Chapter 19 Manipulation and characterization of the rumen ecosystem through biotechnology

McAllister, Tim A.; Forster, Robert J.; Teather, R. M.; Sharma, Ranjana; Attwood, Graeme T.; Selinger, L. Brent; Joblin, K. N.

doi:10.1016/s1877-1823(09)70106-7

Cited by 6 publications

(8 citation statements)

References 132 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…However, microbes and, therefore, rumen environment have limited capacity to digest cellulose substances compared to other polysaccharides such as starch or proteins. Currently, more than 200 species of bacteria are isolated from the rumen (McAllister et al 2006). In fact, ruminal fermentation is a complex system and manipulation may not always be successful although other variables of the ecosystem are closely controlled.…”

Section: Modification Of Ruminant Digestive Systemmentioning

confidence: 99%

“…Presumably, manipulation of the rumen system can be achieved by feed manipulation, host animal manipulation, and microbial manipulation (Nagaraja 2012). When it was discovered that ruminants can survive without protozoa (Lindsay and Hogan 1972), protozoal predation of bacteria by protozoa attachment to the fiber particles from outer layers (McAllister et al 2006) and their symbiotic living with methanogens and, therefore, decreasing ruminal protein metabolism (Finlay et al 1994), attempts were made to decrease or get rid of ruminal protozoa (Hristov et al 2003). Since microorganisms utilize the major nutrients of plants, such as cell wall polysaccharides, their efficiency is considered manipulable.…”

Section: Modification Of Ruminant Digestive Systemmentioning

confidence: 99%

“…Additionally, mycoplasmas and bacteriophages are natural residents of the rumen and may share their functions with other living organisms (McAllister et al 2006). Methanogens attracted attention previously only for the loss of energy from the ruminant; currently, because of global warming attempts are toward reducing methane emission by culturing and trying to decrease their growth.…”

Section: Modification Of Ruminant Digestive Systemmentioning

confidence: 99%

See 2 more Smart Citations

The Role of Biotechnology in Improvement of Livestock

Abubakar¹,

Saeed²,

Kul³

2015

View full text Add to dashboard Cite

Section: Modification Of Ruminant Digestive Systemmentioning

confidence: 99%

Section: Modification Of Ruminant Digestive Systemmentioning

confidence: 99%

Section: Modification Of Ruminant Digestive Systemmentioning

confidence: 99%

See 1 more Smart Citation

The Role of Biotechnology in Improvement of Livestock

Abubakar¹,

Saeed²,

Kul³

2015

View full text Add to dashboard Cite

“…Experimental evidence suggests that IgY is reasonably resistant to proteolytic degradation by trypsin or chymotrypsin, possibly because the degradation products [e.g., Fc, Fab, F(ab′) 2 ] retain some immunological activity but it is more sensitive to peptic digestion (Reilly et al 1997). Nonetheless, the ruminant GI tract is a unique environment of extreme conditions with a notably high proteolytic activity in the rumen as a result of resident bacteria (McAllister et al 2005). The relative efficacy observed with the HIGH and MED treatments may be attributable to a proportionally greater amount of dosed IgY evading inactivation as a result of exposure to low pH or degradation by microbial or endogenous proteases.…”

Section: Discussionmentioning

confidence: 99%

Orally administered anti-Escherichia coli O157:H7 chicken egg yolk antibodies reduce fecal shedding of the pathogen by ruminants

Cook¹,

Bach²,

Stevenson³

et al. 2005

Can. J. Anim. Sci.

View full text Add to dashboard Cite

. 2005. Orally administered anti-Escherichia coli O157:H7 chicken egg yolk antibodies reduce fecal shedding of the pathogen by ruminants. Can. J. Anim. Sci. 85: 291-299. Spray-dried whole egg prepared from eggs laid by non-immunized hens (EG) or hens immunized with the C-terminal domain of Escherichia coli O157:H7 intimin (EG-IgY) was fed to experimentally inoculated sheep, to investigate the efficacy of orally administered polyclonal anti-E. coli O157:H7 antibodies (IgY) for reducing the duration and level of fecal shedding of E. coli O157:H7 by ruminants. Thirty Canadian Arcott ram lambs were orally inoculated on day 0 with 10 10 colony-forming units (CFU) of a three-strain mixture of nalidixic acid-resistant E. coli O157:H7. On each of days 2, 3 and 4, the rams (n = 6) were fed 100 g of EG and/or EG-IgY in proportions of 100:0 (CON), 0:100 (HIGH), 50:50 (MED), or 75:25 (LOW). A fifth treatment (denoted variable, VAR) comprised feeding HIGH, MED and LOW on days 2, 3, and 4, respectively. Fecal samples collected on 19 occasions over 85 d (4× in the first wk; 2×/wk for 3 wk; and 1×/wk for 9 wk) were assessed for E. coli O157:H7 by direct plating or enrichment and immunomagnetic separation. Throughout the 85 d, numbers of E. coli O157:H7 shed by the rams were lower (P < 0.001) in HIGH and MED than in CON, and the duration of shedding was shorter (P < 0.005) in HIGH than in CON. Fewer (P < 0.005) samples were culture-positive in HIGH than in CON. Oral dosing of specific IgY has potential to decrease the duration and level of fecal shedding of E. coli O157:H7 by ruminants.

