title: Production and Characterization of α-Amylase from an Extremely Halophilic Archaeon,Haloferaxsp. HA10.
abstract: Haloarchaea are found at very high concentrations in salt-conditioned environments, hence produce enzymes which are able to catalyze reactions under harsh conditions, typical of many industrial processes. In the present study, culture conditions for extracellular amylase production from Haloarchaea isolated from a solar saltern were optimized and the purified enzyme was characterized.Haloferaxsp. HA10 showed maximum amylase production at 3 M NaCl, 37 °C, pH=7 and 1% starch content. Purified α-amylase was a calcium-dependent enzyme with an estimated molecular mass of about 66 kDa and many industrially useful properties. It was found to be stable in a broad range of pH (from 5 to 9) and NaCl concentrations (from 0.5 to 3.0 M), retaining 48% activity even at 4 M. The optimal temperature forHaloferaxsp. HA10 amylase activity was 55 °C (99% activity), and 57% activity was retained at 80 °C, which dropped to 44% with the increase of temperature to 90 or 100 °C. It was able to sustain various surfactants and detergents. To the best of our knowledge the detergent-stable α-amylases from halophilic archaeon have not been reported yet.
authors.affiliation: Department of Biotechnology, Ashok & Rita Patel Institute of Integrated Study & Research in Biotechnology and Allied Sciences (ARIBAS), New Vallabh Vidya Nagar 388121, Gujarat, India.
authors.forename: Bhakti
authors.initials: B
authors.lastname: Bajpai
authors.affiliation: Department of Bioscience and Biotechnology, Banasthali University, Distt. Tonk 304022, Rajasthan, India; Present address: 13836 Jefferson Park Dr, Apt 9102, Herndon, VA-20171, USA.
authors.forename: Monika
authors.initials: M
authors.lastname: Chaudhary
authors.affiliation: Biochemical Engineering Department, B.T. Kumaon Institute of Technology, Dwarahat 263653, Uttarakhand, India.
authors.forename: Jyoti
authors.initials: J
authors.lastname: Saxena
keywords: Haloferax sp.; archaea; halophiles; solar saltern; α-amylase