Pilot-scale production of a highly thermostable α-amylase enzyme fromThermotoga petrophilacloned intoE. coliand its application as a desizer in textile industry

Asma Zafar,Mushtaq Ahmad Saleem,Irfana Iqbal,Muhammad Nauman Aftab,Zia Ud Din

doi:10.1039/c8ra06554c

Abstract

In this study, the industrial applications of a highly thermostable α-amylase as a desizer in the textile industry was evaluated. The cloned gene was expressed in different media (ZBM, LB, ZYBM9, and ZB) with IPTG (isopropyl β-d-1-thiogalactopyranoside) used as an inducer. Lactose was also used as an alternate inducer for the T7 promoter system in E. coli. For the large-scale production of the enzyme, different parameters were optimized. The maximum enzyme production was achieved when the volume of medium was 70% of the total volume of fermenter with a 2.0 vvm air supply and 20% dissolved oxygen at a 200 rpm agitation rate. Under all the optimized conditions, the maximum enzyme production was 22.08 U ml−1 min−1 with lactose (200 mM) as an inducer in ZBM medium. The desizing potential of the purified α-amylase enzyme was calculated with different enzyme concentrations (50–300 U ml−1) at different temperatures (50–100 °C), and pHs (4–9) with varying time intervals (30–120 min). The highest desizing activity was found when 150 U ml−1 enzyme units were utilized at 85 °C and at 6.5 pH for 1 h.

Highlights

Amylases are starch-degrading enzymes that are capable of hydrolyzing the internal a-1-4 glycosidic linkage in starch arranged in the form of polymers composed of glucose units.[1]. These enzymes are considered to be one of the most important industrial enzyme and make up about 25% of the world enzyme market and have proven signi cance for biotechnology.[2,3]. These enzymes are widely distributed throughout the biodiversity and can be obtained from various sources, such as animals, plants, and microorganisms; the microbial amylases are generally considered the most able to meet industrial requirements due to their stability and broad range of industrial applications.[4,5]
Amylases are used in many industrial applications, such as food, fermentation, textile desizing, paper, detergents, starch sacchari cation, and in the pharmaceutical industries.[6,7]
As starch become soluble at 100 C and above, most industrial applications of a-amylases require their use at temperatures up to 110 C.8

Summary

Introduction

Amylases are starch-degrading enzymes that are capable of hydrolyzing the internal a-1-4 glycosidic linkage in starch arranged in the form of polymers composed of glucose units.[1] These enzymes are considered to be one of the most important industrial enzyme and make up about 25% of the world enzyme market and have proven signi cance for biotechnology.[2,3] These enzymes are widely distributed throughout the biodiversity and can be obtained from various sources, such as animals, plants, and microorganisms; the microbial amylases are generally considered the most able to meet industrial requirements due to their stability and broad range of industrial applications.[4,5] Amylases are used in many industrial applications, such as food, fermentation, textile desizing, paper, detergents, starch sacchari cation, and in the pharmaceutical industries.[6,7]. As starch become soluble at 100 C and above, most industrial applications of a-amylases require their use at temperatures up to 110 C.8 To ful l the

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Results