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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
1997-7-18
pubmed:abstractText
The survival of Bacteroides thetaiotaomicron strain BTX under rumen-simulating conditions was studied. Strain BTX is a recombinant variant of strain 5482 engineered for the production of high levels of xylanase, an enzyme important in the degradation of hemicellulose. Strain BTX was not inhibited by compounds present in rumen fluid and it grew well in media containing rumen fluid (up to 75%) or high concentrations of volatile fatty acids (total concentration, 100 mmol l-1). The ability of strain BTX to compete with other microorganisms under rumen-like conditions was studied in in vitro incubations of rumen contents. These experiments employed a consecutive batch culture (CBC) system consisting of alfalfa suspended in a rum flid buffer inoculated with blended rumen contents and maintained by transfers (10%, v/v) at 48 h intervals. CBC cultures contained a diversity of microbial morphotypes and accumulated fermentation products in rumen-like proportions. WHen added alone, the numbers of BTX cells were maintained for only a few hours, and then declined precipitously until undetectable after 48 h. If CBC cultures were also supplemented with chondroitin sulphate (a mucopolysaccharide used by Bact. thetaiotaomicron), strain BTX grew and the pattern of its population generally followed that of the total population of ruminal bacteria in these cultures. When transferred into fresh CBC cultures containing chondroitin sulphate, BTX was again able to grow and increase in numbers, but to a diminished degree. Although BTX was able to survive and maintain itself in chondroitin sulphate supplemented cultures, this was at a very low level (10(5) ml-1). The potential for manipulation of rumen function by inoculation with recombinant bacteria is discussed.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
1364-5072
pubmed:author
pubmed:issnType
Print
pubmed:volume
82
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
743-50
pubmed:dateRevised
2003-11-14
pubmed:meshHeading
pubmed:year
1997
pubmed:articleTitle
Survival of the recombinant Bacteroides thetaiotaomicron strain BTX in in vitro rumen incubations.
pubmed:affiliation
Fermentation Biochemistry Unit, National Centre for Agricultural Utilization Research, USDA, Peoria, IL 61604, USA. cottama@ncaurl.ncaur.gov
pubmed:publicationType
Journal Article