Clostridium proteoclasticum: a ruminal bacterium that forms stearic acid from linoleic acid

• Published in: FEMS microbiology letters Vol. 265; no. 2; pp. 195 - 201
• Main Authors: Wallace, R. John, Chaudhary, Lal C., McKain, Nest, McEwan, Neil R., Richardson, Anthony J., Vercoe, Philip E., Walker, Nicola D., Paillard, Delphine
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.12.2006; Blackwell; Oxford University Press
• Subjects: Acids; Animals; Bacteria; Bacteriology; biohydrogenation; Biological and medical sciences; Butyrivibrio; Cattle; Clostridium; Clostridium - isolation & purification; Clostridium - metabolism; Clostridium proteoclasticum; Fundamental and applied biological sciences. Psychology; Fusocillus; Gram-positive bacteria; Hydrogenation; Linoleic acid; Linoleic Acid - metabolism; Metabolism. Enzymes; Microbiology; Morphology; Phylogeny; Proteolysis; RNA, Ribosomal, 16S - classification; rRNA 16S; Sheep; Sheep - microbiology; stearate; Stearic acid; Stearic Acids - metabolism; Stomach, Ruminant - microbiology; biohydrogenation; stearate; Butyrivibrio; Clostridium; Clostridiaceae; Stearate; Clostridiales; Bacteria; Hydrogenation; Linoleic acid; Clostridium proteoclasticum; Fusocillus
• ISSN: 0378-1097; 1574-6968
• DOI: 10.1111/j.1574-6968.2006.00487.x

Abstract The aim of this study was to identify ruminal bacteria that form stearic acid (18 : 0) from linoleic acid (cis-9,cis-12-18 : 2). One 18 : 0-producing isolate, P-18, isolated from the sheep rumen was similar in morphology and metabolic properties to ‘Fusocillus’ spp. isolated many years ago. Phylogenetic analysis based on nearly full-length 16S rRNA gene sequence (> 1300 bp) analysis indicated that the stearate producer was most closely related to Clostridium proteoclasticum B316T. Clostridium proteoclasticum B316T was also found to form 18 : 0, as were other bacteria isolated elsewhere, which occurred in the same family subclass of the low G+C% Gram-positive bacteria, related to Butyrivibrio fibrisolvens. These bacteria are not clostridia, and the ability to form 18 : 0 was present in all strains in contrast to proteolytic activity, which was variable. Production of 18 : 0 occurred in growing, but not in stationary-phase, bacteria, which made detection of biohydrogenating activity difficult, because of the inhibitory effects of linoleic acid on growth.