Date wastes as substrate for the production of α-amylase and invertase

In Algeria the date wastes production is estimated to be 85.000 tons. Date wastes are an economical source of carbohydrates for conversion to industrial enzymes because it is readily available and relatively low priced. The aim of the present study was to investigate the potential of using date wastes as a substrate for the production of α-amylase and invertase. Thirty strains of A. niger were isolated from the saline soils collected from five arid locations in Algeria. The process parameters; time, temperature, sugar content, initial pH, nitrogen source, nitrogen and phosphorus content, on the production of these enzymes were optimized. The obtained results show that the strain of Aspergillus niger ANSS-B5 produced the highest level of these enzymes. For α-amylase production, the cumulative effect of fermentation period of 96 h, temperature of 30°C, sugar content of 20 g/L, initial pH=5.5, supplemented with yeast extract as nitrogen source, and yeast extract and potassium phosphate at 5.0 g/L, content during the fermentation process of date wastes syrup produced α-amylase levels up to 285.6 U/ml. Invertase to 195.56 U/ml were produced under optimum conditions of 96h, temperature of 30°C, initial pH=6.0, sugars content of 40.0 g/L and utilisation of yeast extract and potassium phosphate at concentrations of 11.0 and 3.5 g/L, respectively. It is concluded from these results, using date wastes product as carbon source is very interesting for industrial scale application for the production of these enzymes.