Resumo

MRUDULA, Soma  e  SHYAM, Nidhi. Immobilization of Bacillus megaterium MTCC 2444 by Ca-alginate entrapment method for enhanced alkaline protease production. Braz. arch. biol. technol. [online]. 2012, vol.55, n.1, pp. 135-144. ISSN 1516-8913.  http://dx.doi.org/10.1590/S1516-89132012000100017.

Optimization of culture conditions and immobilization parameters for alkaline protease production was carried out by employing Bacillus megaterium MTCC2444. The partially purified enzyme was tested for its stability in the presence of oxidants, surfactants and commercial detergents. The optimum temperature, pH, incubation time and inoculum size were 55 ºC, 11, 48 h, 1 %, respectively. Calcium alginate was used as the immobilization matrix and the effects of gel concentration, bead size, age of immobilized cells, solidification period and initial biomass concentration on alkaline protease production and cell leakage were investigated. The results indicated that the immobilization was most effective with 4 % gel concentration, bead size of 3 mm, 24 h aged immobilized cells for a solidification period of 12 h at 1.5 % initial biomass concentration. The enzyme showed good stability in the presence of oxidants, surfactants and commercial detergents.

Palavras-chave : optimization; immobilized cells; cell leakage; detergent; oxidant stability.