Ethanol formation from cellulose by thermophilic bacteria

Summary A wild coculture of obligately thermophilic bacteria, including only a single cellulolytic species Clostridium, ferments 2% crystalline cellulose and produces 4.6–5.1 g·l^–1 of ethanol at 55°–60° C; that is, 0.96–1.1 moles of ethanol from 1 mole of glucose equivalent of cellulose degraded. However, the ethanol yield decreases with increasing cellulose concentration. Ethanolacetic acid ratio varies around 1 and cannot be influenced by substrate concentration. However, this ratio can be influenced by changing pH and temperature. For the ethanol production from cellulose, neutral and weekly alkaline media with a pH of 7.0–8.0 and a temperature of 55° C are optimal. Experiments in which the coculture was subjected to high ethanol concentrations showed that higher concentrations of added ethanol (up to 20 g·l^–1) suppress cellulose degradation by 50% and inhibit the actual production of ethanol.     

Growth of Bacteria Degrading Naphthalene and Salicylate at Low Temperatures

A total of 58 bacterial strains degrading naphthalene and salicylate were isolated from soil samples polluted with oil products, collected in different regions of Russia during winter and summer. The isolates were assessed for their ability to grow at low temperatures (4, 8, and 15°C); bacteria growing at 4°C in the presence of naphthalene or salicylate accounted for 65 and 53%, respectively, of the strains isolated. The strains differed in the temperature dependence of their growth rates. It was demonstrated that the type of expression of the Nah⁺ phenotype at low temperatures depended on the combination of host bacterium and plasmid.     

Synergistic temperature and ethanol effect on<Emphasis Type="Italic"> Saccharomyces cerevisiae</Emphasis> dynamic behaviour in ethanol bio-fuel production

The impact of ethanol and temperature on the dynamic behaviour of Saccharomyces cerevisiae in ethanol biofuel production was studied using an isothermal fed-batch process at five different temperatures. Fermentation parameters and kinetics were quantified. The best performances were found at 30 and 33°C around 120 g l^-1 ethanol produced in 30 h with a slight benefit for growth at 30°C and for ethanol production at 33°C. Glycerol formation, enhanced with increasing temperatures, was coupled with growth for all fermentations; whereas, a decoupling phenomenon occurred at 36 and 39°C pointing out a possible role of glycerol in yeast thermal protection.     

Thermohydrogenium kirishiense gen. nov. and sp. nov., a new anaerobic thermophilic bacterium

Six strains of a new anaerobic thermophilic non-sporeforming bacterium were isolated in pure culture from industrial yeast biomass. Cells were rod-shaped (0.4–0.8×1.0–11.0 m), non-motile. They stained gram-negative, but outer membrane was not present. The growth occurred between 45–75 °C, the optimal temperature is 65°. Optimal pH value was 7.0–7.4. The bacterium utilized for growth several sugars, starch and yeast extract. The best source of nitrogen was peptone. The main fermentation products of glucose were ethanol, acetate, H₂ and CO₂. As minor products isopropanol, butanol, butyrate and lactate were found. Glucose was metabolized via the Embden-Meyerhoff pathway. Cytochromes and quinones were not found. DNA-base composition was 33.2–34.0 mol%. The DNA-DNA hybridization and 5S rRNA nucleotide sequences showed distantly related of isolated stains to phenotypical similar bacteria. It was proposed to consider the isolated bacterium as Thermohydrogenium kirishiense gen. nov. and sp. nov.     

Effects of the water-miscible organic solvents on lactoperoxidase purified from creek-water buffalo milk

Water buffalo lactoperoxidase (WBLPO) was purified with Amberlite CG-50 (NH₄ ⁺ form) resin, CM-Sephadex C-50 ion-exchange chromatography, and Sephadex G-100 gel-filtration chromatography from skimmed buffalo milk. The purity of the WBLPO was shown with SDS-PAGE. The R_z(A ₄₁₂/A ₂₈₀) value for the WBLPO was 0.9. The optimum pH for the WBLPO was at 6.0. The K _m value at optimum pH and 25°C was 0.13 mM. The V _max value at optimum pH and 25°C was 5.3 mol/min per ml. The K _i values for methanol, ethanol, dimethyl sulfoxide (DMSO), acetonitrile, isopropanol, tetrahydrofuran (THF), N,N"-dimethylformamide (DMF), and ethylene glycol were 1.087, 0.364, 0.302, 0.459, 0.330, 0.126, 0.093, and 2.125 M, respectively. All the solvents showed competitive inhibition. The I ₅₀ values of methanol, ethanol, dimethyl sulfoxide, acetonitrile, isopropanol, tetrahydrofuran, N,N"-dimethylformamide, and ethylene glycol were 2.910, 0.942, 0.537, 1.320, 0.875, 0.470, 0.405, and 3.920 M, respectively. Ethylene glycol, methanol, acetonitrile, and ethanol have been found to be very promising solvents for performing biocatalytic reactions with LPO in organic media.     

