Degradation of barley straw, ryegrass, and alfalfa cell walls by Clostridium longisporum and Ruminococcus albus

Abstract

The recently isolated ruminal sporeforming cellulolytic anaerobe Clostridium longisporum B6405 was examined for its ability to degrade barley straw, nonlignified cell wails (mesophyll and epidermis) and lignified cell walls (fiber) of ryegrass, and alfalfa cell walls in comparison with strains of Ruminococcus albus. R. albus strains degraded 20 to 28% of the dry matter in barley straw in 10 days, while the clostridium degraded less than 2%. A combined inoculum of R. albus SY3 and strain B6405 was no more efficient than SY3 alone, and the presence of Methanobacterium smithii PS did not increase the amount of dry matter degraded. In contrast, with alfalfa cell wails as the substrate, the clostridium was twice as active (28% weight loss) as R. albus SY3 (15%). The percentages of dry matter degraded from ryegrass cell walls of mesophyll, epidermis, and fiber for the clostridium were 50, 47, and 32%, respectively, and for R. albus SY3 they were 77, 73, and 63%, respectively. Analyses of the predominant neutral sugars (arabinose, xylose, and glucose) in the plant residues after bacterial attack were consistent with the values for dry matter weight loss. Measurements of the amount of carbon appearing in the fermentation products indicated that R. albus SY3 degraded ryegrass mesophyll cell walls most rapidly, with epidermis and fiber cell walls being degraded at similar rates. Strain B6405 attacked alfalfa cell walls at a rate greater than that of any of the ryegrass substrates. These results indicate an unexpected degree of substrate specificity in the ability of C. longisporum to degrade plant cell wall material.

Dynamic Distribution of the Gut Microbiota and the Relationship with Apparent Crude Fiber Digestibility and Growth Stages in Pigs

“…The bacterial abundances of Anaeroplasma , Campylobacter , Caulobacter , Cloacibacillus , Enterococcus , Lactobacillus , Methanobrevibacter , Nitrosospira , Propionibacterium , Pseudomonas , Robinsoniella , Staphylococcus and Treponema differed among the groups and were positively correlated with apparent ADF digestibility ( P <0.05) ( Table 3 ). Only Clostridium was related to the metabolism of dietary fiber 27 , which indicates that the other genera may be associated with apparent CF and ADF digestibility. However, no relationship was found between the microbiota and apparent CP digestibility among the three groups in this study.…”

The hydrolysis of lucerne cell‐wall monosaccharide components by monocultures or pair combinations of defined ruminal bacteria

“…In an earlier study, Dehority & Scott (1967) used lucerne hay and reported higher cellulose degradation values for R. albus 7 and three strains of R. Jlavefaciens, and lower hemicellulose degradation values for F. succinogenes S85 and A3C. On the other hand, Varel et al (1989) used intact lucerne CW as substrate and found that several strains of R. albus were not very active in cellulose and xylan degradation, and their findings support the results obtained in this study with R. albus 7 (Table 2). This discrepancy between the earlier study and the more recent studies can be explained by the usage of whole lucerne hay instead of intact CW as the sole substrate by Dehority & Scott (1967) and thus encouraging activity and growth of ruminococci and interfering with activity of F. succinogenes, as demonstrated in previous studies (Miron & Yokoyama 1990;Miron et al 1990).…”

“…It is well accepted that the predominant rumen bacteria that degrade native CW are acting in consortia (Cheng et al 1983), but the mechanism of interaction between bacterial species is still fragmentary (Dehority & Scott 1967;Collings & Yokoyama 1980;Kopecny & Williams 1988;Osborne & Dehority 1989;Varel et al 1989).…”

Addition of cellulolytic clostridia to the bovine rumen and pig intestinal tract

“…These four pigs were also fed a 40% ground alfalfa and corn-soy diet. Enrichment media contained 0.5 g of alfalfa cell walls (19), 26 ml of McDougall's buffer (11), and 2 g (wet weight) of fecal sample, and half of the cultures received a 2-ml culture of C. longisporum OC4 (10 7 viable cells ml Ϫ1 ). The other half of the cultures (four controls) received an additional 2 ml of buffer.…”