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Immobilization of Bacillus circulans MTCC 7906 for enhanced production of alkaline protease under batch and packed bed fermentation conditions

2009; Volume: 7; Issue: 2 Linguagem: Inglês

10.5580/2599

1937-8289

Probiotics and Fermented Foods

Alkaline protease production by immobilized cells of Bacillus circulans MTCC 7906 was studied using agar-agar and calcium alginate as entrapment materials. Under batch conditions using agar agar, 2% agar concentration, 6.25mm bead size and 200 beads/ flask inoculum size were the optimal conditions for a maximum alkaline protease production of 19.9 IU/ml and while for alginate beads, 3% alginate concentration, 5.2mm bead size and 200 beads/ flask inoculum size were the optimal conditions for a maximum alkaline protease production of 19.7 IU/ml. The alginate and agar agar beads were reusable for four and nine successive batch cycles respectively. A maximum enzyme production of 28 and 27 IU/ml was obtained with incubation time of 36 h, column length of 30cm and flow rate of 10ml/h with agar-agar and alginate entrapped cells respectively under packed bed fermentation conditions. Scanning electron microscopy (SEM) of the agar agar entrapped cells showed a random distribution of cells on the surface with pockets of high cell density.