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Production of Microbial Food Enzymes from Bacillus Subtilis and Use of Uf and Freeze-drying for Separation and Concentration

出版	Universiti Pertanian Malaysia, 1993
URL	http://books.google.com.hk/books?id=H5ugAQAACAAJ&hl=&source=gbs_api

註釋Membrane separation process (ultrafiltration) was used in this study for separation and concentration of ( -amylase from a crude extract of enzymes produced by B. subtilis. Alpha-amylase recovered in the ultrafiltration was concentrated and then freeze-dried. The maximum separation was observed while using membrane with molecular weight cut-off of 50,000 (Amicon, XM 50) at 40 C and 15 psi pressure. Recovery at this stage was 54.5% with a purification factor of 1.9 fold. Membrane with molecular weight cut-off of 10,000 (PM 10) was used to concentrate the ultrafiltrate using temperature 40 C and pressure 25 psi. Freeze-drying was used to concentrate the -amylase enzyme at 60 C for 10hrs to get the dried powder form of enzyme. Final product showed a specific activity of 75.5 units/mg protein or 349 units/mg solid with a net recovery of 43.9%. Authors are grateful to Malaysian Sugar Manufacturing Company Berhad for funding this project. [Authors' abstract].