Growth dynamics of isolate 4-2a on medium with cellulose (open symbols, continuous lines), xylan (gray-filled symbols, continuous lines), or a mixture of cellulose and xylan (black-filled symbols, dotted lines). Top, cell biomass concentration (A) and sum of fermentation products (B) (see Fig. 3 for individual products); middle, cellulase (C) and xylanase (D) activity; bottom, pH (E) and intermediate degradation products (F).