The Isolation and Characteristics of an Organism Oxidizing Thiocyanate

Happold, F. C.; Johnstone, Keith; Rogers, H. J.; Youatt, Jean

doi:10.1099/00221287-10-2-261

Cited by 61 publications

(21 citation statements)

References 5 publications

(6 reference statements)

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“…Among the neutrophilic sulfur-oxidizing bacteria, the ability to grow with thiocyanate as an electron donor for energy generation and CO 2 fixation is limited to a few strains of T. thioparus (7,12,13,20,32,33,47) and Thiobacillus denitrificans (7). The ability to utilize thiocyanate as an electron donor has recently been claimed for a newly described Paracoccus species, Paracoccus thiocyanatus (18), but it is difficult to analyze the evidence because no actual data for growth and oxidation kinetics were provided in the paper.…”

Section: Thiocyanate (N'cosmentioning

confidence: 99%

Microbial Thiocyanate Utilization under Highly Alkaline Conditions

Sorokin¹,

Tourova²,

Lysenko³

et al. 2001

Appl Environ Microbiol

112

104

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Three kinds of alkaliphilic bacteria able to utilize thiocyanate (CNS ؊ ) at pH 10 were found in highly alkaline soda lake sediments and soda soils. The first group included obligate heterotrophs that utilized thiocyanate as a nitrogen source while growing at pH 10 with acetate as carbon and energy sources. Most of the heterotrophic strains were able to oxidize sulfide and thiosulfate to tetrathionate. The second group included obligately autotrophic sulfur-oxidizing alkaliphiles which utilized thiocyanate nitrogen during growth with thiosulfate as the energy source. Genetic analysis demonstrated that both the heterotrophic and autotrophic alkaliphiles that utilized thiocyanate as a nitrogen source were related to the previously described sulfur-oxidizing alkaliphiles belonging to the gamma subdivision of the division Proteobacteria (the Halomonas group for the heterotrophs and the genus Thioalkalivibrio for autotrophs). The third group included obligately autotrophic sulfur-oxidizing alkaliphilic bacteria able to utilize thiocyanate as a sole source of energy. These bacteria could be enriched on mineral medium with thiocyanate at pH 10. Growth with thiocyanate was usually much slower than growth with thiosulfate, although the biomass yield on thiocyanate was higher. Of the four strains isolated, the three vibrio-shaped strains were genetically closely related to the previously described sulfur-oxidizing alkaliphiles belonging to the genus Thioalkalivibrio. The rod-shaped isolate differed from the other isolates by its ability to accumulate large amounts of elemental sulfur inside its cells and by its ability to oxidize carbon disulfide. Despite its low DNA homology with and substantial phenotypic differences from the vibrio-shaped strains, this isolate also belonged to the genus Thioalkalivibrio according to a phylogenetic analysis. The heterotrophic and autotrophic alkaliphiles that grew with thiocyanate as an N source possessed a relatively high level of cyanase activity which converted cyanate (CNO ؊ ) to ammonia and CO 2 . On the other hand, cyanase activity either was absent or was present at very low levels in the autotrophic strains grown on thiocyanate as the sole energy and N source. As a result, large amounts of cyanate were found to accumulate in the media during utilization of thiocyanate at pH 10 in batch and thiocyanate-limited continuous cultures. This is a first direct proof of a "cyanate pathway" in pure cultures of thiocyanate-degrading bacteria. Since it is relatively stable under alkaline conditions, cyanate is likely to play a role as an N buffer that keeps the alkaliphilic bacteria safe from inhibition by free ammonia, which otherwise would reach toxic levels during dissimilatory degradation of thiocyanate.

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Section: Thiocyanate (N'cosmentioning

confidence: 99%

Microbial Thiocyanate Utilization under Highly Alkaline Conditions

Sorokin¹,

Tourova²,

Lysenko³

et al. 2001

Appl Environ Microbiol

112

104

View full text Add to dashboard Cite

show abstract

“…The ability to grow with thiocyanate as an electron donor for energy generation and CO 2 fixation is restricted to a few strains of neutrophilic thiobacilli (De Kruyff et al, 1957;Happold et al, 1954Happold et al, , 1958Katayama & Kuraishi, 1978;Smith & Kelly, 1988;Youatt, 1954). Recently, we described several new thiocyanate-oxidizing bacteria capable of chemolithoautotrophic growth with thiocyanate at high pH and salt concentration (Sorokin et al, 2001a).…”

