Utilization of organic compounds as the sole source of nitrogen by Thiobacillus thiooxidans

1988 ◽  
Vol 150 (1) ◽  
pp. 85-88 ◽  
Author(s):  
Norbert Metzdorf ◽  
Heinrich Kaltwasser
Keyword(s):  
Organic Compounds ◽  
Sole Source ◽  
Thiobacillus Thiooxidans

scholarly journals Estimation of the Yield Coefficient ofPseudomonas sp. Strain DP-4 with a Low Substrate (2,4-Dichlorophenol [DCP]) Concentration in a Mineral Medium from Which Uncharacterized Organic Compounds Were Eliminated by a Non-DCP-Degrading Organism

2000 ◽  
Vol 66 (2) ◽  
pp. 566-570 ◽  
Author(s):  
Mitsunori Tarao ◽  
Masayuki Seto
Keyword(s):  
Mixed Culture ◽  
Organic Compounds ◽  
Pure Culture ◽  
Mineral Salt Medium ◽  
Sole Source ◽  
Final Concentration ◽  
Yield Coefficient ◽  
Salt Medium ◽  
Initial Concentration ◽  
Low Concentrations

ABSTRACT The yield coefficient (YC) of Pseudomonas sp. strain DP-4, a 2,4-dichlorophenol (DCP)-degrading organism, was estimated from the number of CFU produced at the expense of 1 unit amount of DCP at low concentrations. At a low concentration of DCP, the YC can be overestimated in pure culture, because DP-4 assimilated not only DCP but also uncharacterized organic compounds contaminating a mineral salt medium. The concentration of these uncharacterized organic compounds was nutritionally equivalent to 0.7 μg of DCP-C ml−1. A mixed culture with non-DCP-degrading organisms resulted in elimination of ca. 99.9% of the uncharacterized organic compounds, and then DP-4 assimilated only DCP as a substrate. In a mixed culture, DP-4 degraded an initial concentration of 0.1 to 10 μg of C ml of DCP−1 and the number of CFU of DP-4 increased. In the mixed culture, DCP at an initial concentration of 0.07 μg of C ml−1 was degraded. However, the number of CFU of DP-4 did not increase. DCP at an extremely low initial concentration of 0.01 μg of C ml−1 was not degraded in mixed culture even by a high density, 105 CFU ml−1, of DP-4. When glucose was added to this mixed culture to a final concentration of 1 μg of C ml−1, the initial concentration of 0.01 μg of C ml of DCP−1 was degraded. These results suggested that DP-4 required cosubstrates to degrade DCP at an extremely low initial concentration of 0.01 μg of C ml−1. The YCs of DP-4 at the expense of DCP alone decreased discontinuously with the decrease of the initial concentration of DCP, i.e., 1.5, 0.19, or 0 CFU per pg of DCP-C when 0.7 to 10, 0.1 to 0.5, or 0.07 μg of C ml of DCP−1 was degraded, respectively. In this study, we developed a new method to eliminate uncharacterized organic compounds, and we estimated the YC of DP-4 at the expense of DCP as a sole source of carbon.

scholarly journals Trimethylamine metabolism in obligate and facultative methylotrophs

1973 ◽  
Vol 132 (1) ◽  
pp. 101-112 ◽  
Author(s):  
J. Colby ◽  
L. J. Zatman
Keyword(s):  
Organic Compounds ◽  
Pure Culture ◽  
Sole Source ◽  
The Other ◽  
Bacterial Isolates ◽  
Hydrogen Acceptor ◽  
Trimethylamine Dehydrogenase ◽  
Phenazine Methosulphate

1. Twelve bacterial isolates that grow with trimethylamine as sole source of carbon and energy were obtained in pure culture. All the isolates grow on methylamine, dimethylamine and trimethylamine. One isolate, bacterium 4B6, grows only on these methylamines whereas another isolate, bacterium C2A1, also grows on methanol but neither grows on methane; these two organisms are obligate methylotrophs. The other ten isolates grow on a variety of Ci and other organic compounds and are therefore facultative methylotrophs. 2. Washed suspensions of the obligate methylotrophs bacteria 4B6 and C2A1, and of the facultative methylotrophs bacterium 5B1 and Pseudomonas 3A2, all grown on trimethylamine, oxidize trimethylamine, dimethylamine, formaldehyde and formate; only bacterium 5B1 and Ps. 3A2 oxidize trimethylamine N-oxide; only bacterium 4B6 does not oxidize methylamine. 3. Cell-free extracts of trimethylamine-grown bacteria 4B6 and C2A1 contain a trimethylamine dehydrogenase that requires phenazine methosulphate as primary hydrogen acceptor, and evidence is presented that this enzyme is important for the growth of bacterium 4B6 on trimethylamine. 4. Cell-free extracts of eight facultative methylotrophs, including bacterium 5B1 and Ps. 3A2, do not contain trimethylamine dehydrogenase but contain instead a trimethylamine monooxygenase and trimethylamine N-oxide demethylase. It is concluded that two different pathways for the oxidation of trimethylamine occur amongst the isolates.

The Tempo and mode(S) of Prebiotic Evolution

1997 ◽  
Vol 161 ◽  
pp. 419-429 ◽  
Author(s):  
Antonio Lazcano
Keyword(s):  
Origin Of Life ◽  
Organic Compounds ◽  
Biological Evolution ◽  
Current Evidence ◽  
Early Diversification ◽  
Time Period ◽  
The Galaxy ◽  
History Of ◽  
Widespread Phenomenon ◽  
The Origin Of Life

AbstractDifferent current ideas on the origin of life are critically examined. Comparison of the now fashionable FeS/H2S pyrite-based autotrophic theory of the origin of life with the heterotrophic viewpoint suggest that the later is still the most fertile explanation for the emergence of life. However, the theory of chemical evolution and heterotrophic origins of life requires major updating, which should include the abandonment of the idea that the appearance of life was a slow process involving billions of years. Stability of organic compounds and the genetics of bacteria suggest that the origin and early diversification of life took place in a time period of the order of 10 million years. Current evidence suggest that the abiotic synthesis of organic compounds may be a widespread phenomenon in the Galaxy and may have a deterministic nature. However, the history of the biosphere does not exhibits any obvious trend towards greater complexity or «higher» forms of life. Therefore, the role of contingency in biological evolution should not be understimated in the discussions of the possibilities of life in the Universe.

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