Cellobiose uptake and metabolism by Ruminococcus flavefaciens

Journal Article · Tue Jan 01 04:00:00 EST 1991 · Applied and Environmental Microbiology; (USA)

OSTI ID:5685083

Helaszek, C T; White, B A ^[1]

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1. Univ. of Illinois at Urbana-Champaign (USA)

The cellulolytic ruminal bacterium Ruminococcus flavefaciens FD-1 utilizes cellobiose but not glucose as a substrate for growth. Cellobiose uptake by R. flavefaciens FD-1 was measured under anaerobic conditions (N{sub 2}), using (G-{sup 3}H)cellobiose. The rate of cellobiose uptake for early- or late-log-phase cellobiose-grown cells was 9 nmol/min per mag of whole-cell protein. Cellobiose uptake was inhibited by electron transport inhibitors, iron-reactive compounds, proton ionophores, sulfhydryl inhibitors, N,N-dicyclohexylcarbodiimide, and NaF, as well as lasalocid and monensin. The results support the existence of an active transport system for cellobiose. Transport of (U-{sup 14}C)glucose was not detected with this system. Phosphorylation of cellobiose was not by a phosphoenolpyruvate-dependent system. Cellobiose phosphorylase activity was detected by both a coupled spectrophotometric assay and a discontinuous assay. The enzyme was produced constitutively in cellobiose-grown cells at a specific activity of 329 nmol/min per mg of cell-free extract protein.

• OSTI ID: 5685083
• Journal Information: Applied and Environmental Microbiology; (USA), Journal Name: Applied and Environmental Microbiology; (USA) Vol. 57:1; ISSN 0099-2240; ISSN AEMID
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
CARBOHYDRATES
CARBON 14 COMPOUNDS
CELLOBIOSE
DISACCHARIDES
ENZYMES
HYDROGEN COMPOUNDS
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
METABOLISM
OLIGOSACCHARIDES
ORGANIC COMPOUNDS
SACCHARIDES
TRACER TECHNIQUES
TRITIUM COMPOUNDS
UPTAKE