Microbial populations and sludge characteristics in thermophilic aerobic sewage sludge digestion

Summary Estimates of bacterial numbers from raw sewage sludge and sludge treated by thermophilic aerobic digestion were compared with simple indicators of sludge quality and concentrations of potential substrates. Significant differences were found between sludge types for all but one of the variables examined (frequency of dividing cells). During a stable period of digestor operation, the average number of viable obligate thermophiles present in digested sludge (1.63 × 10⁶ ml^–1) was approximately 10²-fold greater than in feed sludge (1.10 × 10⁴ ml^–1). Total numbers of bacteria were slightly greater in digested sludge (3.24 × 10¹⁰ ml^–1) than in feed sludge (2.39 × 10 ml^–10), as were viable counts of bacteria at incubation temperatures of 37°C and 55°C. Significant correlation was found between viable counts of bacteria at 37°C and 55°C for digested sludge, and 65°C and 55°C for feed sludge. The numbers of obligate thermophiles present and the total of bacteria present were related to the temperature and pH of the digested sludge and inversely related to the numbers ofEscherichia coli and coliforms present, which were not detected at temperatures greater than 50°C.     

Conformational studies of alternating copoly(Leu-Lys) and copoly(Leu-Orn) in alcohol-water solvent mixtures

Conformational transitions of alternating copoly(l-leucyl-l-lysine) and copoly(l-leucyl-l-ornithine) in organic solvents and in alcohol-water mixtures were determined by c.d. measurements and the results compared with those from random copoly(Leu^48.3, Lys^51.7). As reported previously^16,17, in salt-free water these alternating copolymers undergo a conformational transition from a disordered to β-structure when the pH is raised or when various salts are added, whereas random copolymers adopt an α-helix conformation under similar conditions. However, both alternating copolymers reveal a tendency to form α-helix in 2,2,2-trifluoroethanol and in alcohol-water mixtures at neutral pH, as does the random copolymer. The alcohol concentration at which the α-helix can be induced is dependent on the kind of alcohol, the α-helix promoting power follows the the series: 2,2,2-trifluoroethanol > isopropanol > ethanol > methanol. In addition, these alternating copolymers in methanol-water mixtures below 50% (by volume) methanol form the β-structure when the pH is raised. On the other hand, above 60% methanol the fraction of α-helix already formed at neutral pH is enhanced at higher pH-values.     

Proteomic analysis of the thermophilic methylotroph Bacillus methanolicus MGA3

Bacillus methanolicus MGA3 is a facultative methylotroph of industrial relevance that is able to grow on methanol as its sole source of carbon and energy. The Gram‐positive bacterium possesses a soluble NAD⁺‐dependent methanol dehydrogenase and assimilates formaldehyde via the ribulose monophosphate (RuMP) cycle. We used label‐free quantitative proteomics to generate reference proteome data for this bacterium and compared the proteome of B. methanolicus MGA3 on two different carbon sources (methanol and mannitol) as well as two different growth temperatures (50°C and 37°C). From a total of approximately 1200 different detected proteins, approximately 1000 of these were used for quantification. While the levels of 213 proteins were significantly different at the two growth temperatures tested, the levels of 109 proteins changed significantly when cells were grown on different carbon sources. The carbon source strongly affected the synthesis of enzymes related to carbon metabolism, and in particular, both dissimilatory and assimilatory RuMP cycle enzyme levels were elevated during growth on methanol compared to mannitol. Our data also indicate that B. methanolicus has a functional tricarboxylic acid cycle, the proteins of which are differentially regulated on mannitol and methanol. Other proteins presumed to be involved in growth on methanol were constitutively expressed under the different growth conditions. All MS data have been deposited in the ProteomeXchange with the identifiers PXD000637 and PXD000638 ( http://proteomecentral.proteomexchange.org/dataset/PXD000637 , http://proteomecentral.proteomexchange.org/dataset/PXD000638 ).     

