ENZYMATIC BACTERIAL DEHAIRING OF BOVINE HIDE BY A LOCALLY ISOLATED STRAIN OF BACILLUS LICHENIFORMIS

摘要

Bacterial isolation and identification were realized for microbial enzymatic dehairing of animal skin. The process was optimized for the required skin quality taking into account the contact time, temperature, pH, crude enzyme concentration (%) as well as mechanical agitation. Scanning electron microscopy (SEM) was used to show the effect of bacterial enzyme on the grain surface and fibres in comparison with the chemical unhairing considering the quality of the skin. The optimization of keratinase activity was also examined. The bacterial isolates were identified as Bacillus licheniformis, (coded as D-10). The experimental results showed that the contact time of 48hr at 35℃, pH8.7, crude enzymatic concentration (v/v) 6% and shaking at 100 rev. min~(-1) are optimal for enzymatic dehairing of animal hide. The results obtained and the SEM results indicate the possibility of using bacterial enzymes to dehair animal skin instead of using chemical compounds, to assure good skin quality, protecting the environment and saving time.