title: Response Surface Methodology Modelling of an Aqueous Two-Phase System for Purification of Protease from Penicillium candidum (PCA 1/TT031) under Solid State Fermentation and Its Biochemical Characterization.
abstract: Penicillium candidum(PCA 1/TT031) synthesizes different types of extracellular proteases. The objective of this study is to optimize polyethylene glycol (PEG)/citrate based on an aqueous two-phase system (ATPS) and Response Surface Methodology (RSM) to purify protease fromPenicillium candidum(PCA 1/TT031). The effects of different PEG molecular weights (1500-10,000 g/mol), PEG concentration (9%-20%), concentrations of NaCl (0%-10%) and the citrate buffer (8%-16%) on protease were also studied. The best protease purification could be achieved under the conditions of 9.0% (w/w) PEG 8000, 5.2% NaCl, and 15.9% sodium citrate concentration, which resulted in a one-sided protease partitioning for the bottom phase with a partition coefficient of 0.2, a 6.8-fold protease purification factor, and a yield of 93%. The response surface models displayed a significant (p≤ 0.05) response which was fit for the variables that were studied as well as a high coefficient of determination (R²). Similarly, the predicted and observed values displayed no significant (p> 0.05) differences. In addition, our enzyme characterization study revealed thatPenicillium candidum(PCA 1/TT031) produced a slight neutral protease with a molecular weight between 100 and 140 kDa. The optimal activity of the purified enzyme occurred at a pH of 6.0 and at a temperature of 50°C. The stability between different pH and temperature ranges along with the effect of chemical metal ions and inhibitors were also studied. Our results reveal that the purified enzyme could be used in the dairy industry such as in accelerated cheese ripening.
authors.affiliation: Faculty of Food Science and Technology, University Putra Malaysia, 43400 UPM Serdang, Selangor Darul Ehsan, Malaysia. amaalalhelli@yahoo.com.|Institute of technology, Middle technical University, 29008 Alzafaranya, Baghdad, Iraq. amaalalhelli@yahoo.com.
authors.forename: Amaal M
authors.initials: AM
authors.lastname: Alhelli
authors.affiliation: Faculty of Food Science and Technology, University Putra Malaysia, 43400 UPM Serdang, Selangor Darul Ehsan, Malaysia. myazid@upm.edu.my.|Halal Products Research Institute, University Putra Malaysia, 43400 UPM Serdang, Selangor Darul Ehsan, Malaysia. myazid@upm.edu.my.
authors.forename: Mohd Yazid
authors.initials: MY
authors.lastname: Abdul Manap
authors.affiliation: Faculty of Food Science and Technology, University Putra Malaysia, 43400 UPM Serdang, Selangor Darul Ehsan, Malaysia. karimsabo@upm.edu.my.
authors.forename: Abdulkarim Sabo
authors.initials: AS
authors.lastname: Mohammed
authors.affiliation: Faculty of Food Science and Technology, University Putra Malaysia, 43400 UPM Serdang, Selangor Darul Ehsan, Malaysia. hamedmi@upm.edu.my.
authors.forename: Hamed
authors.initials: H
authors.lastname: Mirhosseini
authors.affiliation: Faculty of Food Science and Technology, University Putra Malaysia, 43400 UPM Serdang, Selangor Darul Ehsan, Malaysia. eilafsuliman@gmail.com.
authors.forename: Eilaf
authors.initials: E
authors.lastname: Suliman
authors.affiliation: Faculty of Food Science and Technology, University Putra Malaysia, 43400 UPM Serdang, Selangor Darul Ehsan, Malaysia. mojgan.shad@gmail.com.
authors.forename: Zahra
authors.initials: Z
authors.lastname: Shad
authors.affiliation: Faculty of Food Science and Technology, University Putra Malaysia, 43400 UPM Serdang, Selangor Darul Ehsan, Malaysia. nameermohammed5@gmail.com.
authors.forename: Nameer Khairulla
authors.initials: NK
authors.lastname: Mohammed
authors.affiliation: Faculty of Food Science and Technology, University Putra Malaysia, 43400 UPM Serdang, Selangor Darul Ehsan, Malaysia. shobirin@upm.edu.my.|Halal Products Research Institute, University Putra Malaysia, 43400 UPM Serdang, Selangor Darul Ehsan, Malaysia. shobirin@upm.edu.my.
authors.forename: Anis Shobirin
authors.initials: AS
authors.lastname: Meor Hussin
mesh_terms: D011232:Chemical Precipitation; D004795:Enzyme Stability; D005285:Fermentation; D005656:Fungal Proteins / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000302:isolation & purification*; D006863:Hydrogen-Ion Concentration; D059625:Liquid-Liquid Extraction; D010407:Penicillium / Q000201:enzymology*; D010447:Peptide Hydrolases / Q000737:chemistry / Q000302:isolation & purification*; D011092:Polyethylene Glycols / Q000737:chemistry; D011480:Protease Inhibitors / Q000737:chemistry
chemical_list: D005656:Fungal Proteins; D011480:Protease Inhibitors; D011092:Polyethylene Glycols; D010447:Peptide Hydrolases
keywords: Penicillium candidum; RSM; aqueous two phase systems; protease; solid state fermentation