Arylsulphatase activity in milk and rennet from different sources

Abstract

Abstract Arylsulphatase activity on two substrates, p -nitrocatechol sulphate ( p NCS) and p -nitrophenyl sulphate ( p NPS), in milk and commercial rennet from different sources was measured. Cows’ and sheep's milk contained arylsulphatase active on p NCS, and batch pasteurization reduced the activity. Rennets from animal sources, including calf, kid and lamb, exhibited arylsulphatase activity with different substrate specificities. A fermentation-produced chymosin from a genetically engineered microorganism did not exhibit detectable arylsulphatase activity. A commercial rennet paste showed arylsulphatase activity after dialysis.