Effect of soluble carbohydrates on digestion of cellulose by pure cultures of rumen bacteria. [Ruminococcus flavefaciens, R. albus, Bacteroides succinogenes]

Journal Article · Thu Sep 01 04:00:00 EDT 1983 · Appl. Environ. Microbiol.; (United States)

OSTI ID:6771943

Hiltner, P; Dehority, B A

The rate of cellulose digestion in the presence of either glucose or cellobiose was studied for the three predominant species of cellulolytic rumen bacteria: Ruminococcus albus, Ruminococcus flavefaciens, and Bacteroides succinogenes. When a soluble carbohydrate was added to cellulose broth, the lag phase of cellulose digestion was shortened. Presumably, this was due to greater numbers of bacteria, because increasing the size of the inoculum had a similar effect. Cellulose digestion occurred simultaneously with utilization of the soluble carbohydrate. The rate of cellulose digestion slowed markedly for B. succinogenes and R. flavefaciens and slowed less for R. albus after the cellobiose or glucose had been utilized, and was accompanied by a decrease in pH. Both the rate and the extent of cellulose digestion were partially inhibited when the initial pH of the medium was 6.3 or below. R. albus appeared to be less affected by a low-pH medium than were B. succinogenes and R. flavefaciens. When a soluble carbohydrate was added to the fermentation during the maximum-rate phase of cellulose digestion, the rate of cellulose digestion was not affected until after the soluble carbohydrate had been depleted and the pH had decreased markedly. Prolonged exposure of the bacteria to a low pH had little if any effect on their subsequent ability to digest cellulose. Cellulase activity of intact bacterial cells appeared to be constitutive in nature for these three species of rumen bacteria. 30 references.

• Research Organization: Ohio State Univ., Wooster
• OSTI ID: 6771943
• Journal Information: Appl. Environ. Microbiol.; (United States), Journal Name: Appl. Environ. Microbiol.; (United States) Vol. 46:3; ISSN AEMID
• Country of Publication: United States
• Language: English

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59 BASIC BIOLOGICAL SCIENCES
ALDEHYDES
BACTERIA
CARBOHYDRATES
CELLOBIOSE
CELLULASE
CELLULOLYTIC ACTIVITY
CELLULOSE
CHEMICAL REACTIONS
CULTURE MEDIA
DECOMPOSITION
DISACCHARIDES
ENZYMATIC HYDROLYSIS
ENZYME ACTIVITY
ENZYMES
GLUCOSE
GLYCOSYL HYDROLASES
HEXOSES
HYDROLASES
HYDROLYSIS
INHIBITION
LYSIS
MICROORGANISMS
MONOSACCHARIDES
O-GLYCOSYL HYDROLASES
OLIGOSACCHARIDES
ORGANIC COMPOUNDS
PH VALUE
POLYSACCHARIDES
SACCHARIDES
SOLVOLYSIS