Clostridium pascui sp. nov., a New Glutamate-Fermenting Sporeformer from a Pasture in Pakistan

Abstract

Four strains of an obligately anaerobic spore-forming bacterium were isolated from soil samples from a donkey pasture in Pakistan. Comparative 16s rRNA sequence analysis demonstrated that the strains are members of phylogenetic cluster I of the genus Clostridium (Collins et al. 1994). The strains are mesophilic, nonsaccharolytic, and nonproteolytic, utilize glutamate and histidine, and produce indole. Acetate, butyrate, ethanol, hydrogen, and carbon dioxide are the products of fermentation. Although the strains phenotypically resemble the classical glutamate-fermenting clostridia, such as Clostridium cochlearium, Clostridium tetanomorphum, Clostridium tetani, and especially Clostridium malenominatum, they differ from these organisms in sugar utilization, cellular fatty acid composition, and cellular protein pattern and by a 16s rRNA sequence divergence value of approximately 4 to 8%. Phylogenetically, the strains are more closely related to Clostridium estertheticum (sequence divergence, approximately 5%) and Clostridium subterminale (sequence divergence, approximately 5%) but are phenotypically readily distinguished from these species. On the basis of phenotypic and genotypic criteria, we conclude that the four strains are members of a new species of the genus Clostridium, for which the name Clostridium pascui is proposed. The type strain is strain Cm19 (= DSM 10365).In the course of previous studies aimed at isolation and characterization of glutamate-fermenting bacteria, which led to the revival of the species Clostridium tetanomoiphum (26), we recovered four clostridial strains which could not be unambiguously identified as strains of any of the classical glutamate-fermenting species, such as Clostridium cochlearium, Clostridium tetanomorphum, Clostridium tetani, Clostridium malenominatum, and Clostridium limosum. When the identification key of Cat0 et al. (3) was used, the strains closely resembled C. malenominatum. However, differences in electrophoretic cellular protein patterns did not support this classification.In an attempt to clarify the taxonomic position of these unknown isolates and to determine their relationships with other glutamate-fermenting species, we conducted further phenotypic and genotypic investigations. On the basis of the findings of these studies, we concluded that the four glutamatefermenting soil isolates represent a new species of the genus Clostridium, for which the name Clostridium pascui is proposed. MATERIALS AND METHODSBacteria. Strains Cm17, Cm19T (T = type strain), Cm20, and Cm21 were isolated from soil samples taken from a donkey pasture in Pakistan. The isolation procedure described by Hippe et al. (13) was used with glutamate as the substrate. The isolates were tested for toxigenicity, and none was positive. Strains of C. mulenominatum (DSM 1127T), C. cochlearium (DSM 666, DSM 667, DSM 2153, DSM 3588, and DSM 1285T), C. tetanomorphum (DSM 528, DSM 665, and DSM 4474T), C. limosum (DSM 1400T), Clostridium symbiosum (DSM 934T), Clostridium subterminale (DSM 758, DSM 2636, ...

Aminomonas paucivorans gen. nov., sp. nov., a mesophilic, anaerobic, amino-acid-utilizing bacterium

“…hydrogenoformans in pure culture (Stams & Hansen, 1984). This trait differentiates it from other amino-acid-degrading members of the genera Acidaminococcus, Peptostreptococcus, Fusobacterium and Clostridium (Rogosa, 1969;Barker, 1981;Wilde et al, 1997), which produce acetate, butyrate, carbon dioxide, ammonium and hydrogen. In contrast to strain GLU-3T, S .…”

“…Strain GLU-3T is a Gram-negative, slightly curved, non-spore-forming, obligate amino-acid-degrading anaerobe and therefore cannot be assigned to the aminolytic members of the genus Clostridium which include Clostridiurn sticklandii and Clostridium aminophilum (Paster et al, 19931, Clostridium litorale, Clostridium pascui and Clostridium hydroxybenzoicum (Fendrich et al, 1990;Wilde et al, 1997;Zhang et al, 1994) and Clostridium acetireducens (Orlygsson et al, 1996). These species are Gram-positive, sporeforming, straight rods.…”

Characterization of novel psychrophilic clostridia from an Antarctic microbial mat: description of Clostridium frigoris sp. nov., Clostridium lacusfryxellense sp. nov., Clostridium bowmanii sp. nov. and Clostridium psychrophilum sp. nov. and reclassification of Clostridium laramiense as Clostridium estertheticum subsp. laramiense subsp. nov.

“…The fatty acid profiles of the Antarctica strains were clearly distinct from the profiles of C. laramiense, C. estertheticum and other related species of the genus Clostridium. The fatty acid C 16 : 1 v9c was the dominant component (25?4-30?7 %) in the novel strains, whereas the fatty acid C 14 : 0 (24?7-34?5 %) was the most abundant component in the patterns of C. laramiense, C. estertheticum and Clostridium pascui (Wilde et al, 1997). The phylogenetically related Clostridium subterminale could be distinguished from the novel strains as it contained about 20 % iso-and anteiso-branched fatty acids (Wilde et al, 1997).…”

“…In all strains studied, fatty acids C 14 : 0 , C 16 : 1 v9c, C 16 : 0 and C 16 : 1 v9c dimethylacetal were among the major components. To analyse the influence of medium composition on the fatty acid pattern of C. estertheticum DSM 8809 T , the values obtained in Wilkins-Chalgren broth were compared with published data obtained from cells grown in PYG broth (Wilde et al, 1997). It turned out that the fatty acid profile of this strain is relatively stable and independent of cultivation medium.…”

Phylogenetic analysis of gram-positive bacteria based on grpE, encoded by the dnaK operon.

“…A comparison of the phylogenetic trees derived by 5S rRNA sequencing (Olsen et al, 1994), 16S rRNA sequencing (de Vaux et al, 1998 ;Macy et al, 1996 ;Morse et al, 1996 ;Stackebrandt et al, 1997 ;Tsakalidou et al, 1998 ;Wilde et al, 1997 ;Zaitsev et al, 1998) and amino acid sequence comparisons for two of the HSPs encoded by the dnaK operon, DnaK (Gupta, 1998) and DnaJ (Bustard & Gupta, 1997) is shown in Fig. 1.…”