Caloramator coolhaasii sp.nov., a glutamate-degrading, moderately thermophilic anaerobe

An obligately anaerobic, moderately thermophilic, glutamate-degrading bacterium (strain Z(T)) was isolated from an enrichment culture obtained from anaerobic thermophilic granular sludge. The cells were rod-shaped to filamentous and showed no motility or spore formation. The cell wall had a Gram-positive structure, which was revealed by electron microscopy. Optimum growth of the strain was observed under neutrophilic conditions at 50--55 degrees C. The doubling time of strain Z(T) grown in rich medium was approximately 1 h at optimal pH and temperature. Strain Z(T) was able to grow on a variety of organic compounds. Most carbon sources were converted to acetate, CO(2), H(2), and traces of propionate and lactate. Strain Z(T) oxidized glutamate to acetate, CO(2), NH( )(4), traces of propionate and H(2). The doubling time on this substrate was 1.6 d. The strain fermented glutamate syntrophically in co-culture with Methanobacterium thermoautotrophicum Z-245(T) to the same products, but the co-culture had a fourfold higher growth rate. 16S rDNA sequence analysis revealed a relationship with Thermobrachium celere, Caloramator indicus and Caloramator proteoclasticus. The G C content was 31.7 molÐBased on its morphological, phylogenetic and physiological characteristics, it is proposed that strain Z(T) should be classified in the genus Caloramator as a new species, Caloramator coolhaasii.

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Bibliographic Details
Main Authors: Plugge, C.M., Zoetendal, E.G., Stams, A.J.M.
Format: Article/Letter to editor biblioteca
Language:English
Subjects:Caloramator coolhaasii sp. nov., Glutamate degradation, Interspecies hydrogen transfer, Methanogenic archaea, Syntrophic consortia,
Online Access:https://research.wur.nl/en/publications/caloramator-coolhaasii-spnov-a-glutamate-degrading-moderately-the
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Description
Summary:An obligately anaerobic, moderately thermophilic, glutamate-degrading bacterium (strain Z(T)) was isolated from an enrichment culture obtained from anaerobic thermophilic granular sludge. The cells were rod-shaped to filamentous and showed no motility or spore formation. The cell wall had a Gram-positive structure, which was revealed by electron microscopy. Optimum growth of the strain was observed under neutrophilic conditions at 50--55 degrees C. The doubling time of strain Z(T) grown in rich medium was approximately 1 h at optimal pH and temperature. Strain Z(T) was able to grow on a variety of organic compounds. Most carbon sources were converted to acetate, CO(2), H(2), and traces of propionate and lactate. Strain Z(T) oxidized glutamate to acetate, CO(2), NH( )(4), traces of propionate and H(2). The doubling time on this substrate was 1.6 d. The strain fermented glutamate syntrophically in co-culture with Methanobacterium thermoautotrophicum Z-245(T) to the same products, but the co-culture had a fourfold higher growth rate. 16S rDNA sequence analysis revealed a relationship with Thermobrachium celere, Caloramator indicus and Caloramator proteoclasticus. The G C content was 31.7 molÐBased on its morphological, phylogenetic and physiological characteristics, it is proposed that strain Z(T) should be classified in the genus Caloramator as a new species, Caloramator coolhaasii.