Immobilization in Nanomatrices of Humicola Lutea Mycelium for Alpha-Galactosidase Biosynthesis in Laboratory Air-Lift Bioreactor

摘要

The sol-gel synthesis of both hybrid nanomatrices containing tetraethylortosilicate (TEOS) as an inorganic precursor and lactic acid, or sepharose as an organic component was made. Crystal as well as surface morphology of the hybrids were investigated using different methods: X-ray diffraction, infrared spectra, BET-analysis and atomic force microscopy (AFM). The obtained nanomatrices were applicated for immobilization of the ???±-galactosidase producing fungal strain Humicola lutea 120?￠????5. The semicontinuous cultivation was carried out in laboratory air-lift bioreactor. Maximal level of enzyme activity (1050?￠????1130 U/l) that was reached in the third to fourth fermentation cycle using TEOS+40% lactic acid was higher than that obtained in the samples with TEOS+20% sepharose (660?￠????770 U/l). The correlation between enzyme productivity and fungal development in the pore structure of the carriers was examined using scanning electron microscopy observation.