Glycerol Degradation by Desulfovibrio SP. in Pure Culture and in Coculture with Methanospirillum Hungatei

1990 ◽  
pp. 447-449
Author(s):  
A. I. Qatibi ◽  
J.-L. Cayol ◽  
J.-L. Garcia
Keyword(s):  
Pure Culture ◽  
Methanospirillum Hungatei

scholarly journals Propionate Formation by Opitutus terrae in Pure Culture and in Mixed Culture with a Hydrogenotrophic Methanogen and Implications for Carbon Fluxes in Anoxic Rice Paddy Soil

2002 ◽  
Vol 68 (4) ◽  
pp. 2089-2092 ◽  
Author(s):  
Kuk-Jeong Chin ◽  
Peter H. Janssen
Keyword(s):  
Paddy Soil ◽  
Pure Culture ◽  
Carbon Flux ◽  
Rice Paddy ◽  
Rice Paddy Soil ◽  
Hydrogenotrophic Methanogen ◽  
Methanospirillum Hungatei ◽  
Partial Pressures ◽  
Important Intermediate ◽  
Propionate Formation

ABSTRACT Propionate-forming bacteria seem to be abundant in anoxic rice paddy soil, but biogeochemical investigations show that propionate is not a correspondingly important intermediate in carbon flux in this system. Mixed cultures of Opitutus terrae strain PB90-1, a representative propionate-producing bacterium from rice paddy soil, and the hydrogenotrophic Methanospirillum hungatei strain SK maintained hydrogen partial pressures similar to those in the soil. The associated shift away from propionate formation observed in these cultures helps to reconcile the disparity between microbiological and biogeochemical studies.

scholarly journals Benzoate Fermentation by the Anaerobic BacteriumSyntrophus aciditrophicus in the Absence of Hydrogen-Using Microorganisms

2001 ◽  
Vol 67 (12) ◽  
pp. 5520-5525 ◽  
Author(s):  
Mostafa S. Elshahed ◽  
Michael J. McInerney
Keyword(s):  
Free Energy ◽  
Pure Culture ◽  
Growth Yield ◽  
Dry Weight ◽  
Minimum Free Energy ◽  
High Hydrogen ◽  
Methanospirillum Hungatei ◽  
Cyclohexane Carboxylate ◽  
Pure Cultures ◽  
Syntrophus Aciditrophicus

ABSTRACT The anaerobic bacterium Syntrophus aciditrophicusmetabolized benzoate in pure culture in the absence of hydrogen-utilizing partners or terminal electron acceptors. The pure culture of S. aciditrophicus produced approximately 0.5 mol of cyclohexane carboxylate and 1.5 mol of acetate per mol of benzoate, while a coculture of S.aciditrophicus with the hydrogen-using methanogenMethanospirillum hungatei produced 3 mol of acetate and 0.75 mol of methane per mol of benzoate. The growth yield of theS. aciditrophicus pure culture was 6.9 g (dry weight) per mol of benzoate metabolized, whereas the growth yield of the S. aciditrophicus-M. hungatei coculture was 11.8 g (dry weight) per mol of benzoate. Cyclohexane carboxylate was metabolized by S. aciditrophicus only in a coculture with a hydrogen user and was not metabolized by S. aciditrophicus pure cultures. Cyclohex-1-ene carboxylate was incompletely degraded by S. aciditrophicus pure cultures until a free energy change (ΔG′) of −9.2 kJ/mol was reached (−4.7 kJ/mol for the hydrogen-producing reaction). Cyclohex-1-ene carboxylate, pimelate, and glutarate transiently accumulated at micromolar levels during growth of an S. aciditrophicus pure culture with benzoate. High hydrogen (10.1 kPa) and acetate (60 mM) levels inhibited benzoate metabolism byS. aciditrophicus pure cultures. These results suggest that benzoate fermentation by S. aciditrophicus in the absence of hydrogen users proceeds via a dismutation reaction in which the reducing equivalents produced during oxidation of one benzoate molecule to acetate and carbon dioxide are used to reduce another benzoate molecule to cyclohexane carboxylate, which is not metabolized further. Benzoate fermentation to acetate, CO2, and cyclohexane carboxylate is thermodynamically favorable and can proceed at free energy values more positive than −20 kJ/mol, the postulated minimum free energy value for substrate metabolism.

scholarly journals Proteomic Analysis of a Syntrophic Coculture of Syntrophobacter fumaroxidans MPOBT and Geobacter sulfurreducens PCAT

