Protease from Bacillus sp ATP-P5 was produced and purified by using ammonium sulphate precipitation and anion exchange chromatography with 1.9 fold of purification. The purified enzyme showed a single band on SDS-PAGE and it was determined as 29 KDa. The purified enzyme was used for silver recovery from used X-Ray film. Silver is a very precious metal used in various purposes such as photographic films, X-Ray, jewelleries and some electronic items. Alkaline protease successfully striped and recovered silver in good yield from the used photographic films. The used X-Ray film contains 1.5-2% (w/w) metallic silver (Black in color) which can be recovered and reused. The purified protease was then immobilized by entrapment method using Ca-Alginate beads. The optimum immobilization conditions such as pH, temperature and incubation time were investigated. After immobilization the pH stability of the protease was improved and there was no change in optimum temperature after immobilization.
Bacillus, Immobilization, X-Ray film, Silver recovery, Ca-Alginate
Share This Article
© The Author(s) 2015. Open Access. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License which permits unrestricted use, sharing, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.