Production of ethanol at high temperatures in the fermentation of Jerusalem artichoke juice and a simple medium byKluyveromyces marxianus

Summary Temperatures as high as 36°C and 40°C did not negatively affect the ethanol productivity of Jerusalem artichoke (J.a.) juice batch fermentation and the final concentrations of ethanol were close to those produced at lower temperatures. At higher process temperatures (36–40°C), ethanol toxicity inKluyveromyces marxianus was less important during the fermentation of J.a. juice as compared with a simple medium. In simple medium, the heat-sticking of fermentation was observed and the percentage of unfermented sugars steeply increased from 28°C up to 40°C.     

The biodegradation of mixtures of organic solvents by mixed and monocultures of bacteria

Much more information concerning the biodegradation kinetics of mixtures of common industrial chemicals, such as organic solvents, needs to be gathered before wastewater biotreatment process performance can become a matter of design. Here, the biooxidation of a solvent mixture comprizing methanol, acetone, isopropanol, and methylene chloride is examined. The fact that the enrichment culture obtained comprized only two solvent-utilizing strains, together with only minor percentages of nonsolvent utilizing satellite strains, was contrary to the theory of microbial competition. In addition, the complex relationship between the two solvent-utilizing strains indicates that further work is necessary on the pathways involved in isopropanol and acetone biooxidation and on the effects of operating conditions on the fluxes along such pathways.     

Production of butanol by Clostridium puniceum in batch and continuous culture

Summary The pink-pigmented, amylolytic and pectinolytic bacterium Clostridium puniceum in anaerobic batch culture at pH 5.5 and 25–30°C produced butan-1-ol as the major product of fermentation of glucose or starch. The alcohol was formed throughout the exponential phase of growth and surprisingly little acetone was simultaneously produced. Furthermore, acetic and butyric acids were only accumulated in low concentrations, and under optimal conditions were completely re-utilised before the fermentation ceased. Thus, in a minimal medium containing 4% w/v glucose as sole source of carbon and energy, after 65 h at 25°C, pH 5.5 all of the glucose had been consumed to yield (g product/100 g glucose utilised) butanol 32, acetone 3 and ethanol 2. Butanol was again the major product of glucose fermentation during phosphate-limited chemostat culture wherein, although the organism eventually lost its capacity to sporulate and to synthesize granulose, production of butanol continued for at least 100 volume changes. Under no growth condition was the organism capable of producing more than 13.3 g l^-1 of butanol. At pH 5.5, growth on pectin was slow and yielded a markedly lesser biomass concentration than when growth was on glucose or starch; acetic acid was the major fermentation product with lower concentrations of methanol, acetone, butanol and butyric acid. At pH 7, growth on all substrates produced virtually no solvents but high concentrations of both acetic and butyric acids.     

Temperature Effect on Carbachol-Induced Depression of Spontaneous Quantal Transmitter Release in Frog Neuromuscular Junction

The effects of carbachol (CCh) on the frequency (f) of the miniature endplate potentials were tested at temperatures between 5 and 30°C. Higher CCh concentrations, 1 × 10^–5 and 5 × 10^–6 M, reduced the f to 60% and the temperature dependence was negligible. However, an inverse temperature dependence was found when low concentrations 3 × 10^–7 and 6 × 10^–7 M were applied. The depression of f was 40–50% in 5–10°C but only 10–20% of the control in the 25 and 30°C. During application of CCh, the new steady of f was reached at temperatures between 5 and 30°C within 17–20 min (Q₁₀ = 1.07). Much greater temperature dependence of recovery was observed during washing out CCh (Q₁₀ = 1.6). The temperature-independence of the steady state effects of CCh, good agreement with Langmuir adsorption-desorption theory and non-steady kinetics indicate that physical rather than receptor-mediated events are responsible for the depression of f.     

