[Production and properties of the milk-clotting enzyme]. / Producción y propiedades de la enzima coagulante de leche.

Milk-clotting enzyme from a strain of Mucor varians Pispek selected in a previous work was obtained by solid culture followed by water extraction. Moistened wheat bran (120% water on dry bases) proved to be a good medium for the production of the milk-clotting enzyme. The production may be related to growth and 4,000 U milk-clotting activity by g of wheat bran was achieved. The milk-clotting enzyme was easily extracted with water from the cultures and could be precipitated by salting out with ammonium sulfate or by mixing with ethanol, methanol or acetone. The crude enzyme is an acid protease having optimal activity at pH: 3.0. Like calf rennet, this crude enzyme from M. varians loses activity with heat treatment. The level of lipolytic activity of the crude enzyme is similar to some commercial preparations and neither an antibiotic nor an amylase activity was demonstrated in the crude extracts.

Produccion y propiedades de la enzima coagulante de leche. / Produccion and properties of milk-clotting enzyme

Se obtuvieron enzimas coagulantes de leche en cultivo en sustrato solido con una cepa de Mucor varians Pispek, previamente seleccionada. El afrecho de trigo humedecido (120% de agua sobre base seca) demostro ser un buen medio de produccion, alcanzando niveles de 4.000 U de actividad coagulante de leche por g de afrecho. La enzima fue extraida de los cultivos con agua y precipitada con sulfato de amonio o con solventes como etanol, metanol o acetona.La enzima cruda es una proteasa acida con actividad optima a pH 3,0. Como la quimiosina de ternero, esta enzima cruda de M.varians pierde actividad con el tratamiento termico. El nivel de actividad lipolitica de la enzima cruda es similar al de algunas preparaciones comerciales y no se demostro actividad antibiotica, ni amilolitica en los extractos crudos

Produccion y propiedades de la enzima coagulante de leche. / Produccion and properties of milk-clotting enzyme

Se obtuvieron enzimas coagulantes de leche en cultivo en sustrato solido con una cepa de Mucor varians Pispek, previamente seleccionada. El afrecho de trigo humedecido (120% de agua sobre base seca) demostro ser un buen medio de produccion, alcanzando niveles de 4.000 U de actividad coagulante de leche por g de afrecho. La enzima fue extraida de los cultivos con agua y precipitada con sulfato de amonio o con solventes como etanol, metanol o acetona.La enzima cruda es una proteasa acida con actividad optima a pH 3,0. Como la quimiosina de ternero, esta enzima cruda de M.varians pierde actividad con el tratamiento termico. El nivel de actividad lipolitica de la enzima cruda es similar al de algunas preparaciones comerciales y no se demostro actividad antibiotica, ni amilolitica en los extractos crudos

Producción y propiedades de la enzima coagulante de leche. / [Production and properties of the milk-clotting enzyme]

Milk-clotting enzyme from a strain of Mucor varians Pispek selected in a previous work was obtained by solid culture followed by water extraction. Moistened wheat bran (120

water on dry bases) proved to be a good medium for the production of the milk-clotting enzyme. The production may be related to growth and 4,000 U milk-clotting activity by g of wheat bran was achieved. The milk-clotting enzyme was easily extracted with water from the cultures and could be precipitated by salting out with ammonium sulfate or by mixing with ethanol, methanol or acetone. The crude enzyme is an acid protease having optimal activity at pH: 3.0. Like calf rennet, this crude enzyme from M. varians loses activity with heat treatment. The level of lipolytic activity of the crude enzyme is similar to some commercial preparations and neither an antibiotic nor an amylase activity was demonstrated in the crude extracts.

[Production of a concentrate of Mucor bacilliformis acid protease]. / Produccion de un concentrado de proteasa ácida de Mucor bacilliformis.

A concentrate of milk-clotting enzyme was produced by culture of Mucor bacilliformis on wheat bran medium moistened to 120% water on dry bases with HC1 2 N solution. The wheat bran was autoclaved, spread on trays and inoculated with 5.10(6) spore/gr of dry bran. After 10 days of culture at 21 degrees C, the enzyme produced was extracted with water and adjusted to pH 4.4. The precipitation was performed with ethanol. The precipitate was dissolved in HCl solution (pH 4.5) and it was concentrated by dialysis against polyethylene glycol 20.000. The enzyme solution had a specific activity of 1123 units/mg. and it was tested in the elaboration of cream cheese.

Produccion de un concentrado de proteasa acida de Mucor bacilliformis. / Production of an acid protease concentrate from Mucor bacilliformis

Se obtuvo un concentrado de enzimas congulantes de leche por cultivo de Mucor bacilliformis en afrecho de trigo humectado a 120% de agua sobre base seca con solucion de HC1 0,2 N. El afrecho esterilizado fue dispuesto en bandejas, e inoculado con 5.10 (6) esporos/gr de afrecho seco. Luego de 10 dias de incubacion se extrajo el afrecho enmohecido con agua, se ajusto el pH a 4,4 y se precipito el sobrenadante limpido con etanol. El precipitado fue disuelto en agua clorhidrica (pH 4,5) y concentrado por dialisis contra polietilenglicol 20000. La solucion con una actividad especifica de 1128 U/mg, se utilizo en dos ensayos de elaboracion de queso tipo cremoso

Produccion de un concentrado de proteasa acida de Mucor bacilliformis. / Production of an acid protease concentrate from Mucor bacilliformis

Se obtuvo un concentrado de enzimas congulantes de leche por cultivo de Mucor bacilliformis en afrecho de trigo humectado a 120% de agua sobre base seca con solucion de HC1 0,2 N. El afrecho esterilizado fue dispuesto en bandejas, e inoculado con 5.10 (6) esporos/gr de afrecho seco. Luego de 10 dias de incubacion se extrajo el afrecho enmohecido con agua, se ajusto el pH a 4,4 y se precipito el sobrenadante limpido con etanol. El precipitado fue disuelto en agua clorhidrica (pH 4,5) y concentrado por dialisis contra polietilenglicol 20000. La solucion con una actividad especifica de 1128 U/mg, se utilizo en dos ensayos de elaboracion de queso tipo cremoso

Produccion de un concentrado de proteasa ácida de Mucor bacilliformis. / [Production of a concentrate of Mucor bacilliformis acid protease]

A concentrate of milk-clotting enzyme was produced by culture of Mucor bacilliformis on wheat bran medium moistened to 120

water on dry bases with HC1 2 N solution. The wheat bran was autoclaved, spread on trays and inoculated with 5.10(6) spore/gr of dry bran. After 10 days of culture at 21 degrees C, the enzyme produced was extracted with water and adjusted to pH 4.4. The precipitation was performed with ethanol. The precipitate was dissolved in HCl solution (pH 4.5) and it was concentrated by dialysis against polyethylene glycol 20.000. The enzyme solution had a specific activity of 1123 units/mg. and it was tested in the elaboration of cream cheese.