Effects of Physicochemical Factors on the Adhesion to Cellulose Avicel of the Ruminal Bacteria Ruminococcus flavefaciens and Fibrobacter succinogenes subsp. succinogenes

Abstract

Ruminococcus flavefaciens adhered instantly to cellulose, while Fibrobacter succinogenes had the highest percentage of adherent cells after about 25 min of contact between bacteria and cellulose. Adhesion of R. flavefaciens was unaffected by high concentrations of sugars (5%), temperature, pH, oxygen, metabolic inhibitors, and lack of Na+. In contrast, the attachment was affected by the removal of divalent cations (Mg2+ and Ca2+), the presence of cellulose derivatives (methylcellulose and hydroxyethylcellulose), and cystine. Adhesion of F. succinogenes was sensitive to low and high temperatures, high concentrations of glucose and cellobiose (5%), hydroxyethylcellulose (0.1%), redox potential, pH, lack of monovalent cations, and the presence of an inhibitor of membrane ATPases or lasalocid and monensin. Cells of F. succinogenes heated at 100°C no longer were adherent. On the other hand, adhesion was insensitive to the lack of divalent cations (Mg2+ and Ca2+), the presence of 2,4-dinitrophenol, tetrachlorosalicylanilide, or inhibitors of the electron transfer chains. Adhesion of F. succinogenes seems to be related to the metabolic functions of the cell. External proteins and/or cellulases themselves might play a part in the attachment process. Several mechanisms are probably involved in the adhesion of R. flavefaciens, the main one being the interaction between the large glycocalyx and the divalent cations Ca2' and Mg2+. Hydrophobic bonds and enzymes may also be involved.

Adhesive properties of five mesophilic, cellulolytic Clostridia isolated from the same biotope

“…In both strains adhesion was enhanced by the presence of calcium. This is a general phenomenon in cellulolytic bacteria [3,7,8]. Adhesion of these anaerobic bacteria was not influenced by oxydation (experiments with DTT); conversely, adhesion of the two strains is regulated differently by the end-products of cellulolyse: cellobiose and glucose influenccct C401 adhesion whereas adhesion of strain A22 was not sensible to these compounds.…”

“…Since 80-88% of the cells could be released from cellulose by two washes (see MA'I'I-:RIALS ANt) M~-:rltotgS) and could adhere again, adhesion of Table 2 Inhibition of strain C401 adhesion by strain A22 " Cells density (strain C401) (mgdw) ml 1) ('ells adhered (strain C401) 10 3 mg dw) cm 2 all isolates to cellulose was, at least in part, reversible. Adhesion of strain A22 to Whatman filter paper has been demonstrated as a largely specific process [4] of many cellulolytic bacteria [3,4,7,8]. Adhcsion analysis of the other isolates revealed the same specificity of attachment to the cellulose.…”

“…Bacterial adhesion to the substratc is an important step in thc ccllulolytic process [3,5,7,8]. To try to understand how these strains co-exist in the same biotopc and thcir respective contribution to the degradation of lignocellulosic compounds, morc knowlcdgc is needed about the factors affecting adhesion of these strains to cellulosic materials.…”

Rumen Metabolites and Microbiome of Semi-intensively Managed West African Dwarf Goats Supplemented Concentrate Diet of Varying Levels of Sodium Humate

“…The pH level of the rumen is important because fibrolytic bacteria are very sensitive towards pH changes [24]. Tolerable level of pH for fibrolytic bacterial is between 6.0 and 7.0 [25]. Van Soest [26] has reported optimal ruminal pH ranges to be 6.10-6.80 for rumen microbial proliferation.…”

Effects of Saccharomyces cerevisiae supplementation on apparent total tract digestibility of nutrients and fermentation profile in healthy horses

“…One main function of SC seems to be the removal of oxygen, thus protecting the strictly anaerobic bacteria, namely the cellulolytic microflora (Newbold et al, 1996;Marden et al, 2008;Chaucheyras-Durand and Durand, 2010). Oxygen (O 2 ) is lethal to anaerobic bacteria, and it has been shown that oxygen inhibits the growth and the adhesion of rumen cellulolytic bacteria to cellulose (Roger et al, 1990).…”