Section 173.150 - Milk-clotting enzymes, microbialMilk-clotting enzyme produced by pure-culture fermentation process may be safely used in the production of cheese in accordance with the following prescribed conditions:
(a) Milk-clotting enzyme is derived from one of the following organisms by a pure-culture fermentation process: (1)Endothia parasitica classified as follows: Class, Ascomycetes; order, Sphaeriales; family, Diaporthacesae; genus, Endothia; species, parasitica.(2)Bacillus cereus classified as follows: Class, Schizomycetes; order, Eubacteriales; family, Bacillaceae; genus, Bacillus; species, cereus (Frankland and Frankland).(3)Mucor pusillus Lindt classified as follows: Class, Phycomycetes; subclass, Zygomycetes; order, Mucorales; family, Mucoraceae; genus, Mucor; species, pusillus; variety, Lindt.(4)Mucor miehei Cooney et Emerson classified as follows: Class, Phycomycetes; subclass, Zygomycetes; order, Mucorales; family, Mucoraceae; genus, Mucor; species, miehei; variety, Cooney et Emerson.(5)Aspergillus oryzae modified by recombinant deoxyribonucleic (DNA) techniques to contain the gene coding for aspartic proteinase from Rhizomucor miehei var. Cooney et Emerson as defined in paragraph (a)(4) of this section, and classified as follows: Class, Blastodeuteromycetes (Hyphomycetes); order, Phialidales (Moniliales); genus, Aspergillus; species oryzae.(b) The strains of organism identified in paragraph (a) of this section are nonpathogenic and nontoxic in man or other animals.(c) The additive is produced by a process that completely removes the generating organism from the milk-clotting enzyme product.(d) The additive is used in an amount not in excess of the minimum required to produce its intended effect in the production of those cheeses for which it is permitted by standards of identity established pursuant to section 401 of the Act.42 FR 14526, Mar. 15, 1977; 42 FR 56728, Oct. 28, 1977, as amended at 62 FR 59284, Nov. 3, 1997