Anaerobic Production of Thiobacillus denitrificans for the Enzyme Rhodanese

Abstract

production of Thiobacillus denitrificans for the enzyme rhodanese. Appl. Microbiol. 14:998-1003. 1966.-A method for the anaerobic growth of 7hiobacillus denitrificans in a 140-liter (total capacity) stainless-steel culture vessel is described. As a result of controlling the pH value of cultures, and of ensuring that certain essential nutrients were in excess, cell yields approaching 700 mg (dry weight) per liter were obtained. These were over threefold higher than the best yields hitherto reported. The average rhodanese content of the cells from four cultures was 176,000 units per gram (dry weight). Adenosine-5'-phosphosulfate reductase (average content, 238 units per gram dry weight) and adenylate kinase (average content, 15,300 units per gram, dry weight) were also present. Earlier methods of cultivating Thiobacillus denitrificans under anaerobic conditions were based on use of the medium of Baalsrud and Baalsrud (2), which contains: NH4Cl, 0.05%; 998 Vol. 14, No. 6

Thiosulfate, polythionates and elemental sulfur assimilation and reduction in the bacterial world

“…Tlfiosulfate reductase activity is found in numerous microorganisms [54,[66][67][68][69][70][71][72][73][74][75][76][77]. Two different classes of enzymes have been described.…”

“…Rhodanese is a constitutive enzyme and its specific activity is enhanced only 2-3 times by varying culture conditions: e.g. in T. denitrificans a higher medium pH, increase in thiosulfate concentration [54], or addition of cyanide [35]; in Tcp. roseopersicina during anaerobic autotrophic growth [53]; in Neisseria ( N.) gonorrhoeae, grown with thiosulfate or sulfur flower (in place of cysteine) [6].…”

Microorganisms and cyanide.

“…Lang showed (83) that rhodanese catalyzes the formation of thiocyanate and sulfite from thiosulfate and cyanide: S2032-+ CN-SO32-+ SCN-Rhodanese has since been shown to catalyze a range of bacteria. The frequent observations of rhodanese in Thiobacillus species (18,31,32,90,100,145,173,175), in photosynthetic bacteria (159,198), and in Desulfphomaculatum (11) suggest that, in these organisms at least, it has a role in sulfur metabolism rather than one as a cyanide detoxifying agent. Rhodanese has also been found in several non-photosynthetic heterotrophic microorganisms (7,8,83,149,180,181).…”