Can someone explain why a bacterium that utilizes carboxymethyl cellulose
(indicated by growth and deep pits in gel medium containing 2.5% high viscosity
sodium salt of CMC and 0.5% agar) comes up negative for cellobiose
utilization (H&L method)? I thought that CMC was broken down from the polymer
to cellobiose to glucose? If so, it seems reasonable that an organism using
CMC should use cellobiose. Where did my logic take a wrong turn?