formicoaceticum; molybdate had no major effect on the uptake of tungsten. 185W-tungsten was found almost exclusively in the soluble fluid and was predominantly recovered after chromatography in a protein of about 88000 molecular weight. Occasionally a labelled protein of low molecular weight was observed. Again molybdate added even in high molar excess did not influence the labelling pattern. No radioactivity peak could be obtained at the elution peak of formate dehydrogenase activity. The extreme instability of formate dehydrogenase prevented further purification.
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73
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Yang SS, Ljungdahl LG, LeGall J. A four-iron, four-sulfide ferredoxin with high thermostability from Clostridium thermoaceticum. J Bacteriol 1977; 130:1084-90. [PMID: 863852 PMCID: PMC235330 DOI: 10.1128/jb.130.3.1084-1090.1977] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
A ferredoxin containing only one [Fe4S4] cluster was purified from Clostridium thermoaceticum. It has a molecular weight of about 7,300, a partial specific volume of 0.67, and an isoelectric point of 3.25. Its absorption spectrum has two maxima at 390 nm (epsilon = 16.8 X 10(3)M-1cm-1) and at 280 nm (epsilon = 24.2 X 10(3)M-1cm-1). The absorption at 390 nm is almost half that of other clostridial ferredoxins, which have two [Fe4S4] clusters, and is similar to other ferredoxins with only one [Fe4S4] cluster. The ferredoxin had high thermal stability and retained over 50% of its activity after treatment at 80 degrees C. It functions in the transfer of electrons from pyruvate to nicotinamide adenine dinucleotide phosphate (NADP), which indicates the presence of pyruvate:ferredoxin oxidoreductase and reduced ferredoxin-NADP reductase in C, thermoaceticum. NADPH is used in the synthesis of acetate from CO2 in this organism.
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74
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75
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Thauer RK, Jungermann K, Decker K. Energy conservation in chemotrophic anaerobic bacteria. BACTERIOLOGICAL REVIEWS 1977. [PMID: 860983 DOI: 10.1128/mmbr.41.1.100-180.1977] [Citation(s) in RCA: 1103] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
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76
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Thauer RK, Jungermann K, Decker K. Energy conservation in chemotrophic anaerobic bacteria. BACTERIOLOGICAL REVIEWS 1977; 41:100-80. [PMID: 860983 PMCID: PMC413997 DOI: 10.1128/br.41.1.100-180.1977] [Citation(s) in RCA: 1326] [Impact Index Per Article: 28.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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77
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Wiegel J, Schlegel H. Leucine biosynthesis: effect of branched-chain amino acids and threonine on synthase activity from aerobic and anaerobic microorganisms. BIOCHEM SYST ECOL 1977. [DOI: 10.1016/0305-1978(77)90001-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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78
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Abstract
An obligately anaerobic bacterium, Eubacterium lentum, was shown to contain cytochromes a, b, and c and a carbon monoxide-binding pigment. Extracts of cells grown with hemin gave a typical absorption spectrum for cytochrome c with maxima at 424, 525, and 553 nm. Extracts from cells grown in the absence of hemin also had an absorption peak corresponding to cytochrome b (562 nm) in their reduced versus oxidized spectrum. Extraction of hemes and formation of pyridine hemochromes allowed quantitation of protoheme IX and heme c. Large amounts of cytochrome c masked the presence of cytochrome b in cells grown in medium containing hemin. When cells were grown in the presence of 50 mM nitrate, cytochrome A (606 nm) was detected. In anaerobic extracts of cells grown either with or without nitrate, cytochromes b and c were reduced by formate and oxidized by NO3. Cytochrome a appeared to be partially oxidized by NO3 and completely oxidized by air.
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79
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Macy J, Probst I, Gottschalk G. Evidence for cytochrome involvement in fumarate reduction and adenosine 5'-triphosphate synthesis by Bacteroides fragilis grown in the presence of hemin. J Bacteriol 1975; 123:436-42. [PMID: 1150622 PMCID: PMC235746 DOI: 10.1128/jb.123.2.436-442.1975] [Citation(s) in RCA: 80] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Growth of Bacteroides fragilis subsp. fragilis on glucose was very much stimulated by the addition of hemin (2 mg/liter) to the medium. The generation time decreased from 8 to 2 h, and the molar growth yield increased from YM = 17.9 to YM = 47 g (dry weight) of cells per mol of glucose. In the absence of hemin, glucose was fermented to fumarate, lactate, and acetate. The cells did not contain detectable amounts of cytochromes or fumarate reductase. In the presence of hemin, the major products of fermentation were succinate, propionate, and acetate. A b-type cytochrome, possibly a c-type cytochrome, and a very active fumarate reductase were present in the cells. It is concluded from these results that hemin is required by B. fragilis to synthesize a functional fumarate reductase and that the hemin-dependent, enormous increase of the growth yield may be due to adenosine 5'-triphosphate production during reduction of fumarate to succinate.
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80
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Ljungdahl LG, Andreesen JR. Tungsten, a component of active formate dehydrogenase from Clostridium thermoacetium. FEBS Lett 1975; 54:279-82. [PMID: 1132514 DOI: 10.1016/0014-5793(75)80092-5] [Citation(s) in RCA: 45] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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