title: Potentiometric biosensor for determination of urea in milk using immobilized Arthrobacter creatinolyticus urease.
abstract: The extracellular urease from Arthrobacter creatinolyticus was partially purified by ammonium sulfate precipitation and immobilized on PAN [poly(acrylonitrile-methylmethacrylate-sodium vinylsulfonate)] membrane. The urease immobilized PAN membrane exhibited an activity of 97.92U/cm(2) under the optimum conditions of 1.0% enzyme concentration, 15% glutaraldehyde, 24h immobilization time and temperature of 4°C. The changes in surface morphology of the membrane after immobilization were studied by SEM and ATR-FTIR analysis. Immobilized membrane was associated with potentiometric electrode for calibration of biosensor and the results showed a linear response for wide range of urea concentration from 1 to 100mM. The immobilized urease had good storage stability for a period of 70days at 4°C and could be effectively reused for 13cycles. Urease immobilized membrane was also employed in analysis of urea spiked milk samples.
authors: Department of Biotechnology, Central Leather Research Institute, Adyar, Chennai, Tamil Nadu 600020, India.
authors: Rajendran
authors: R
authors: Ramesh
authors: Department of Biotechnology, Central Leather Research Institute, Adyar, Chennai, Tamil Nadu 600020, India.
authors: Puhazhselvan
authors: P
authors: Puhazhendi
authors: Nuclear Agriculture and Biotechnology Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085, India.
authors: Jitendra
authors: J
authors: Kumar
authors: Department of Biotechnology, Central Leather Research Institute, Adyar, Chennai, Tamil Nadu 600020, India.
authors: Marichetti Kuppuswami
authors: MK
authors: Gowthaman
authors: Nuclear Agriculture and Biotechnology Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085, India.
authors: Stanislaus Francis
authors: SF
authors: D'Souza
authors: Department of Biotechnology, Central Leather Research Institute, Adyar, Chennai, Tamil Nadu 600020, India. Electronic address: nrkamini@rediffmail.com.
authors: Numbi Ramudu
authors: NR
authors: Kamini
mesh_terms: D000181:Acrylonitrile / Q000737:chemistry; D000818:Animals; D001173:Arthrobacter / Q000737:chemistry*; D015374:Biosensing Techniques / Q000379:methods; D004566:Electrodes; D004800:Enzymes, Immobilized / Q000737:chemistry*; D005976:Glutaral / Q000737:chemistry; D020366:Methylmethacrylate / Q000737:chemistry; D008892:Milk / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry; D011199:Potentiometry / Q000379:methods; D013696:Temperature; D014508:Urea / Q000737:chemistry*; D014510:Urease / Q000737:chemistry*
chemical_list: D004800:Enzymes, Immobilized; D011108:Polymers; D020366:Methylmethacrylate; D014508:Urea; D014510:Urease; D000181:Acrylonitrile; D005976:Glutaral
keywords: Arthrobacter creatinolyticus; Cross-linking agent; PAN membrane; Potentiometric urea biosensor; Urease immobilization