2021 ◽  
Vol 12 ◽  
Author(s):  
Monir Mollaei ◽  
Maria Suarez-Diez ◽  
Vicente T. Sedano-Nunez ◽  
Sjef Boeren ◽  
Alfons J. M. Stams ◽  
...  
Keyword(s):  
Pure Culture ◽  
Formate Dehydrogenase ◽  
Geobacter Sulfurreducens ◽  
Acetate Metabolism ◽  
Differential Abundance ◽  
Methanospirillum Hungatei ◽  
Interspecies Electron Transfer ◽  
Lower Abundance ◽  
Associated Proteins ◽  
Propionate Degradation

We established a syntrophic coculture of Syntrophobacter fumaroxidans MPOBT (SF) and Geobacter sulfurreducens PCAT (GS) growing on propionate and Fe(III). Neither of the bacteria was capable of growth on propionate and Fe(III) in pure culture. Propionate degradation by SF provides acetate, hydrogen, and/or formate that can be used as electron donors by GS with Fe(III) citrate as electron acceptor. Proteomic analyses of the SF-GS coculture revealed propionate conversion via the methylmalonyl-CoA (MMC) pathway by SF. The possibility of interspecies electron transfer (IET) via direct (DIET) and/or hydrogen/formate transfer (HFIT) was investigated by comparing the differential abundance of associated proteins in SF-GS coculture against (i) SF coculture with Methanospirillum hungatei (SF-MH), which relies on HFIT, (ii) GS pure culture growing on acetate, formate, hydrogen as propionate products, and Fe(III). We noted some evidence for DIET in the SF-GS coculture, i.e., GS in the coculture showed significantly lower abundance of uptake hydrogenase (43-fold) and formate dehydrogenase (45-fold) and significantly higher abundance of proteins related to acetate metabolism (i.e., GltA; 62-fold) compared to GS pure culture. Moreover, SF in the SF-GS coculture showed significantly lower abundance of IET-related formate dehydrogenases, Fdh3 (51-fold) and Fdh5 (29-fold), and the rate of propionate conversion in SF-GS was 8-fold lower than in the SF-MH coculture. In contrast, compared to GS pure culture, we found lower abundance of pilus-associated cytochrome OmcS (2-fold) and piliA (5-fold) in the SF-GS coculture that is suggested to be necessary for DIET. Furthermore, neither visible aggregates formed in the SF-GS coculture, nor the pili-E of SF (suggested as e-pili) were detected. These findings suggest that the IET mechanism is complex in the SF-GS coculture and can be mediated by several mechanisms rather than one discrete pathway. Our study can be further useful in understanding syntrophic propionate degradation in bioelectrochemical and anaerobic digestion systems.

Impact of Transfaunation of Rumen Ciliate Cultures on Physical Examination, Selected Serum Parameters and Milk Profile in Defaunated Lactating Dairy Goats

2020 ◽  
Keyword(s):  
Physical Examination ◽  
Mixed Culture ◽  
Pure Culture ◽  
Milk Fat ◽  
Mixed Cultures ◽  
Dairy Goats ◽  
Serum Parameters ◽  
Native Breed ◽  
Culture Duration ◽  
Inorganic Phosphorous

Rumen ciliates still have mysterious secrets and influences in ruminants. This study investigated the effect of transfaunation of pure and mixed cultures of rumen ciliates on physical clinical examination, selected serum parameters and milk profile in defaunated lactating dairy goats. A number of 8 Baladi native breed goats were randomly classified into two groups each one containing 4 goats. Pure culture group was transfaunated with 6 ml of pure culture of Holotricha spp., while mixed culture group was transfaunated with 6 ml of mixed culture of 81.85% Holotricha and 18.15% Ophryoscolex spp. once weekly for three consecutive weeks, after defaunation of both groups using 30 ml of 8% SLS for two consecutive days. Serum and milk samples were collected weekly for three successive weeks to study effect of type of ciliate culture, duration of transfaunation and their interaction. Results revealed that transfaunation of pure and mixed cultures of rumen ciliates had no effect on physical examination with minimal non-significant improvement of calcium, inorganic phosphorous, total protein and globulin in serum of defaunated goats. Transfaunation of pure or mixed cultures of rumen ciliates within three weeks could not improve significantly decreased milk fat % of defaunated goats without any effect on other measured milk profile parameters. It is concluded that further investigations on transfaunation without prior defaunation should be performed using different pure and mixed cultures of rumen ciliates for therapeutic and productive purposes.

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