Abstract: A cloned chitobiase from a Vibrio parahemolyticus gene cloned into the plasmid pUC18 in E. coli strain DH5.alpha.. The plasmid construct, called pC120, had a 604 kb DNA insert. The recombinant gene expressed chitobiase activity similar to that found in native V. parahemolyticus. In addition to chitobiose, at least six additional substrates were observed to be hydrolyzed by the recombinant chitobiase, including .beta.-N-acetyl galactosamine glycosides, showing that the enzyme is an N-acetyl-hexosaminidase. The enzyme showed resistance to denaturation by 2M NaCl, was thermostable at 45.degree. C., and possessed an unusual range of activity from pH 5 to 9. The enzyme is useful in the degradation of crustacean shells. It catalyzes the production of N-acetyl-glucosamine, a compound which should be valuable as a chiral precursor or intermediate in the synthesis or manufacture of pharmaceutical compounds.

Abstract: Two chitinases from Trichoderma harzianum P1 (ATCC 74058) show chitin-containing-fungus-inhibiting activity. One is an endochitinase and the other is a chitobiase. Both have molecular weights of 40 kDa and isoelectric points of 3.9. Endochitinases and chitobiases including the two purified from Trichoderma harzianum strain P1 demonstrate synergy with each other in anti-fungal effect. Isolated gene encoding for the endochitinase has the sequence set forth in the Sequence Listing as SEQ ID NO:1.