A non-purified preparation of intracellular acid phosphatase (EC 220.127.116.11) from a waste mycelium of Aspergillus niger was utilised for dephosphorylation of phytate compounds present in food and feed ingredients. The enzymic hydrolysis of p-nitrophenylphosphate was used for assaying acid phosphatase activity, expressed in standard units (u).
The hydrolysis of phytate phosphorus in wheat bran, soya bean meal and fully formulated feedstuffs for broilers (Galus galus; ‘Cornish’ × White Rock') was carried out at 40°C, a pH value of 4.5 and an enzyme dosage ranging from 12 to 30 u g−1. Complete dephosphorylation of soya bean protein isolates was performed at 60°C, a pH value of 4.5 and an enzyme dosage of 12 u g−1. In the gastrointestinal tract of broilers the in-vivo dephosphorylation of phytates present in feed was observed when the preparation of acid phosphatase was added to the diet.