Enzymatic hydrolysis of pangasius belly protein by-product using for Bacillus subtilis cultivation

Abstract

Through the process of studying the Pangasius belly hydrolysate by neutrase enzyme, the belly Pangasius was defated; it showed a kinetic index Vmax = 1.283 μmol tyrosine per minute, Km = 0.377 g protein with reliability R2 = 0.997, enzyme/substrate ratio (E/S) (0.652 mg enzyme/0.975 g protein). Hydrolysis efficiency of tyrosine according to enzyme/substrate 42.69%, ortho-phthaldialdehyde efficiency of the enzyme/substrate was 52.51% at 240 minutes. Subsequently, the belly Pangasius protein hydrolysate was dry-sprayed at 180°C. After drying, the moisture and water activity of dried fish protein hydrolysates were 6.05% and 0.55, respectively. Both commercial peptone and protein hydrolysate from Pangasius belly were used as nitrogen components for Bacillus subtilis growth media at the time from 0 to 72 hours at 37oC and pH = 7, then the powder medium hydrolysed by enzyme neutrase was higher than the commercial peptone medium. In addition, the result from the activity of enzyme protease in the two media for at time of 4, 8, 12, 16, 20, 24 hours, at 37oC and pH = 7 showed that the activity of protease in hydrolysed protein medium from the belly Pangasius was similar to commercial peptone.