HYDROLYSIS OF CELLULOSE USING TERNARY MIXTURES OF PURIFIED CELLULOSES

The saccharification of microcrystalline cellulose by reconstituted te rnary mixtures of purified cellulases (one endoglucanase and two cello biohydrolases) has been studied over the entire range of mixture compo sitions. Ternary plots are used to compare the performance of five syn thetic mixtures drawn from the cellulase systems of Acidothermus cellu lolyticus, Trichoderma reesei, Thermomonospora fusca, and Thermotoga n eapolitana. Results reveal that at least one synthetic mixture utilizi ng enzymes from three different organisms delivers performance competi tive with that of a ''native'' (i.e., co-evolved) ternary system drawn exclusively from T. reesei. This heterologous system, consisting of t he endoglucanase El from A. cellulolyticus and the exoglucanases CBHI from T, ressei and E-3 from T, fusca, is forgiving from the system-des ign point of view, in that it delivers high saccharification rates ove r a wide range of mixture compositions.