title: Thermo-acid-stable phytase-mediated enhancement of bioethanol production using Colocasia esculenta.
abstract: Phytase production by the thermophilic mould Thermomyces lanuginosus SSBP was enhanced 8.56-fold in submerged fermentation, which was further improved in fed-batch cultivations. The protein was purified to homogeneity using ammonium sulphate precipitation, Resource Q anion exchange and Superdex gel-filtration chromatography, with an overall purification of 24.7-fold and a yield of 5.16%. The purified 49kDa protein was optimally active at 55°C and pH 5.0, and was stable between 50 and 90°C from pH 3.0-6.0, with a half-life of 138.6min at 70°C. It was moderately stimulated by Ba+2and Mg+2. The enzyme reduced phytate content in Colocasia esculenta starch (from 1.43mg/g to 0.05mg/g) that resulted in an improvement in the availability of fermentable sugars with a concomitant reduction in viscosity and 1.59-fold improvement in ethanol production. Thermo-acid-stable phytase from T. lanuginosus SSBP could be of major biotechnological interest, especially due to its robustness and wide applicability.
authors.affiliation: Department of Biotechnology and Food Technology, Faculty of Applied Sciences, Durban University of Technology, Durban 4000, South Africa.
authors.forename: Melvin
authors.initials: M
authors.lastname: Makolomakwa
authors.affiliation: Department of Biotechnology and Food Technology, Faculty of Applied Sciences, Durban University of Technology, Durban 4000, South Africa.
authors.forename: Adarsh Kumar
authors.initials: AK
authors.lastname: Puri
authors.affiliation: Department of Biotechnology and Food Technology, Faculty of Applied Sciences, Durban University of Technology, Durban 4000, South Africa.
authors.forename: Kugen
authors.initials: K
authors.lastname: Permaul
authors.affiliation: Department of Biotechnology and Food Technology, Faculty of Applied Sciences, Durban University of Technology, Durban 4000, South Africa. Electronic address: singhs@dut.ac.za.
authors.forename: Suren
authors.initials: S
authors.lastname: Singh
mesh_terms: D010832:6-Phytase / Q000096:biosynthesis*; D031060:Colocasia; D000431:Ethanol / Q000378:metabolism*; D005285:Fermentation; D006207:Half-Life; D006863:Hydrogen-Ion Concentration; D010833:Phytic Acid
chemical_list: D000431:Ethanol; D010833:Phytic Acid; D010832:6-Phytase
keywords: Bioethanol; Colocasia esculenta; Phytase; Thermo-acid-stable; Thermomyces lanuginosus SSBP