Microbial degradation of native keratin in batch fermentation
1999
El-Fadaly, H. (Mansoura Univ., El-Mansoura (Egypt). Dept. of Agricultural Microbiology) | Zaied, K.A.
Feather fermentation was carried out using different bacterial strains of the genera Bacillus and Micrococcus and their transconjugants as well. During the time course of fermentation, keratin biodegradation was monitored by measuring both activities of keraitnase and proteinase as well as the content of total free amino acids. Results of the parental strains proved that B. licheniformis CF base 7 was the most producing strain in keratinase and free amino acids after 15 days of fermentation being 206.7 KU/ml and 73.3 Mew g/ml cultural filtrate, respectively. B. subtilis IBF base 6 was in the first in proteinase production giving 148.3 TU/ml cultural filtrate. Experimental data of transconjugants illustrated that all of them gave higher yield than their mid parents after the 3rd day of fermentation. The percent of yield reached to 274, 335, and 269 percent for keratinase, proteinase and free amino acids as well. The same trend of these results was found after calculating the relative increase of these parameters. Values of estimated the correlation coefficient (r) suggesting that the increase in free amino acids is a good indicator for the action of both keratinase and proteinase on keratin.
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