Hydrogenomonas

Fang and Burris (63) isolated a c-type cytochrome from the cells of Hydrogenomonas eutropha. Type c cytochromes have been isolated from the cells of a number of other bacterial species (64) and a three dimensional model has been proposed for the cytochrome C551 of Pseudomonas aeru-... 

Colorless sulfur bact. (Thiobaciiius, Beggiatoa) Nitrif/ing bact. (Thiobaciiius, Nitro- bacter) Hydrogen bact. (Hydrogenomonas)... 

In an in vitro fermentation study, rumen microorganisms metabolized both isomers of [ C]DDT o,p- and p,p-) to the corresponding DDD isomers at a rate of 12%/h. With p,//-DDT, 11% of the C detected was an unidentified polar product associated with microbial and substrate residues (Fries et al., 1969). In another in vitro study, extracts of Hydrogenomonas sp. cultures degraded DDT to DDD, l-chloro-2,2-bis(/5-chlorophenyl)ethane (DDMS), DBF, and several other products under anaerobic conditions. Under aerobic conditions containing whole cells, one of the rings is cleaved and p-chlorophenylacetic acid is formed (Pfaender and Alexander, 1972). 

The hydrogen-oxidizing bacteria. Species from several genera including Hydrogenomonas, Pseudomonas, and Alcaligenes oxidize H2 with oxygen ... 

Hydrogenomonas sp. Kaltwasser and Schlegel, 1959 Kaltwasser, 1962 Schlegel, 1951 Schlegel and Kaltwasser, 1961... 

In certain aerobic organisms, such as hydrogenomonas, H2 and O2 are caused to react (but not directly) according to the Knallgas reaction ... 

Most hydrogen bacteria are rodlike and are known under the generic name Hydrogenomonas (Fig. 1). Several strains were given specific... 

Fig. 1. Hydrogenomonas strain H16 (Wilde, 1961) which is similar to Hydrogenomonas eutropha. Electron micrograph...

Fig. 2. Growth of Hydrogenomonas H16 at different oxygoi concentrations starting with different cell densities. 31 mineral meHinm pH 6.8 in 61 flasks magMtic stirring 650 rpm gas atmosphere 5, 10 or 30% oxygen+10% carbon dioxide+molecular hydrogen ad 100% Turbidity measurements at 436 nm (from Schlegel et al 1961)...

Hydrogen bacteria are facultative chemoautotrophs they grow as well or at an even higher rate under heterotrophic conditions. Fructose is the only carbohydrate which many strains such as Hydrogenomonas eutropha and strain H16 can utilize as a substrate. Most strains are able to grow with organic adds and amino acids. Some strains are also able to decompose aromatic compounds, purines, and pyrimidines. 

Fig. 3. Gascontainer system for cultivating Hydrogenomonas under a gas atmosphere of hydrogen, oxygen and carbon dioxide. / gas reservoir 2 culture vessel 3 sampling device 4 magnetic stirrer...

As already mentioned, suspensions of high densities consume large volumes of gas. The normal gas consumption rate of Hydrogenomonas... 

Fig. 6. Chemostat for continuous cultivation of Hydrogenomonas. 1 medium reservoir 2 pump 3 constant-level vessel 4 timer 5 valve 6 thermal trap 7 collecting vessel 8 flow meters 9 Waldhof cylinder...

Table 1. Comparison of the growth of Hydrogenomonas H16 in the chemostat with limiting concentrations of hydrogen or oxygen (from Schuster and Schlegel, 1967J...

Fig. 8. The influence of the hydrogen concentration on the dissolved oxygen concentration measured in a suspension of Hydrogenomonas H16 stirred under the conditions, outlined in Fig. 7, at four different oxygen concentrations in the gas phase...

Fig. 9. Apparatus for growing Hydrogenomonas H16 ia batch culture with internal gas supply (electrolysis of the culture medium by platinum electrodes). Carbon dioxide containing nitrogen is blown through the air space of the vessel. Auxiliaries are shown. 1 flow meters 2 solution of iron salts 3 pump 4 timer 5 sampling device 6 temperature control 7 polarity switch 8 rectifier 9 electrodes...

Table 2. Amino acid composition of Hydrogenomonas eutropha, Peudomonas saccharophila and casein (tcdcen from Calloway and Kumar, i969) values expressed as g 16 g of nitrogen...

Fig. 11. Accumulation of poly- -hydroxybutyric acid in the cells of Hydrogenomonas H 16. The cells had been grown exponentially (a) and were then incubated for 1 (b) and 24 hrs. (c) in the presence of 0.1 % acetate as a carbon source in the absence of a nitrogen source (Electron micrographs of ultrathin sections taken by P. Hillmer and F. Amelunxen)... 

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