Improvements in the production of liquid enzyme solutions

Liquid enzyme solutions containing amylolytic, proteolytic and/or pectolytic enzymes are produced by growing enzyme-producing strains of Bacillus subtilis in an aqueous nutrient medium (see Group VI) and filtering or centrifuging off the bacteria. The enzyme solution is stabilized by adjusting the pH to 7.0, if necessary, adding calcium chloride and phenol or sodium chloride. A solid is produced by spray drying the solution so formed. U.S.A. Specification 2,530,210 is referred to.ALSO:Liquid enzyme solutions containing amylolytic, proteolytic and/or pectolytic enzymes are produced by growing enzyme-producing strains of bacillus subtilis in an aqueous nutrient medium in a deep vessel wherein the nutrient medium comprises carbohydrate and protein or degraded protein without the addition of crushed cereal grain of an amount not exceeding 1 per cent thereof. It is preferred to add iron and manganese salts in the proportions of 20 p.p.m. and 2.5 p.p.m. of the metals respectively. Specified nutrients are malt extract, yeast extract, molasses, cane sugar, invert sugar, glucose, starch, dextrin, starch syrups, corn steep liquor, and aqueous suspension of cooked bran to which soluble phosphates have been added. A preferred medium is a mixture of malt extract and yeast extract, pH adjusted by addition of sodium hydroxide, ammonium hydroxide, sodium bicarbonate, sodium carbonate or calcium carbonate so that after sterilization the pH is 6.3-6.5. Submerged culture with aeration, temperature 28 to 38 DEG C, and preferably 35 DEG C. Amylase added if starch present in medium. Antifoaming agents specified are cetyl alcohol, octadecanol, and polydimethyl siloxane in liquid paraffin. The enzyme solution may be obtained by filtering or centrifuging the fermentation broth, if necessary adjusting the pH to 7.0, and stabilizing the resultant filtrate by the addition of calcium chloride and phenol or 10 to 15 per cent sodium chloride. The solution may be spray dried. U.S.A. Specification 2,530,210 is referred to.