Specialty acid protease enzyme for use in propagation and fermentation


SZM AP-1 is a purified native acid protease enzyme that breaks down proteins to yield shorter chain peptides and amino acids. Its application provides yeast nutrients in the form of essential and non-essential amino acids, peptides, and free amino nitrogen. It may also improve access of other hydrolytic enzymes to “bound” starch by breaking down structural proteins.

Typical Characteristics

  • Activity: 150,000 u/mL (minimum)
  • Appearance: Brown liquid
  • pH: 3.0–5.0
  • Bulk Density: 1.15–1.17 g/mL
  • Unit Definition: One unit (u) is the amount of enzyme which hydrolyzes casein protein to 1 μg of tyrosine per 1 minute under the conditions of the assay.

Performance Benefits

SZM AP-1 provides the following benefits to ethanol producers.

  • Higher ethanol yields
  • Enhanced yeast performance
  • Improved corn oil production
  • Lower glycerol concentrations throughout fermentation
  • Higher dosages of SZM AP-1 have shown that the urea/ammonia usage can be reduced by up to 50% due to the increased free amino nitrogen that SZM AP-1 is providing the fermentation

Application Recommendations

SZM AP-1 is used in propagation and/or fermentation in order to provide essential yeast nutrients in the form of amino acids, peptides, and free amino nitrogen. It may also improve access to “bound” starch by breaking down structural proteins. SZM AP-1 has a broad operating range for enhanced process flexibility and performs well within the temperature and pH ranges typical in whole ground corn batch fermentations. In high gravity fermentations, performance can be further enhanced by the addition of SZM XT-20+ Fungal Alpha Amylase.

Dosage Recommendation

SZM AP-1 should be dosed at 0.0030–0.0050% weight enzyme / weight as is corn. The actual dose required will depend upon the conditions of your fermentation: time, initial pH, and the level of solids.

Regulatory Status

  • ISO 9001 registered company
  • Kosher certified
  • GRAS (Generally Recognized as Safe)

GM Status

This product is not a GMO. The enzyme product is manufactured by fermentation of microorganisms that are not present in the final product. The production organisms and the enzyme effectiveness are improved by means of modern technology.


SZM AP-1 is available in totes.


SZM AP-1 will meet the declared activity upon arrival at the plant. SZM AP-1 will meet the declared activity upon arrival at your plant. SZM AP-1 can be safely stored in sealed containers. Enzymes should be stored below 77°F (25°C) and sheltered from direct sunlight for maximum stability.

Shelf Life

The enzymatic activity of SZM AP-1 remains at ≥ 95% for six months when stored at 77°F (25°C). The recommended dosage may need to be increased if stored for longer than six months.

Safety and Enzyme Handling

SZM AP-1 contains proteins obtained from large-scale cultures of a mold. Proteins may cause an allergic-type reaction in sensitized individuals that could require immediate medical attention. Prolonged direct contact may cause minor irritation to skin, eyes, or mucus membranes. For detailed handling information, please refer to the appropriate Safety Data Sheet.

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