Bioprocess development for docosahexaenoic acid from novel fungal isolate of Fusarium solani.

Fungal cultures were isolated from soil samples collected from the Western Ghats regions of Kerala. Primary screening of isolated strains were done by Sudan black staining method and 15 lipid producing cultures were isolated. The fatty acid profiling of the positive strains were analyzed for docosahexaenoic acid (DHA) production. Selected oleaginous cultures were grown in submerged culture condition to study the biomass yield and poly unsaturated fatty acid, DHA production. The optimization of production process under submerged conditions was carried out using statistical experimental design and confirmation of DHA was done by GC analysis. Maximum DHA production of 150 mg/l was achieved on 4 days of incubation at submerged condition in the presence of glucose as carbon source.

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.