EI-Fadaly,, H., Ibrahim, I., Hamdy, N. (2002). OPTIMIZATION FOR BACTERIAL KERATINASE PRODUCTION IN A LOW COST MEDIUM. Journal of Agricultural Chemistry and Biotechnology, 27(6), 4097-4113. doi: 10.21608/jacb.2002.255575
H. EI-Fadaly,; I. Ibrahim; Naglaa Hamdy. "OPTIMIZATION FOR BACTERIAL KERATINASE PRODUCTION IN A LOW COST MEDIUM". Journal of Agricultural Chemistry and Biotechnology, 27, 6, 2002, 4097-4113. doi: 10.21608/jacb.2002.255575
EI-Fadaly,, H., Ibrahim, I., Hamdy, N. (2002). 'OPTIMIZATION FOR BACTERIAL KERATINASE PRODUCTION IN A LOW COST MEDIUM', Journal of Agricultural Chemistry and Biotechnology, 27(6), pp. 4097-4113. doi: 10.21608/jacb.2002.255575
EI-Fadaly,, H., Ibrahim, I., Hamdy, N. OPTIMIZATION FOR BACTERIAL KERATINASE PRODUCTION IN A LOW COST MEDIUM. Journal of Agricultural Chemistry and Biotechnology, 2002; 27(6): 4097-4113. doi: 10.21608/jacb.2002.255575
OPTIMIZATION FOR BACTERIAL KERATINASE PRODUCTION IN A LOW COST MEDIUM
Dept. Microbiology, Fac. of Agric., Mansoura Univ., Mansoura, Egypt
Abstract
In order to improve the production of bacterial keratinase utilizing the poultry feathers as an environmental waste, some nutritional and environmental factors were considered in a low cost medium. These factors are substrate concentration (chicken feather), '. pH of the cultural medium, growth temperature, inoculum size and agitation effect as well. These experiments were carried out !-Ising two bacterial strains namely Bacillus licheniforrnis CF-26 and Bacillus licheniforrnis PWD-28, Obtained results showed that both tested strains produced the maximum keratlnase with 2% feather as carbon and nitrogen sources after the 9th' day of fermentation. The maximum production of keratinase was found at pH value . of 8.0 for B. licheniforrnis CF-26, while pH 9.0 was the best for B. 1i9heniforrnis PWD-28. For the growth temperature at pH 7.0 of the strains No .. CF-26; the keratinase activity was 3-5 fold higher at 40°C than that obtained at 55·C. At pH 9.0., opposite results were obtained by 1.9 fold. In case of the strain No. PWD-28, the production of keratinase at 40·C was lower at pH 7.5 than its-value. obtained at pH 9.0 by 1.2 fold after the 3'd day of fermentation. The inoculum size of'10% was the optimal for the two tested bacterial strains. In addition, the static cultivation gave higher value of keratinase activity than that of shake culture. The growth· of bacterial strains on chicken feather was also followed by'
. -measuring the activity of proteinase, the total soluble proteins and the obtained free .
amino acids as well. .