A Comparative Study of Cellulase and Xylanase Activity in Freshwater Crayfish and Marine Prawns

Cellulase and xylanase digestive enzyme activities were compared in four freshwater crayfish (Genus Cherax) and three marine prawn (Genus Penaeus) species.Temperature and pH profiles for cellulase (endoglucanase)were found to be very similar in all species, with maximum activity occurring at 60oC and pH 5.0.Temperature and pH profiles for xylanase (endoxylanase)were also very similar in all cray¢sh species,with maximum activity occurring at 50oC and pH 5.0. Xylanase activity was not detected in the three prawn species examined. In addition, in vitro studies showed thatmost species were able to liberate glucose from carboxymethyl cellulose, indicating that cellulose substrates can be a source of energy for both crayfish and prawn species