Secondly, the enzymatic deproteinization of shrimp shells by B.
mojavensis A21 crude enzyme was carried out under several experimental conditions, including various enzyme/substrate ratios,
different temperatures, pH and incubation times. Reaction carried
out at 50 ◦C without enzymes resulted in a deproteinization degree
of about 38 ± 2%. Indeed, some proteins associated to chitin by electrostatic forces or hydrogen bonds, could be dissociated by thermal
treatment. However, other proteins are linked to chitin by covalent
bonds, their removal requires severe chemical or enzymatic treatments . The deproteinization rate with an E/S ratio of1 was high
(71 ± 2%), which shows the effectiveness of the enzyme preparation
of B. mojavensis A21, and further increase in enzyme concentration
increased slightly (from 71 ± 2% to 77 ± 2%) the deproteinization
rate. Beyond 20 U/mg the deproteinization rate remained constant.