The Cellulolytic Activity of Pure Strains of Bacteria from the Rumen of Cattle

Abstract

SUMMARYThe in vitro breakdown of degraded and undegraded varieties of cellulose was examined by using pure strains of bacteria isolated from the rumen of cattle. One strain of Bacteroides succinogenes, two strains of Ruminococcus albus and two strains of Ruminococcus jlavefaciens were allowed to ferment ground cellulose powder (prepared from filter paper), cellulose powder (Whatman) and undegraded cotton fibres, the extent of breakdown being followed by loss of weight of the insoluble substrate.All five organisms were highly active on degraded ground cellulose powder and dissolved 72-90 yo, but only one organism, B. succinogenes strain s-85, was equally effective on cellulose powder (Whatman) or on undegraded cotton fibres. R. jlavefaciens strain FD-1 was somewhat less potent on the latter substrates, achieving 40 and 60 yo dissolution, respectively, of cellulose powder (Whatman) and cotton fibres. R. albus strain 7 and R. Jlavefaciens strain c-94 had negligible effects on cotton fibres (10 and 0 Yo solubilization, respectively). R. albus strain D-89, producing 40 yo solubilization of cotton fibres, was intermediate in activity between R. albus strain 7 and R. Jlavefaciens strain FD-'I. Cell-free preparations from culture filtrates of B. succinogenes strain s-85 gave only 4 yo breakdown of ground cellulose powder and up to 9 yo breakdown of cellulose powder (Whatman) in 17 days. Cell-free filtrates from the metabolism fluid of R.flavefaciens strain FD-1 or from the disintegrated organisms brought about 46 and 36 yo solubilization, respectively, of ground cellulose powder, but failed to attack cotton fibres. The results support the view that the capacity of an organism or cell-free enzyme to attack any one particular form of cellulose is no criterion of its ability to attack less degraded or undegraded types of cellulose.

Preliminary studies on the bacterial flora of faeces taken from foals, from birth to twelve weeks. Effect of the oral administration of a commercial colostrum replacer

“…The total anaerobes were estimated at '106 and 107 on rolltubes containing a solid medium (Leedle and Hespeil 1980) after 120 h of incubation at 39'C. Cellulolytic flora was estimated at 102, 103 and 104 for foals prior to 1 month and at 103, '104 and '105 for the older animals, on a specific liquid medium (Halliwell and Bryant 1953) after two weeks of incubation at 39"C. Clostridia were determined at 105, 106 and 107 on a reduced commercial Brain-Heart infusion (Bio-Merieux) after 120 h of incubation at 3O'C. To select the clostridia (spore-forming bacteria) the 102 dilution was heated at 75"C for 10 mi-NUTCS.…”

A Comparison of Two Techniques for Counting Cellulolytic Rumen Bacteria

“…In the case of the 'direct' method, the nature of the cellulose substrate may influence the counts. Certain forms of cellulose are not readily utilized by all strains of cellulolytic rumen bacteria (Halliwell & Bryant, 1963 ;Hungate, 1966;Shane, 1966). Moreover, if the cellulose substrate is not sufficiently ground the substrate is not homogeneously distributed throughout the medium.…”

Digestion in Ruminants

“…F. succinogenes has a potent ability to solubilize crystalline chains of cellulose (Halliwell and Bryant, 1963;Shinkai and Kobayashi, 2007). F. succinogenes produces primarily succinate (a propionate precursor), and lesser amounts of acetate, R. flavefaciens produces primarily acetate and lesser amounts of succinate converts to propionate by Selenomonas ruminantium (Weimer at al., 1999).…”