show abstract

“…Even if additional GFP had been produced as a result of cell division within the rumen it would not fluoresce, as oxygen is required to form the cyclical fluorescent chromophore (Heim et al 1994). Ruminal contents are notorious for emitting background florescence, a phenomenon that has impeded the application of fluorescence procedures such as fluorescent in situ hybridization in rumen studies (McAllister et al 2004). Selection of GFP variants specifically to avoid wavelength emissions occurring commonly in rumen contents could further enhance the use of GFP in studies of rumen ecology.…”

Section: Discussionmentioning

confidence: 99%

Development of Pichia pastoris as a rumen escape vehicle for the intestinal delivery of recombinant proteins in ruminants

Strauss¹,

McAllister²,

Selinger³

2004

Can. J. Anim. Sci.

View full text Add to dashboard Cite

Strauss, C. E., McAllister, T. A. and Selinger, L. B. 2004. Development of Pichia pastoris as a rumen escape vehicle for the intestinal delivery of recombinant proteins in ruminants. Can. J. Anim. Sci. 84: 611-619. The effectiveness of cellular encapsulation as a method for delivery of bioactive proteins and limiting amino acids to the small intestine of ruminants was investigated. Intracellular expression of green fluorescent protein variant (GFPuv) in Pichia pastoris was used as a visible marker to assess the cellular integrity of P. pastoris and determine the potential of this approach for protecting recombinant proteins from microbial proteolysis in the rumen. Fluorescent cells were easily identified in the presence of strained ruminal fluid when viewed by epifluorescent microscopy, and intact cells were readily enumerated. Batch cultures with rumen digesta demonstrated that 93, 97 and 25% of P. pastoris cells remained intact after 36 to 48 h of incubation in clarified ruminal fluid, an isolated bacterial fraction, and whole ruminal fluid, respectively. In continuous culture (Rusitec) with a dilution rate of 0.75 d -1 , 19% of P. pastoris cells flowed intact from the fermentation vessels. In vitro abomasal simulations demonstrated that 84% of inoculated P. pastoris had lysed within 12 h of incubation, a property that is necessary for the release of encapsulated protein prior to the small intestine. These in vitro studies suggest that P. pastoris may be an effective vehicle for post-ruminal delivery of bioactive proteins in ruminants. Les auteurs ont effectué des recherches pour voir si l'encapsulation cellulaire est une méthode efficace pour acheminer les protéines bioactives et les acides aminés limitants jusqu'à l'intestin grêle des ruminants. Ils se sont servis de l'expression intracellulaire du variant à protéine verte fluorescente de Pichia pastoris comme marqueur pour évaluer l'intégrité cellulaire de P. pastoris et voir si cette approche met les protéines recombinantes à l'abri de la protéolyse par les bactéries du rumen. Les cellules fluorescentes sont faciles à identifier par microscopie à fluorescence dans le liquide du rumen filtré et on compte aisément les cellules intactes. La culture par lot des digest du rumen indique que 93 %, 97 % et 25 % des cellules de P. pastoris restent intactes après 36 à 48 heures d'incubation dans le liquide du rumen clarifié, dans une fraction de la microflore et dans le liquide du rumen entier, respectivement. Dans les cultures continues (Rusitec) à un taux de dilution de 0,75 par jour, 19 % des cellules de P. pastoris sortent intactes des cuves de fermentation. La simulation in vitro du passage dans l'abomasum indique que 84 % des cellules de P. pastoris inoculées sont détruites dans les 12 heures d'incubation qui suivent, propriété essentielle à la libération de la protéine encapsulée avant son arrivée dans l'intestin grêle. Ces études in vitro laissent croire que P. pastoris pourrait être un véhicule intéressant pour soustraire les protéines bio-actives à la dégr...

show abstract

Chapter 19 Manipulation and characterization of the rumen ecosystem through biotechnology

Cited by 6 publications

References 132 publications

The Role of Biotechnology in Improvement of Livestock

The Role of Biotechnology in Improvement of Livestock

Orally administered anti-Escherichia coli O157:H7 chicken egg yolk antibodies reduce fecal shedding of the pathogen by ruminants

Development of Pichia pastoris as a rumen escape vehicle for the intestinal delivery of recombinant proteins in ruminants

Contact Info

Product

Resources

About