“…As animal rennet is becoming more scarce and expensive, dairy research workers are showing great interest in finding a suitable substitute (Ritter & Schilt, 1967;Schalinatus & Behnke, 1967;Alais & Novak, 1968). Therefore, it is not surprising that different milk-clotting enzymes from various sources, preferably of microbial origin, are continually being investigated (Tsugo & Yamauchi, 1959 a, b;Dyachenko & Slavyanova, 1962;Srinivasan et al 1962;Singh et al 1967;Ramet, Alais, & Weber 1969). The world literature on this subject is already very large and several reviews in recent years have brought the scientific and technological aspects up to date (Veringa, 1961;Ge'nin, 1968).…”