Phytase production through response surface methodology and molecular characterization of Aspergillus fumigatus NF191.

Phytase play an important role in phytic acid catalysis that act as a food inhibitor in cereals. Here, we isolated high phytase producing isolates NF191 closely related to Aspergillus fumigatus sp. from piggery soil. DNA was isolated from the fungal culture and amplified the ITS region using ITS1 and ITS4 primer using PCR. The 400-900 bp amplicon was gel eluted and subjected to sequencing. The sequencing results were assembled and compared with NCBI data base which showed the 99% identity of Aspergillus fumigatus. Different carbon sources viz., fructose, galactose, lactose, dextrose, sucrose, maltose and different nitrogen sources (organic & inorganic) NH4Cl, NH4NO3, (NH4)2SO4, KNO3, NaNO3, urea, yeast extract, peptone, beef extract were tested for optimal production. The 0.3% dextrose, 0.5% NH4NO3 and 96 h incubation time showed the best production and enzyme activity at 45 degrees C incubation temperature. The selected parameters, dextrose, ammonium sulphate and incubation time, when employed with statistical optimization approach involving response surface optimization using Box Behnken Design, gave a 1.3 fold increase in phytase production compared to unoptimized condition.

Reduction of phytic acid and enhancement of bioavailable micronutrients in food grains.

More than half of the world populations are affected by micronutrient malnutrition and one third of world's population suffers from anemia and zinc deficiency, particularly in developing countries. Iron and zinc deficiencies are the major health problems worldwide. Phytic acid is the major storage form of phosphorous in cereals, legumes, oil seeds and nuts. Phytic acid is known as a food inhibitor which chelates micronutrient and prevents it to be bioavailabe for monogastric animals, including humans, because they lack enzyme phytase in their digestive tract. Several methods have been developed to reduce the phytic acid content in food and improve the nutritional value of cereal which becomes poor due to such antinutrient. These include genetic improvement as well as several pre-treatment methods such as fermentation, soaking, germination and enzymatic treatment of grains with phytase enzyme. Biofortification of staple crops using modern biotechnological techniques can potentially help in alleviating malnutrition in developing countries.

Phytase production through response surface methodology and molecular characterization of Aspergillus fumigatus NF191.

Phytase play an important role in phytic acid catalysis that act as a food inhibitor in cereals. Here, we isolated high phytase producing isolates NF191 closely related to Aspergillus fumigatus sp. from piggery soil. DNA was isolated from the fungal culture and amplified the ITS region using ITS1 and ITS4 primer using PCR. The 400-900 bp amplicon was gel eluted and subjected to sequencing. The sequencing results were assembled and compared with NCBI data base which showed the 99% identity of Aspergilllus fumigatus. Different carbon sources viz., fructose, galactose, lactose, dextrose, sucrose, maltose and different nitrogen sources (organic & inorganic) NH4Cl, NH4NO3, (NH4)2SO4, KNO3, NaNO3, urea, yeast extract, peptone, beef extract were tested for optimal production. The 0.3% dextrose, 0.5% NH4NO3 and 96 h incubation time showed the best production and enzyme activity at 45 ºC incubation temperature. The selected parameters, dextrose, ammonium sulphate and incubation time, when employed with statistical optimization approach involving response surface optimization using Box Behnken Design, gave a 1.3 fold increase in phytase production compared to unoptimized condition.