Inhibition of digestive proteases by vegetable meals in three fish species; seabream (Sparus aurata), tilapia (Oreochromis niloticus) and African sole (Solea senegalensis)

The inhibitory effect of three different vegetable foodstuffs (defatted soy bean meal, corn gluten meal and wheat bran) on alkaline protease activity o f seabream, tilapia and sole was evaluated. Protease inhibition on crude di gestive extracts was assessed using different relative concentrations of pl ant meals and represented by constructing inhibition curves. SDS-PAGE zymog rams were utilised to obtain further details in the characterisation of sen sitivity of some fish enzymes to protease inhibitors. Tilapia showed the gr eatest sensitivity to protease inhibitors present in the assayed meals. A h igh resistance of sole digestive proteases to inhibition produced by soybea n meal or corn gluten meal was detected, although they were sensitive to pr otease inhibitor activity in wheat bran. (C) 1999 Elsevier Science Inc. All rights reserved.