Thermoanaerobium lactoethylicum spec. nov. a new anaerobic bacterium from a hot spring of Kamchatka

A new anaerobic thermophilic Gram-positive, nonsporeforming bacterium strain ZE-1 was isolated from a hot spring of Kamchatka (USSR). The cells are rod-shaped, (0.5–0.8 · 2.0–20 m), non-motile. The bacterium can grow between 42 and 75°C; the optimal temperature is 65°C. The growth is possible between pH values 5.0 and 8.5; optimal pH is 7.0. The cultures grow on the media containing peptone, yeast extract, or casein hydrolysate as nitrogen sources in the presence of glucose or some other sugars, mannitol or starch. The main fermentation products of glucose are ethanol, acetate, lactate, H₂, CO₂; byproducts are propionic, butyric and isovaleric acids. Glucose is metabolized via Embden-Meyerhoff-Parnas pathway. Molecular hydrogen does not inhibit growth. The bacterium does not reduce aceton to isopropanol, but is able to form H₂S from elemental sulfur. The bacterium contains a soluble hydrogenase. This enzyme catalyzes both evolution and uptake of H₂ and is active in the presence of methyl viologen. The DNA-base composition is 34.6 mol%; the genome size 2.08x10⁹ D. The name proposed for the isolated bacterium strain ZE-1 is Thermoanaerobium lactoethylicum spec. nov.     

Pervaporation performance of a composite bacterial cellulose membrane: dehydration of binary aqueous–organic mixtures

Summary Acetobacter xylinum (Gluconacetobacter xylinus) is a bacterium that produces extracellular cellulose under static culture conditions. The highly reticulated cellulose matrix along with the entrapped cellulose-forming bacteria is commonly referred to as a pellicle. The processed bacterial cellulose membrane/film was modified into a composite bacterial cellulose membrane (CBCM) for pervaporation separation of aqueous–organic mixtures. The CBCM was prepared by coating with alginate or alginate+polyvinylpyrrolidone and cross-linking with glutaraldehyde. The pervaporation performance was determined using aqueous–organic mixtures such as, 1:1 (v/v) water–ethanol, water–isopropanol and water–acetone. The pervaporation performance of the CBCM was more effective for zeotropic mixtures (water–acetone) in comparison to the investigated azeotropic mixtures (water–ethanol and water–isopropanol). The selectivity of CBCM was found to be 4.8, 8.8, 19.8 for water–ethanol, water–isopropanol and water–acetone mixtures, respectively. The permeation flux for the water–acetone mixture was found to be 235 ml/m²/h. The present investigation demonstrated that the CBCM could be employed to concentrate azeotropic as well as zeotrope forming binary mixtures by preferential pervaporation of water, with low energy requirements in contrast to the established method of distillation. In addition, the effects of feed composition, operating temperature, membrane thickness, and method of CBCM preparation on pervaporation performance have been evaluated. Investigations with the CBCM revealed that 94.5% ethanol, 98% acetone and 98.5% isopropanol concentrations could be attained from the initial 50% aqueous mixtures of these chemicals by way of pervaporation. In the case of the isopropanol–water mixture the resolving property of the membrane was more evident as the concentration arrived at was 98.5%, in contrast to other binary mixtures. The surface characteristics of the CBCM were revealed by scanning electron microscopy. In view of its properties the CBCM can be useful for pervaporation separation of these chemicals at moderate temperatures and pressure. The CBCM could be employed in the downstream processing of heat-labile and flavor-imparting volatile molecules in the field of food biotechnology and fabrication of membrane bioreactors for on-line product purification. Further studies are under progress to use the membrane for the immobilization of food processing enzymes.     

Variability in survival of Pectinatus cerevisiiphilus, strictly anaerobic bacteria, under different oxygen conditions

Survival of Pectinatus cerevisiiphilus DSM 20466 in pure culture at variable temperatures under different oxygen concentrations was measured. Survival of P. cerevisiiphilus in co-culture with Saccharomyces cerevisiae under both saturated oxygen and brewing conditions was also studied. The survival of strictly anaerobic bacteria to oxygen seems to follow the classical laws of heat resistance. The D(oxy) values of P. cerevisiiphilus , calculated as a function of oxygen level, shows that the oxygen level is important for the survival duration of the bacteria. The temperature greatly influences the oxygen resistance of P. cerevisiiphilus, which increases when the temperature decreases. P. cerevisiiphilus resists better in co-culture than in pure culture under saturated oxygen conditions. Therefore, the oxygenation of the wort does not totally eliminate the risk of beer contamination by this bacterium. Under brewing conditions in co-culture at 8 degrees C, P. cerevisiiphilus grows slowly to reach a final cell concentration up to 10(6) cells/mL in beer, which is undrinkable. Pectinatus is a strictly anaerobic bacterium; however, it is resistant under certain oxygen conditions of incubation. This resistance is considerably higher in the presence of Saccharomyces cerevisiae .     

