Improved techniques for dissociating particle-associated mixed ruminal microorganisms from ruminal digesta solids2

Abstract

Combinations of physical and chemical methods were evaluated for their ability to remove particle-associated microorganisms (PAM) from saline-washed ruminal digesta solids (SWRDS). Physical methods included chilling and storage, homogenization, multiple extraction, and agitation with marbles. Chemical methods included use of low pH, Tween 80, formaldehyde, methanol, tertiary butanol, and methylcellulose. Microbial removal from SWRDS was determined directly by using epifluorescence microscopy and indirectly by measuring removal of diaminopimelic acid and total purines. Different combinations of methods resulted in removals of 46 to 82% for particle-associated bacteria (PAB), 52 to 98% for particle-associated protozoa (PAP), and 60 to 83% for PAB plus PAP. Two methods were considered most effective, based on microscopy; both removed similar amounts of PAB (79 to 82%) and PAB plus PAP (80 to 83%). In one method, SWRDS were stored for 24 h at 4 degrees C in a solution of pH 2 saline, .1% Tween 80, 1.0% methanol, and 1.0% tertiary butanol. In the other method, SWRDS were incubated for 30 min in .1% methylcellulose before storage for 24 h at 4 degrees C in pH 2 saline, .1% Tween 80, and 1.0% methanol. Common to both treatments was subsequent homogenization of the suspensions for 15 s followed by washing the digesta solids seven times with the treatment solutions. Both methods resulted in values that exceeded those reported previously for removal of PAM from ruminal digesta solids.

Evaluación de suplementos alimenticios conteniendo torta de higuerilla sobre la degradación in situ de dietas con pasto kikuyo y la producción lechera en vacas Holstein

“…Ingredientes utilizados en la formulación de los suplementos evaluados in situ y su composición química en dietas compuestas por 70 % de pasto kikuyo y 30 % de concentrado. Todas las bolsas fueron pesadas en una balanza analítica, antes y después de la incubación intraruminal, para determinar la degradabilidad in situ de la MS, fibra detergente neutra (FDN-DFDN) y de la proteína bruta (PB-DPB); para esta última fracción, fue corregida previamente por la contaminación con nitrógeno de origen microbiano, utilizando una solución al 0,1 % de metilcelulosa 70 . La degradabilidad in situ de cada una de las fracciones, se calculó como la diferencia entre la cantidad de MS incubada y la MS residual, teniendo en cuenta la concentración de PB y de la FDN.…”

Effect of Incremental Urea Supplementation of a Conventional Corn Silage-Based Diet on Ruminal Ammonia Concentration and Synthesis of Microbial Protein

“…Isolation of bacteria followed the procedures of Whitehouse et al (1994) and Putnam et al (1997). Isolated bacteria were lyophilized, and fluid-and particle-associated bacteria were then combined.…”

Effect of white-rot basidiomycetes-treated wheat straw on rumen fermentation in artificial rumen

“…The concentration of ammonia-nitrogen in the effluent was determined by the microdiffusion method (Conway and O'Malley, 1942). The microbial biomass in the residues were determined by an improved technique using treatment with saline (pH 2.0), Tween 80, MeOH and terciary butanol (Whitehouse et al, 1994). …”