title: Direct recovery of cyclodextringlycosyltransferase from Bacillus cereus using aqueous two-phase flotation.
abstract: Purification of cyclodextrin glycosyl transferase (CGTase) from Bacillus cereus using polyethylene glycol (PEG)-potassium phosphates aqueous two-phase flotation (ATPF) system was studied in this paper. The effects of varying PEG molecular weight, tie-line length (TLL) value, volume ratio (VR), pH value, crude concentration and gas nitrogen flotation time were investigated. The optimal condition for purification of CGTase was attained at 18.0% (w/w) PEG 8000, 7.0% (w/w) potassium phosphates, VR of 3.0, 20% (w/w) crude load at pH 7, and 80 min nitrogen flotation time at a flow rate of 5 L/min. With this optimal condition, purification factor (PFT) of 21.8 and a yield (YT) of 97.1% were attained. CGTase was successfully purified in a single downstream processing step using the ATPF.
authors.affiliation: Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia.
authors.forename: Yu Kiat
authors.initials: YK
authors.lastname: Lin
authors.affiliation: Manufacturing and Industrial Processes Division, Faculty of Engineering, Centre for Food and Bioproduct Processing, University of Nottingham Malaysia Campus, Jalan Broga, Semenyih 43500, Selangor Darul Ehsan, Malaysia.
authors.forename: Pau Loke
authors.initials: PL
authors.lastname: Show
authors.affiliation: Department of Applied Mathematics, Faculty of Engineering, University of Nottingham Malaysia Campus, Jalan Broga, Semenyih 43500, Selangor Darul Ehsan, Malaysia.
authors.forename: Yee Jiun
authors.initials: YJ
authors.lastname: Yap
authors.affiliation: Department of Food Technology, Faculty of Food Science and Technology, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.
authors.forename: Chin Ping
authors.initials: CP
authors.lastname: Tan
authors.affiliation: School of Chemical Sciences, Universiti Sains Malaysia, Minden 11800, Malaysia.
authors.forename: Eng-Poh
authors.initials: EP
authors.lastname: Ng
authors.affiliation: Institute of Bioscience, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.
authors.forename: Arbakariya B
authors.initials: AB
authors.lastname: Ariff
authors.affiliation: Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia.
authors.forename: Mohamad Suffian B
authors.initials: MS
authors.lastname: Mohamad Annuar
authors.affiliation: Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia. Electronic address: tcling@um.edu.my.
authors.forename: Tau Chuan
authors.initials: TC
authors.lastname: Ling
mesh_terms: D001409:Bacillus cereus / Q000201:enzymology*; D005964:Glucosyltransferases / Q000737:chemistry* / Q000302:isolation & purification* / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D008970:Molecular Weight; D009584:Nitrogen; D010710:Phosphates / Q000737:chemistry; D011092:Polyethylene Glycols / Q000737:chemistry; D017680:Potassium Compounds / Q000737:chemistry; D013997:Time Factors; D014867:Water / Q000737:chemistry*
chemical_list: D010710:Phosphates; D017680:Potassium Compounds; D014867:Water; D011092:Polyethylene Glycols; C013216:potassium phosphate; D005964:Glucosyltransferases; C019963:cyclomaltodextrin glucanotransferase; D009584:Nitrogen
keywords: Aqueous two-phase flotation; Bacillus cereus; Cyclodextringlycosyltransferase; Polyethylene glycol-salt system; Purification