Production of Beluga Whale (Delphinapterus leucas) Chymosin in the Methylotrophic Yeast Komagataella phaffii and Characteristics of the Recombinant Enzyme

A producer strain of Komagataella phaffii of recombinant beluga whale (Delphinapterus leucas) chymosin with a productivity of 80 mg/L was obtained, and the physico-chemical properties of the enzyme were studied for possible use in the food industry. The specific activity of the recombinant beluga chymosin was 55 IMCU/mg, which is significantly lower than that of recombinant bovine chymosin. The beluga whale chymosin has a high nonspecific proteolytic activity, which impaired its properties and ruled out its used in the food industry. Apparently, the amino acid substitutions K221M and K294Q are critically important and lead to a lower binding of casein micelles to the recombinant chymosin of the beluga whale.