scholarly journals Prevotella ruminicola

2020 ◽  
Author(s):  
Keyword(s):  
Prevotella Ruminicola

Nomenclature Abstract for Prevotella ruminicola brevis (Bryant et al. 1958) Avguštin et al. 1997.

2003 ◽  
Author(s):  
Charles Thomas Parker ◽  
Nicole Danielle Osier ◽  
George M Garrity ◽  
Dorothea Taylor
Keyword(s):  
Prevotella Ruminicola

scholarly journals Biochemical Analysis of a β-d-Xylosidase and a Bifunctional Xylanase-Ferulic Acid Esterase from a Xylanolytic Gene Cluster in Prevotella ruminicola 23

2009 ◽  
Vol 191 (10) ◽  
pp. 3328-3338 ◽  
Author(s):  
Dylan Dodd ◽  
Svetlana A. Kocherginskaya ◽  
M. Ashley Spies ◽  
Kyle E. Beery ◽  
Charles A. Abbas ◽  
...  
Keyword(s):  
Recombinant Protein ◽  
Ferulic Acid ◽  
Biochemical Analysis ◽  
Directed Mutagenesis ◽  
Ferulic Acid Esterase ◽  
Prevotella Ruminicola ◽  
Obligate Anaerobic ◽  
Catalytic Sites ◽  
Cellular Machinery ◽  
Biochemical Analyses

ABSTRACT Prevotella ruminicola 23 is an obligate anaerobic bacterium in the phylum Bacteroidetes that contributes to hemicellulose utilization within the bovine rumen. To gain insight into the cellular machinery that this organism elaborates to degrade the hemicellulosic polymer xylan, we identified and cloned a gene predicted to encode a bifunctional xylanase-ferulic acid esterase (xyn10D-fae1A) and expressed the recombinant protein in Escherichia coli. Biochemical analysis of purified Xyn10D-Fae1A revealed that this protein possesses both endo-β-1,4-xylanase and ferulic acid esterase activities. A putative glycoside hydrolase (GH) family 3 β-d-glucosidase gene, with a novel PA14-like insertion sequence, was identified two genes downstream of xyn10D-fae1A. Biochemical analyses of the purified recombinant protein revealed that the putative β-d-glucosidase has activity for pNP-β-d-xylopyranoside, pNP-α-l-arabinofuranoside, and xylo-oligosaccharides; thus, the gene was designated xyl3A. When incubated in combination with Xyn10D-Fae1A, Xyl3A improved the release of xylose monomers from a hemicellulosic xylan substrate, suggesting that these two enzymes function synergistically to depolymerize xylan. Directed mutagenesis studies of Xyn10D-Fae1A mapped the catalytic sites for the two enzymatic functionalities to distinct regions within the polypeptide sequence. When a mutation was introduced into the putative catalytic site for the xylanase domain (E280S), the ferulic acid esterase activity increased threefold, which suggests that the two catalytic domains for Xyn10D-Fae1A are functionally coupled. Directed mutagenesis of conserved residues for Xyl3A resulted in attenuation of activity, which supports the assignment of Xyl3A as a GH family 3 β-d-xylosidase.

Identification and characterisation of the predominant lactic acid-producing and lactic acid-utilising bacteria in the foregut of the feral camel (Camelus dromedarius) in Australia

2011 ◽  
Vol 51 (7) ◽  
pp. 597 ◽  
Author(s):  
M. B. Ghali ◽  
P. T. Scott ◽  
G. A. Alhadrami ◽  
R. A. M. Al Jassim
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Volatile Fatty Acids ◽  
Camelus Dromedarius ◽  
Rrna Gene ◽  
Acid Media ◽  
Butyrivibrio Fibrisolvens ◽  
Prevotella Ruminicola ◽  
De Man

The camel is emerging as a new and important animal in the Australian livestock industry. However, little is known regarding the microbial ecosystem of the gastrointestinal tract of this ruminant-like animal. This study was carried out to determine the diversity of lactic acid-producing and lactic acid-utilising bacteria in the foregut of the feral camel (Camelus dromedarius) in Australia. Putative lactic acid bacteria were isolated from the foregut contents of camels by culturing on De Man, Rogosa, Sharpe and lactic acid media. Identification of representative isolates was based on the analysis of 16S rRNA gene sequences. Fermentation end products of glucose (i.e. volatile fatty acids and lactate) were also measured in vitro. The key predominant bacteria identified in this study were closely related to Streptococcus bovis, Selenomonas ruminantium, Butyrivibrio fibrisolvens, Lachnospira pectinoschiza and Prevotella ruminicola. The main L-lactate producers were those isolates closely related to S. bovis, S. ruminantium and Lactococcus garvieae, while the efficient lactate utilisers were S. ruminantium-related isolates. D-lactate was produced by isolates closely related to either L. pectinoschiza or S. ruminantium. The predominant bacteria isolated and characterised in this study are identical and/or closely related to those typically found in true ruminants (e.g. S. ruminantium, B. fibrisolvens, S. bovis). In addition, some of the bacteria isolated represent novel species of Lachnospira and Clostridium in the context of lactic acid bacteria from a large herbivorous host. The results from this study have contributed to our understanding and provide opportunities to reduce foregut acidosis in the camel.

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