Physiological characteristics of four methylotrophic bacteria and their potential use in single-cell protein production

Summary Four methylotrophic bacteria, isolated at the Kuwait Institute for Scientific Research, were able to grow on methanol as the only carbon source at a maximum temperature of 44°C. An optimized medium composition was obtained through intensive chemostat studies varying both macro- and micro-element concentrations. Various batch and chemostat experiments were carried out at different pH, temperature, dilution rate and methanol concentrations. The results showed optimum pH around 6.8, at temperatures of 37 to 40°C, dilution rate 0.2–0.3 h^–1 and methanol was found to be inhibitory at concentrations above 20 g l^–1. The performance of all four bacteria under chemostat conditions was similar. Chemostat fermentation experiments using the optimized medium at 40°C, pH 6.8, dilution 0.2 h^–1 and 10 g methanol/l in the feed gave a biomass yield coefficient of 0.42–0.44 g/g methanol, 78–79% crude protein content, 58–62% total amino acid content and 10–11.5% nucleic acid content. In conclusion all four methylotrophic strains has good potential for use in the production of single-cell protein.

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Caractéristiques physiologiques de quatre bactéries méthylotrophes et leur emploi potentiel dans la production de protéine uni-celluliare

Résumé Quatre bactéries méthylotrophes, isolées à l'Institut pour la Recherche Scientifique du Kuweit, se sont révélées capables de croître sur méthanol comme seule source de carbone à une température maximum de 44°C. Des études intensives en chémostat de variation des concentrations tant en macro-qu'en micro-éléments, ont permis d'obtenir une composition optimum du milieu. Diverses expériences en milieu non renouvelé et en chémostat ont été effectuées à différents pH, températures, taux de dilution et concentration en méthanol. Les résultats ont montré un optimum de pH vers 6.8, de température entre 37 et 40°C, de taux de dilution de 0.2 à 0.3 h^–1. Le méthanol s'est révélé inhibiteur aux concentrations supérieures à 20 g l^–1. La performance des quatres bactéries dans les conditions du chémostat se sont révélées très semblables. Les expériences de fermentátion en chémostat, utilisant le milieu optimum à 40°C, pH 6.8, taux de dilution de 0.2 h^–1 et à 10 g de méthanol par litre dans l'alimentation ont produit un coefficient de rendement en biomasse de 0.42 à 0.44 g de cellules par g de méthanol contenant de 78 à 79% de protéines, de 58 à 62% d'acides aminés totaux et de 10 à 11.5% d'acides nucléiques. En conclusion, les quatre bactéries méthylotrophes présentent une bonne potentialité pour être utilisées dans la production de protéine uni-cellulaire.

     

Anaerobic,alkaliphilic, saccharolytic bacterium <Emphasis Type="Italic">Alkalibacter saccharofermentans</Emphasis> gen. nov., sp. nov. from a soda lake in the Transbaikal region of Russia

Three strains of new obligately anaerobic alkaliphilic bacteria have been isolated as a saccharolytic component from the cellulolytic community of alkaline Lake Nizhnee Beloe (Transbaikal region, Russia), a lake with low salt concentration. DNA analysis of these strains showed an interspecies level of DNA similarity of 96–100%. Strain Z-79820 was selected for further investigations. Cells were Gram-positive, asporogenous, nonmotile short rods with pointed ends. The strain was a true alkaliphile: growth occurred from pH 7.2 to 10.2 with the optimum at pH 9.0. Strain Z-79820 was halotolerant and could grow in medium with up to 10% (w/v) NaCl, with the optimum between 0 and 4% NaCl. The new isolate obligately depended on Na⁺ ions in the form of carbonates or chlorides. Total Na⁺ content needed for optimal growth was 0.46 M Na⁺, with a wide range from 0.023–0.9 M Na⁺ at which growth also occurred. The isolate was a mesophile and grew at temperatures from 6 to 50°C (slow growth at 6 and 15°C) with an optimum at 35°C. The organotrophic organism fermented ribose, xylose, glucose, mannose, fructose, sucrose, mannitol, and peptone. The products of glucose fermentation were acetate, ethanol, formate, H₂, and CO₂. Yeast extract was required for some anabolic needs. The DNA G+C content of the type strain Z-79820 was 42.1 mol%. The new bacterium fell into the 16S rRNA gene cluster XV of the Gram-positive bacteria with low G+C content, where it formed an individual branch. Based on its growth characteristics and genotype traits, we propose the new genus and species named Alkalibacter saccharofermentans with the type strain Z-79820 (=DSM14828), Uniqem-218 (Institute Microbiology, RAS; ).     