Section: Introductionmentioning

confidence: 99%

Anaerobic growth of the haloalkaliphilic denitrifying sulfur-oxidizing bacterium Thialkalivibrio thiocyanodenitrificans sp. nov. with thiocyanate

Tourova²,

et al. 2004

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Two strains of obligate chemolithoautotrophic sulfur-oxidizing bacteria were isolated from soda-lake sediments by enrichment culture with thiocyanate and nitrate at pH 9?9. The isolates were capable of growth with thiocyanate or thiosulfate as electron donor, either aerobically or anaerobically, and with nitrate or nitrite as electron acceptor. Cyanate was identified as an intermediate of thiocyanate oxidation, while sulfate, ammonia and dinitrogen gas were the final products. The anaerobic growth on thiocyanate plus nitrate was much slower (m max =0?006 h "1 ) than on thiosulfate plus nitrate (m max =0?02 h "1 ), while growth yields were similar (4?8 and 5?1 g protein mol "1 , respectively). On the basis of their phenotypic and genetic properties, strains ARhD 1 T and ARhD 2 are described as a novel species of the genus Thialkalivibrio, with the highest similarity to Thialkalivibrio denitrificans. The name Thialkalivibrio thiocyanodenitrificans sp. nov. is proposed for this novel species.

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“…Several studies have previously reported on the heterotrophic (Betts et al 1979;Boucabeille et al 1994) and autotrophic (Happold et al 1954;Katayama and Kuraishi 1978 1 ;Mudder and Whitlock 1984;Katayama et al 1992;Whitlock 1992;Hung and Pavlostathis 1997) (Neufeld et al 1981;Hung and Pavlostathis 1999). The work by Neufeld et al (1981) made use of fed-batch reactors, while that of Hung and Pavlostathis (1999) made use of batch reactors.…”

Section: Introductionmentioning

confidence: 99%

Empirical model for the autotrophic biodegradation of thiocyanate in an activated sludge reactor

Plessis

Barnard

Muhlbauer

et al. 2001

Lett Appl Microbiol

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Aims: The aim of this investigation was to develop an empirical model for the autotrophic biodegradation of thiocyanate using an activated sludge reactor. Methods and Results: The methods used for this purpose included the use of a laboratory scale activated sludge reactor unit using thiocyante feed concentrations from 200 to 550 mg l )1 . Reactor ef¯uent concentrations of <1 mg l )1 thiocyanate were consistently achieved for the entire duration of the investigation at a hydraulic retention time of 8 h, solids (biomass) retention of 18 h and biomass (dry weight) concentrations ranging from 2 to 4 g l )1 . A biomass speci®c degradation rate factor was used to relate thiocyanate degradation in the reactor to the prevailing biomass and thiocyanate feed concentrations. A maximum biomass speci®c degradation rate of 16 mg )1 g )1 h )1 (mg thiocyanate consumed per gram biomass per hour) was achieved at a thiocyanate feed concentration of 550 mg l )1 . The overall yield coef®cient was found to be 0á086 (biomass dry weight produced per mass of thiocyanate consumed). Conclusions: Using the results generated by this investigation, an empirical model was developed, based on thiocyanate feed concentration and reactor biomass concentration, to calculate the required absolute hydraulic retention time at which a single-stage continuously stirred tank activated sludge reactor could be operated in order to achieve an ef¯uent concentration of <1 mg l )1 . The use of an empirical model rather than a mechanistic-based kinetic model was proposed due to the low prevailing thiocyanate concentrations in the reactor. Signi®cance and Impact of the Study: These results represent the ®rst empirical model, based on a comprehensive data set, that could be used for the design of thiocyanate-degrading activated sludge systems.

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The Isolation and Characteristics of an Organism Oxidizing Thiocyanate

Cited by 61 publications

References 5 publications

Microbial Thiocyanate Utilization under Highly Alkaline Conditions

Microbial Thiocyanate Utilization under Highly Alkaline Conditions

Anaerobic growth of the haloalkaliphilic denitrifying sulfur-oxidizing bacterium Thialkalivibrio thiocyanodenitrificans sp. nov. with thiocyanate

Empirical model for the autotrophic biodegradation of thiocyanate in an activated sludge reactor

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