The anaerobic cellulolytic organism, Ruminococcus flavefaciens, readily utilizes cellobiose but most strains fail to ferment glucose. This poses a question as to the mechanism of cellulose dissimilation by the organism. It seems probable that cellulose digestion first proceeds by the release of units of cellobiose by the catalytic action of a cellulase (Ayers, 1958). Following this, there is th...

The cellobiose catabolic system of Escherichia coli K12 is being used to study the role of cryptic genes in evolution of new functions. Escherichia coli does not use beta-glucoside sugars; however, mutations in several loci can activate the cryptic bgl operon and permit growth on the beta-glucoside sugars arbutin and salicin. Such Bgl+ mutants do not use cellobiose, which is the most common bet...

Streptomyces reticuli has an inducible ATP-dependent uptake system specific for cellobiose and cellotriose. By reversed genetics a gene cluster encoding components of a binding protein-dependent cellobiose and cellotriose ABC transporter was cloned and sequenced. The deduced gene products comprise a regulatory protein (CebR), a cellobiose binding lipoprotein (CebE), two integral membrane protei...

When glucose or cellobiose was provided as an energy source for Fibrobacter succinogenes, there was a transient accumulation (as much as 0.4 mM hexose equivalent) of cellobiose or cellotriose, respectively, in the growth medium. Nongrowing cell suspensions converted cellobiose to cellotriose and longer-chain cellodextrins, and in this case the total cellodextrin concentration was as much as 20 ...

The rumen bacterium Cellulosilyticum ruminicola H1 efficiently hydrolyzes cellulose. To gain insights into the regulatory mechanisms of cellulase synthesis, comparative transcriptome analysis was conducted for cultures grown on 2% filter paper, 0.5 and 0.05% cellobiose, and 0.5% birchwood xylan. It was found that cellulose induced a majority of (hemi)cellulases, including 33 cellulases and a ce...

Molecular motions of polycrystalline cellobiose have been investigated by measuring proton spin-lattice relaxation times, T1 and T1rho, and the second moment, M2, in both protonated and D2O exchanged forms over the temperature range 120-380 K. T1 relaxation is dominated by the motions of hydroxyl groups between 150 and 380 K, characterised by an activation energy of about 8.74 kJ/mol, whereas T...