Ethanol production from glucose byClostridium thermosaccharolyticum strains: Effect of pH and temperature

Summary The fermentation of glucose byClostridium thermosaccharolyticum strains IMG 2811^T, 6544 and 6564 was studied in batch culture in a complex medium at different temperatures in defined and free-floating pH conditions. All the strains ferment 5 g glucose.l^–1 completely. The yield of the fermentation products turned out to be independent of the incubation temperature for strain IMG 2811^T. Strain IMG 6544 produced at 60°C significantly more ethanol and less acetic acid, butyric acid, hydrogen gas and biomass than at lower temperatures. With strain IMG 6564, the opposite effect occurred: ethanol appeared to be the main fermentation product at 45°C; at 60°C less ethanol and more acetic acid, butyric acid and hydrogen gas was formed.Experiments, carried out with strain IMG 6564, at defined pH conditions (between 5.5 and 7) and different temperatures (45, 55 and 60°C) revealed no effect of the incubation temperature, but an important effect of the pH on the product formation. At pH 7, ethanol was the main fermentation product while minor amounts of hydrogen gas, acetic and butyric acid were produced. Lowering the pH gradually to 5.5 resulted in a decrease of ethanol and an increase of biomass, hydrogen gas, acetic, butyric and lactic acids. At pH higher than 7 no growth occurred. Similar conclusions could be drawn for strains IMG 2811^T and 6544.     

Downstream processing and purification of eicosapentaenoic (20:5n-3) and arachidonic acids (20:4n-6) from the microalga Porphyridium cruentum

Eicosapentaenoic acid (FPA, 20:5n-3) and arachidonic acid (AA, 20:4n-3)were obtained from the microalga Porphyridium cruentum by a three-stepprocess: fatty acid extraction by direct saponification of biomass,polyunsaturated fatty acid (PUFA) concentration by urea inclusion complexingand EPA isolation by high-performance liquid chromatography (HPLC). Twosolvents were tested for direct saponification of lipids in biomass. Themost efficient solvent, ethanol (96% v/v), extracted 75% ofthe fatty acids. PUFAs concentration by urea inclusion employed a urea/fattyacid ratio of 4:1 wt/wt at the crystallization temperatures of 4°C and28°C. Concentration factors were similar at both temperatures, but theEPA and AA recoveries were higher at 28°C (67.7% and 61.8%for the two acids, respectively). EPA and AA were purified from this PUFAconcentrate using analytical scale HPLC and the best results of thisseparation were scaled up to preparative level (4.7 i. d. × 30 cmcompression radial cartridge). A 94.3% pure EPA fraction and a81.4% pure AA fraction were obtained. Suitability of severalmicroalgae (Porphyridium cruentum, Phaeodactylum tricornutum and Isochrysisgalbana) and cod liver oil as sources of highly pure PUFAs, mainly EPA, wascompared.     

[1-14C] Acetate assimilation by obligate methylotrophs,Pseudomonas methanica and Methylosinus trichosporium

The oxidation of one carbon compounds (methane, methanol, formaldehyde, formate) and primary alcohols (ethanol, propanol, butanol) supported the assimilation of [1-¹⁴C]acetate by cell suspensions of type I obligate methylotroph; Pseudomonas methanica, Texas strain, and type II obligate methylotroph, Methylosinus trichosporium, strain PG. The amount of oxygen consumed and substrate oxidized correlated with the amount of [1-¹⁴C]acetate assimilated during oxidation of C-1 compounds and primary alcohols.Oxidation of methanol, formaldehyde, and primary alcohols in extracts of Pseudomonas methanica, Texas strain, and Methylosinus trichosporium, strain PG, was catalyzed by a phenazine methosulfate linked, ammonium ion dependent methanol dehydrogenase. The oxidation of aldehydes was catalyzed by a phenazine methosulfate linked, ammonium ion independent aldehyde dehydrogenase. Formate was oxidized by a NAD⁺ linked formate dehydrogenase.Deceased.This work was supported by Grant GB 8173 from the National Science Foundation and by a grant from the Robert A. Welch Foundation.