Organic Acids Associated with Saccharification of Cellulosic Wastes During Solid-State Fermentation
2011
El-Naggar, Noura El-Ahmady, Mubarak City for Scientific Research and Technology Applications, Alexandria, Egypt | El-Hersh, Mohammed Saad, Water and Environment Research Institute, Agricultural Research Center, Giza, Egypt
Saccharification of five cellulosic wastes, i.e. rice husks, wheat bran, corn cobs, wheat straw and rice straw by three cellulytic fungi, i.e. Aspergillus glaucirs MN1, Aspergillus oryzae MN2 and Penicillium purpurogenum MN3, during solid-state fermentation (SSF) was laboratory studied. Rice husks, wheat bran, and corn cobs were selected as inducers of glucose production in the tested fungi. An incubation interval of 10 days was optimal for glucose production. Maximal activities of the cellulases FP-ase, CMC-ase, and β-glucosidase were detected during SSF of rice husks by P. purpurogenum; however, α-amylase activity (7.2 U/g) was comparatively reduced. Meanwhile, the productivities of FP-ase, CMC-ase, and β-glucosidase were high during SSF of rice husks by A. glaucus; however, they decreased during SSF of corn cobs by P. purpurogenum. Addition of rock phosphate (RP) (75 mg P₂O∧5) decreased the pH of SSF media. (NH₄)₂SO₄ was found to be less inducer of cellulytic enzymes, during, SSF of rice husks by A. glaucus or A. oryzae; it also induced phytase production and solubilization of RP. The organic acids associated with saccharification of the wastes studied have also been investigated. The highest concentration of levulinic acid was detected (46.15 mg/g) during SSF of corn cobs by P. purpurogenum. Likewise, oxalic acid concentration was 43.20 mg/g during SSF of rice husks by P. purpurogenum.
Mostrar más [+] Menos [-]Palabras clave de AGROVOC
Información bibliográfica
Este registro bibliográfico ha sido proporcionado por Korea Agricultural Science Digital Library