Pengoptimuman penghasaan dan penulenanenzdd keratinase daripada microsporum gypseum s(f)23 pencilan temp a tan menggunakan fermentasi kultur tenggelam

Loading...
Thumbnail Image
Date
2009-07
Authors
Zainul Kamal, Syazni
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Chicken feathers which consist 90% keratin are produce as a waste by poultry processing industries in huge quantities every year. So, this research was developed to produce keratinase that are able to degrade keratin into protein and amino acid to be use in poultry dietary. The isolate that was used in the production of keratinase was identified as Microsporum gypseum. The isolate was isolated using a baiting technique from soil sample from a horse stable located in Georgetown, Pulau Pinang. Microsporum gypseum S(F)23 achieved maximum extracellular keratinase activity after 6 days of incubation. Optimization of cultural conditions and medium compositions showed an increment of 287.6% or 0.903 U/ml compared with the activity before optimization which was 0.233 U/ml. The optimum cultural conditions were agitation speed of 150 rpm, initial pH medium of 8.0, incubation temperature of 30°C and inoculum size 15% (v/v) l.Oxl05 spores per ml. Meanwhile, optimal medium composition were (w/v) ground chicken feathers, 1 %; NaCl, 0.05%; KH2P04, 0.04%; K2HP04, 0.03% and peptone, 0.5%. Keratinase is an inducible enzyme and only produced by Microsporum gypseum S(F)23 culture in the presence of keratin substrate, which are chicken feathers. The presence of glucose in the culture medium at low concentration inhibits keratinase activity. Keratinase was purified from the culture broth by ultrafiltration (Amicon Centricon 3 kDa system) and Sephadex G-75 gel filtration chromatography, twice. Peak was purified about 7.411 fold with a yield of 0.831% and specific activity of 0. 704 U/mg protein. Its molecular weight was estimated to be around 27 000 Dalton by SDS-P AGE. Some of the biochemical characteristics were identified. The purified keratinase had the optimum pH of8.0 and stable at pH range of8.0 to 9.0 and retained 100% activity after 2 hours. While optimum temperature for purified keratinase was 40°C and stable at temperature range from 37°C to 40°C and retained more than 80% activity after 2 hours. Furthermore, 1 mM of Ca2+ and Na2+ were found to activate keratinase activity while 1 mM of Mi+, Zn2+, Hg+, Ba2+, Co2+, K+, Pb2+, Cd2+ and EDTA inhibited keratinase activity. Keratinase had broad substrate specification and active towards soluble proteins and insoluble proteins.
Description
Keywords
Penulenan enzim keratinase , Microsporum gypseum S(F)23 , Menggunakan fermentasi kultur tenggelam
Citation