title: Low-temperature-active and salt-tolerant β-mannanase from a newly isolated Enterobacter sp. strain N18.
abstract: A low-temperature-active and salt-tolerant β-mannanase produced by a novel mannanase-producer, Enterobacter sp. strain N18, was isolated, purified and then evaluated for its potential application as a gel-breaker in relation to viscosity reduction of guar-based hydraulic fracturing fluids used in oil field. The enzyme could lower the viscosity of guar gum solution by more than 95% within 10 min. The purified β-mannanase with molecular mass of 90 kDa displayed high activity in a broad range of pH and temperature: more than 70% of activity was retained in the pH range of 3.0-8.0 with the optimal pH 7.5, about 50% activity at 20°C with the optimal temperature 50°C. Furthermore, the enzyme retained >70% activity in the presence of 0.5-4.0 M NaCl. These properties implied that the enzyme from strain N18 had potential for serving as a gel-breaker for low temperature oil wells and other industrial fields, where chemical gel breakers were inactive due to low temperature.
authors.affiliation: State Key Laboratory of Bioreactor Engineering and Institute of Applied Chemistry, East China University of Science and Technology, Shanghai 200237, PR China.
authors.forename: Jia
authors.initials: J
authors.lastname: You
authors.affiliation: State Key Laboratory of Bioreactor Engineering and Institute of Applied Chemistry, East China University of Science and Technology, Shanghai 200237, PR China.
authors.forename: Jin-Feng
authors.initials: JF
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Bioreactor Engineering and Institute of Applied Chemistry, East China University of Science and Technology, Shanghai 200237, PR China.
authors.forename: Shi-Zhong
authors.initials: SZ
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Bioreactor Engineering and Institute of Applied Chemistry, East China University of Science and Technology, Shanghai 200237, PR China; Collaborative Innovation Center for Biomanufacturing Technology, Shanghai 200237, PR China. Electronic address: bzmu@ecust.edu.cn.
authors.forename: Bo-Zhong
authors.initials: BZ
authors.lastname: Mu
mesh_terms: D003080:Cold Temperature; D004754:Enterobacter / Q000145:classification / Q000201:enzymology* / Q000302:isolation & purification*; D005685:Galactans / Q000737:chemistry / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D008351:Mannans / Q000737:chemistry / Q000378:metabolism; D008970:Molecular Weight; D053149:Plant Gums / Q000737:chemistry / Q000378:metabolism; D055049:Salt Tolerance; D012965:Sodium Chloride / Q000494:pharmacology*; D014783:Viscosity; D044902:beta-Mannosidase / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*
chemical_list: D005685:Galactans; D008351:Mannans; D053149:Plant Gums; D012965:Sodium Chloride; C007894:guar gum; D044902:beta-Mannosidase
keywords: Enterobacter; Low-temperature-active; Salt-tolerant; Viscosity; β-Mannanase