Effects of Sainfoin ( Onobrychis viciifolia Scop.) Condensed Tannins on Growth and Proteolysis by Four Strains of Ruminal Bacteria

Abstract

Sainfoin leaf condensed tannins inhibited growth and protease activity in Butyrivibriofibrisolvens A38 and Streptococcus bovis 45S1 but had little effect on Prevotella ruminicola B14 or Ruminobacter amylophilus WP225. Tannins bound to cell coat polymers in all strains. implicated the cell wall as a target of tannin toxicity. Morphological changes in B. fibrisolvens and S. bovis Condensed tannins (CTs) are generally regarded as antinutritional for ruminants because of depression of feed intake and dry matter digestibility (13, 24), but their capacity to precipitate proteins reversibly at rumen pH may be nutritionally beneficial (14, 15, 20). When CT-containing herbage is masticated, insoluble CT-protein complexes are formed; these are stable over the pH range 3.5 to 7.0 but dissociate in the abomasum and anterior duodenum (11, 16). This protects the protein from microbial hydrolysis and deamination in the rumen and increases the proportion of plant amino acids available for postruminal absorption. Furthermore, the "bloatsafe" property of pasture legumes such as sainfoin (Onobrychis viciifolia Scop.) and birdsfoot trefoil (Lotus corniculatus L.) is correlated with CT content (14, 15). Most of the proteolytic activity of rumen contents resides with the bacterial fraction (3, 8, 17). Soluble plant proteins typically adsorb to the surface of proteolytic bacteria (21) and are hydrolyzed by constitutively expressed cell coat proteases (12, 22). Our objective was to determine some effects of CTs on growth and proteolysis by four strains of ruminal bacteria representing functionally important proteolytic species (23). The CTs used were purified (2) from leaves of sainfoin (cv. Melrose) and had a high protein-precipitating capacity compared with those of CTs from eight other forage legume sources (9). A single batch of sainfoin leaf CTs was used for all experiments. Effects of CTs on bacterial growth. Butyrivibrio fibrisolvens A38, Prevotella ruminicola B14, Ruminobacter amylophilus WP225, and Streptococcus bovis 45S1 were grown anaerobically (4) in a basal medium, which was the medium of Scott and

Microbial population in the rumen of swamp buffalo (Bubalus bubalis) as influenced by coconut oil and mangosteen peel supplementation

“…However, other studies have demonstrated that tannins or saponins and saponin/ tannins-containing plants have antimicrobial properties (Patra and Saxena, 2009). Inhibitory activity of tannins against bacteria has been implicated owing to the ability of tannins to form complexes with the cell wall and membrane of bacteria causing morphological changes of the cell wall and the extracellular enzymes secreted (Jones et al, 1994). Dietary supplementation did not affect methanogen, R. flavefaciens or R. albus abundances.…”

“…It is postulated that by virtue of size, the medium-chain fatty acids are small enough to be readily dissolved in the lipid phase, to penetrate and physically disrupt cell membranes, and to inhibit enzymes involved in energy production and nutrient transfer, leading to reversible and irreversible changes that may lead to the death of the cell. Inhibition of growth of the predominant rumen bacteria by polyphenolics has been demonstrated in vitro with pure cultures (Jones et al, 1994). Although tannins can inhibit rumen micro-organisms, certain bacterial strains that are tannin-tolerant have been isolated from ruminants (Nelson et al, 1998).…”

Effect of steroidal saponin from Yucca schidigera extract on ruminal microbes

“…Samples of the non-cellulolytic bacterial cultures were prepared for transmission electron microscopy (TEM) as described by Jones et al (1994) at the end of the pre-expo-sure period and after 7 and 24 h of incubation with 0 or 250 mg SAP ml À1 . Filter paper residues from the extra set of cultures of cellulolytic bacteria were prepared for SEM as described by Bae et al (1993) and the preparations were viewed using H-500 (TEM) and S-570 (SEM) electron microscopes (Hitachi, Tokyo, Japan).…”

Comparative aspects of plant tannins on digestive physiology, nutrition and microbial community changes in sheep and goats: A review

“…Regardless of many studies (Callaway et al, 2010;Hristov, Callaway, Lee, & Dowd, 2012;Roesch et al, 2007) (2004) reported that when rats were fed tannin diets, F I G U R E 5 Relationship between sheep and goats for ruminal ammonia-N (mg/L) concentration in response to feeding tannincontaining forages (Barry & Manley, 1984;Waghorn et al, 1987Waghorn et al, , 1990Waghorn et al, , 1998Waghorn et al, , 2002Barahona et al, 1997;Woodward and Reed, 1997;Min et al, 2002aMin et al, ,b, 2012Bengaly et al, 2007) (Jones, McAllister, Cheng, & Muir, 1994). These findings also agree with the results of a 16S-rDNA pyrosequencing study of goats fed CT extract from quebracho and chestnut tannins (Min, Solaiman, et al, 2014;Min, Wright, et al, 2014).…”