Desulfobacter

Widdel F (1987) New types of acetate-oxidizing, sulfate-reducing Desulfobacter species, D. hydrogenophilus sp. nov., D. latus sp. nov., and D. curvatus sp. nov. Arch Microbiol 148 286-291. 

Following the calculations in Section 18.5, we take a rate constant k+ for sulfate reduction of 10-9 mol mg-1 s-1, a half-saturation constant for acetate of 70 p, molal, and a growth yield of 4300 mg mol-1 from a study of the kinetics of Desulfobacter postgatei by Ingvorsen el al. (1984). We set a value for KA, the half-saturation constant for sulfate, of 200 p molal, as suggested by Ingvorsen el al. (1984) and Pallud and Van Cappellen (2006). 

Ingvorsen, K., A. J. B. Zehnder and B.B. Jprgensen, 1984, Kinetics of sulfate and acetate uptake by Desulfobacter postgatei. Applied and Environmental Microbiology 47,403 -08. 

Figure 7.9 Depth variation in microbial community structure in the Upper Marsh trench section (Profile A) indicated by changing abundances of (a) monoenoics, (b) normal saturates, (c) ratio of OHFA to PLFA, (d) 10Me16 0 (biomarker for Desulfobacter, and (e) i17 1w7c (biomarker for Desulfovibrio).

Figure 7.16 Indicators of community structure and environmental stress in profile 93CB (a) abundance of monoenoics, (b) abundance of branched saturates, (c) OHFA/PLFA ratio, (d) the biomarker for Desulfobacter (10Me16 0), (e) the biomarker for Desulfovibrio (i17 1w7c), and (fl the ratio of cy19 0/18 Iw7c.

Oxidation may take place by a modified tricarboxylic acid cycle in which the production of C02 is coupled to the synthesis of NADPH and reduced ferredoxin, and the dehydrogenation of succinate to fumarate is coupled to the synthesis of reduced menaquinone. This pathway is used for example by D. acetoxidans and in modified form by Desulfobacter postgatei. 

Gorny, N. and B. Schink. 1994b. Anaerobic degradation of catechol by Desulfobacte-rium sp. strain cat2 proceeds via carboxylation to protocatechuate. Appl. Environ. Microbiol. 60 3396-3400. 

Sulphate reduction becomes important when nitrate is depleted its products are carbon dioxide, water and hydrogen sulphide (Box 3.10). Sulphate reducers (e.g. Desulfo vibrio, Desuifolomaculum, Desulfobacter,... 

Internally branched acids occur naturally, such as the 10-methyl (numbering from the acid-group end) isomers of 16 0 and 18 0 found in fungi and bacteria. For example, 10-methyl 16 0 (Fig. 5.1) is characteristic of Desulfobacter (Taylor Parkes 1983). There are also cycloalkyl acids, such as 17 0 and 19 0 cyclopropyl moieties. Cyclopropyl acids are more common in eubacteria than other organisms, but the position of the cyclopropyl group is important. Out of the more commonly occurring cw-11,12 and as-9,10 isomers of 19 0 and the as-9,10 isomer of 17 0, only the as-11,12 iso-... 

Taylor J., Parkes R.J. (1983) The cellular fatty acids of the sulphate-reducing bacteria, Desulfobacter sp., Desulfobulbus sp. and Desulfovibrio desulfuricans.J. Gen. Microbiol. 129, 3303—9. 

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