Effects of extracellular pH and phenolic monomers on glucose uptake by Fibrobacter succinogenes S85

Martin, Scott A.

doi:10.1111/j.1472-765x.1992.tb00715.x

Cited by 10 publications

(7 citation statements)

References 15 publications

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“…In addition to S bouis, the effects of pH on nutrient transport by several predominant ruminal bacteria have been evaluated. Consistent with the sensitivity of F. succinogenes S85 to acidic pH when grown in continuous culture (Russell and Dombrowski, 19801, glucose uptake by S85 decreased as extracellular pH declined from 7.0 to 5.0 (Chow and Russell, 1992;Martin, 1992b). Similarly, when R. albus B199 was exposed to extracellular pH values less than 7.0, glucose uptake was reduced more than 80% (Thurston et al, 1993).…”

Section: Environmental Factors and Nutrient Transportsupporting

confidence: 64%

Nutrient transport by ruminal bacteria: a review

Martin

1994

Journal of Animal Science

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Fermentation pathways have been elucidated for predominant ruminal bacteria, but information is limited concerning the specific transport mechanisms used by these microorganisms for C, energy, and N sources. In addition, it is possible that changes in ruminal environmental conditions could affect transport activity. Five carrier-mediated soluble nutrient transport mechanisms have been identified in bacteria: 1) facilitated diffusion, 2) shock sensitive systems, 3) proton symport, 4) Na+ symport, and the 5) phosphoenolpyruvate phosphotransferase system (PEP-PTS). Several regulatory mechanisms are also involved at the cell membrane to coordinate utilization of different sugars. Recent research has shown that predominant ruminal bacteria are capable of transporting soluble nutrients by several of the mechanisms outlined above. Megasphaera elsdenii, Selenomonas ruminantium, and Streptococcus bovis transport glucose by the PEP-PTS, and S. ruminantium and S. bovis also possess PEP-PTS activity for disaccharides. Glucose PTS activity in S. bovis was highest at a growth pH of 5.0, low glucose concentrations, and a dilution rate of .10 h-1. The cellulolytic ruminal bacterium Fibrobacter succinogenes uses a Na+ symport mechanism for glucose transport that is sensitive to low extracellular pH and ionophores. Sodium also stimulated cellobiose transport by F. succinogenes, and there is evidence for a proton symport in the transport of both arabinose and xylose by S. ruminantium. A chemical gradient of Na+ seems to play an important role in AA transport in several ruminal bacteria. Studying nutrient transport mechanisms in ruminal bacteria will lead to a better understanding of the ruminal fermentation.

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Section: Environmental Factors and Nutrient Transportsupporting

confidence: 64%

Nutrient transport by ruminal bacteria: a review

Martin

1994

Journal of Animal Science

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“…Further studies involving a longer incubation time would help to discern the antibacterial action of PT. There is evidence that this species is sensitive to terrestrial plant secondary compounds 23, 27, 37. In a pure culture study, Bae et al 38 demonstrated that at concentrations up to 800 µg mL −1 , condensed tannins from birdsfoot trefoil were inhibitory, rather than bactericidal, to F. succinogenes .…”

Section: Discussionmentioning

confidence: 99%

In vitro effects of phlorotannins from Ascophyllum nodosum (brown seaweed) on rumen bacterial populations and fermentation

2009

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BACKGROUND: Use of brown algae (seaweed) in ruminant diets is increasing, but the effects of its phlorotannins (PT) on rumen microbial ecology have not been determined. Mixed forage (50 : 25 : 25 ground barley silage-alfalfa hay-grass hay) was used as substrate in a batch culture ruminal incubation that included PT extracted from Ascophyllum nodosum, with and without polyethylene glycol. Principal ruminal bacteria were quantified using real-time polymerase chain reaction.

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“…(Eklund, 1980;Rico-Munoz et al ,.1987;Ruiz-Barba et al, 1990;Denyer and Hugo, 1991;Hugo, 1991;Kabara and Eklund, 1991;Eklund and Nes, 1991;Martin, 1992). In other words the bactericidallbacteriostatic effect of phenolic compounds is shown by perturbations at two different levels: cell wall and membrane integrity as discussed above and the physiological status of bacteria (Kabara and Eklund, 1991).…”

Section: Modes Of Actionmentioning

confidence: 90%