Open AccessIn situ identification of carboxymethyl cellulose–digesting bacteria in the rumen of cattle fed alfalfa or triticale
Author(s) -
Kong Yunhong,
Xia Yun,
Seviour Robert,
He Maolong,
McAllister Tim,
Forster Robert
Publication year - 2012
Publication title -
fems microbiology ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.377
H-Index - 155
eISSN - 1574-6941
pISSN - 0168-6496
DOI - 10.1111/j.1574-6941.2011.01295.x
Subject(s) - rumen , biology , fibrobacter succinogenes , bacteria , cellulase , microbiology and biotechnology , carboxymethyl cellulose , ruminococcus , clostridia , cellulose , food science , triticale , biochemistry , fermentation , botany , chemistry , sodium , genetics , organic chemistry
A method was developed and used to arrest and stain reducing sugars (glucose) produced by bacteria with cell‐surface‐associated carboxymethyl cellulase ( CMC ase) and endoglucanase activities ( CMC bacteria) in the rumen of cows fed alfalfa or triticale. Precipitation of silver oxide on the surface of individual cells was observed using cellulolytic bacterial pure cultures with known CMC ase activity and rumen mixed cultures. The CMC bacteria in the liquid and solid fractions of the rumen digesta were identified using fluorescence in situ hybridization ( FISH ) with currently available and newly designed oligonucleotide probes. The CMC bacteria contributed between 8.2% and 10.1% to the total bacterial cell numbers. Most of the CMC bacteria (75.2–78.5%) could be identified by FISH probing. The known cellulolytic populations R uminococcus flavefaciens , R . albus , and F ibrobacter succinogenes constituted 44.5–53.1% of the total. Other CMC bacteria identified hybridized with the probe C lo549 (11.2–23.0%) targeting members of an uncharacterized genus in C lostridia , the probe I nc852 (8.9–10.7%) targeting members of the family I ncertae S edis III and unclassified C lostridiales , and the probe B ut1243 (< 1%) designed against members of genus B utyrivibrio . Different forage feeds had no marked effects on the percentage abundances of these identified CMC bacteria. All appeared to be involved in cellulose degradation in the rumen of cows fed either alfalfa or triticale.