Molecular cloning and characterization of a halotolerant α-amylase from marine metagenomic library derived from Arabian Sea sediments

Abstract

Functional screening of a metagenomic library of marine sediment revealed an amylolytic clone BTM109. This report states the purification and characterization of a moderately halotolerant α-amylase, with more than 51% activity in 2.5 M NaCl. The molecular mass of purified protein was determined to be 55.7 kDa by MALDI-TOF MS. The optimum pH for enzyme activity was pH 7 and temperature for maximal activity was 40 °C. At 5 mM concentration, Ca enhanced the enzyme activity indicating that the enzyme is a Ca dependent α-amylase which was confirmed by the starch hydrolysis pattern using TLC. These physico-chemical properties support the suitability of this enzyme for various industrial applications.

Computational Insights into the Selecting Mechanism of α-Amylase Immobilized on Cellulose Nanocrystals: Unveiling the Potential of α-Amylases Immobilized for Efficient Poultry Feed Hydrolysis

“…Halotolerant enzymes can withstand a range of salinities; hence, they are useful in many challenging industrial processes, in which high salt concentrations would inhibit enzymatic activities. The same halotolerant behavior was observed in a halotolerant α-amylase from marine metagenomics, which retained 51.12% of its activity when incubated at 2.5 M NaCl . These values were lower than those of free PersiAmy2 and PersiAmy3, which exhibited 116.29 and 95.00% activity, respectively, after the addition of 2 M NaCl.…”

“…The same halotolerant behavior was observed in a halotolerant α-amylase from marine metagenomics, which retained 51.12% of its activity when incubated at 2.5 M NaCl. 56 These values were lower than those of free PersiAmy2 and PersiAmy3, which exhibited 116.29 and 95.00% activity, respectively, after the addition of 2 M NaCl. Additionally, the results for native PersiAmy2 and PersiAmy3 were higher than those for a halotolerant recombinant from a haloarchaeal strain that showed less than 20% activity at 4 M NaCl.…”

Highly Efficient Computationally Derived Novel Metagenome α-Amylase With Robust Stability Under Extreme Denaturing Conditions

“…Moreover, PersiAmy1 has wide-range salt tolerance and retains high activity (88.81%) at high NaCl concentration (5 M). This result was higher than a halotolerant recombinant α-amylase from halophilic archaeal strain and halotolerant α-amylase from the marine metagenomic library (Nair et al, 2017;Verma et al, 2020). Indeed, the halotolerant, detergent-compatible PersiAmy1 could be used as a suitable alternative in the detergent industry since it presented good stabilities at different factors essential for de-staining.…”

“…Arthrobacter agilis <60% activity after 60 min at pH 9.0 >80% activity after 60 min at 70 • C - Kim et al, 2017 Bacillus methylotrophicus <100% activity after 60 min at pH 9.0 <60% activity after 60 min at 50 • C <20% activity at 20 Hmidet et al, 2019 Bacillus pseudofirmus 80% activity after 12 h at pH 9.0 <80% activity after 20 min at 50 • C 40% activity at 30 Lu et al, 2016 Metagenome-derived <80% activity after 30 min at pH 9.0 <10% activity after 30 min at 90 Nair et al, 2017 Metagenome-derived >80% activity after 14 h at pH 9.0 <10% activity after 60 min at 50 Vester et al, 2015 Metagenome-derived (PersiAmy1) 86% activity after 180 min at pH 9.0 61% activity after 180 min at 90 • C 87% activity at 0 • C This study downstream conditions, which is essential for using the enzyme in several industrial processes. PersiAmy1 withstood extreme pH and temperature and was active and stable at wide temperature and pH ranges.…”

“…Through the metagenomics approach, several α-amylases were identified to meet the industrial application ( Sindhu et al, 2017 ). A novel halotolerant α-amylase was identified from the metagenomic library of marine sediment ( Nair et al, 2017 ). Another study used the sea metagenomic data to produce a novel α-amylase with particular textile and food industries ( Nair and Bhat, 2020 ).…”