PRODUCTION OF LIPASES IN SOLID-STATE FERMENTATION BY Aspergillus niger F7-02 WITH AGRICULTURAL RESIDUES

Abstract

In this study mould strains screened and molecularly identified as Aspergillus niger F7-02 was used to produced extracellular lipase in Solid State Fermentation (SSF) process. Different agricultural residues were combined in different ratios as carbon, nitrogen and elemental sources in the solid culture medium. The optimization of the culture medium was carried out for such parameters as incubation time (24 h - 96 h), inoculum concentration (0.5 – 3.0%, w/v), initial moisture content (40 – 70%, w/v), and initial pH (6 – 8) for maximum yield. The maximum lipase activity of 76.7 U/ml was obtained with a medium containing rice bran (RB), palm kernel cake (PKC), groundnut cake (GNC) and starch (S) at the ratio of 5:5:3:1 (%w/w) with optimum conditions of 60% moisture, 1% inoculum and a pH of 7.0 with an incubation temperature of 30 oC and incubation time of 72 h.