Statistical optimization of a novel extracellular alkaline and thermostable amylase production from thermophilic Actinomadura keratinilytica sp. Cpt29 and its potential application in detergent industry

Optimization and purification of a novel calcium-independent thermostable, α-amylase produced by Bacillus licheniformis UDS-5

Microbial amylases should essentially remain active at higher temperatures, and in the alkaline pH and a range of surfactants to be suitable as detergent additives. In the present study, a thermophilic amylase producing bacterium, Bacillus licheniformis UDS-5 was isolated from Unai hot water spring in Gujarat, India. It was identified as a potent amylase producer during starch plate-based screening process. Therefore, the physicochemical parameters influencing amylase production were optimized using Plackett-Burman design and Central Composite Design. The amylase was purified through ammonium sulfate precipitation, size exclusion and ion exchange chromatography, achieving the purification fold and yield to be 9.2 and 40.6%, respectively. The enzyme displayed robust stability and activity across a wide range of temperatures and pHs, with an increased half-life and reduced deactivation rate constant. The amylase exhibited optimal catalysis at 70 °C and pH 8. The kinetic studies revealed Km and Vmax values of 0.58 mg/mL and 2528 μmol/mL/min, respectively. Besides, the purified amylase displayed stability in the presence of various metal ions, surfactants, and chelators suggesting its potential for industrial applications, particularly in the detergent industry. Moreover, detergent application studies demonstrated its efficacy in enhancing washing performance. A comparative profile on washing efficiency of the studied amylase and the commercial amylase with various detergents pointed towards its possible future use as a detergent additive.

Detergent-stable amylase production by Paenibacillus lactis strain OPSA3 isolated from soil; optimization by response surface methodology

This study aimed to isolate thermostable, alkaliphilic, and detergent-tolerant amylase-producing bacteria. Pure isolates from environmental samples were screened on a starch-based medium (pH 11), and selected isolates were identified using cultural and molecular techniques. Product optimization studies were conducted, and secreted amylase was partially purified using 40% (w/v) saturation ammonium sulfate at 4 °C. The wash performance of concentrated amylase was analyzed. A novel isolate, Paenibacillus lactis OPSA3, was selected for further studies. The isolate produced amylase optimally when grown on banana peels and soybean extracts, which are agro-wastes. Optimization by Response surface Methodology resulted in a 2.1-fold increase in alkaliphilic amylase production. A 2.46-fold purification was achieved, with an enzyme activity yield of 79.53% and specific activity of 26.19 Umg^-1. Wash performance analysis using the amylase supplemented with boiled commercial detergent (kiln®) showed good cleaning efficiency. The amylase has the potential for application as a component of green detergent.

Heterologous expression and biochemical characterization of novel multifunctional thermostable α-amylase from hot-spring metagenome

Hot-springs are regarded as the best source of industrially significant biocules and one of the unique locations for extremophiles. The α-amylase is one of the most important enzymes used in starch consuming industries, where the need of thermostability is paramount. In this study, the full metagenome sequences obtained from the soil of Tuwa hot-spring (Gujarat, India) were examined for the presence of several thermostable enzymes using bioinformatic techniques. The whole gene sequence for α-amylase was found from the metagenome. The α-amylase gene was amplified, cloned, and expressed in Escherichia coli and further characterized in vitro. The rm-α-amylase was found optimally active at 60 °C and at pH 6.0 and showed significantly high activity in 0.1 mM Co²⁺ as well as in other heavy metal ions without any effect on its thermostability. Apart from α-amylase activity the purified rm-α-amylase was also shown to hydrolyse agar, xylan, pectin, alginate and cellulose. To our knowledge, this is the first report of a new, multifunctional, thermostable amylase that was discovered from the hot-spring metagenomes. Owing to their multifunctionality, resilience towards high temperature and heavy metal ions, stability with solvents, additives and inhibitors, rm-α-amylase can be exploited for a variety of biotechnological applications.

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

α-Amylases are among the very critical enzymes used for different industrial purposes. Most α-amylases cannot accomplish the requirement of industrial conditions and easily lose their activity in harsh environments. In this study, a novel α-amylase named PersiAmy1 has been identified through the multistage in silico screening pipeline from the rumen metagenomic data. The long-term storage of PersiAmy1 in low and high temperatures demonstrated 82.13 and 71.01% activities after 36 days of incubation at 4 and 50°C, respectively. The stable α-amylase retained 61.09% of its activity after 180 min of incubation at 90°C and was highly stable in a broad pH range, showing 60.48 and 86.05% activities at pH 4.0 and pH 9.0 after 180 min of incubation, respectively. Also, the enzyme could resist the high-salinity condition and demonstrated 88.81% activity in the presence of 5 M NaCl. PersiAmy1 showed more than 74% activity in the presence of various metal ions. The addition of the detergents, surfactants, and organic solvents did not affect the α-amylase activity considerably. Substrate spectrum analysis showed that PersiAmy1 could act on a wide array of substrates. PersiAmy1 showed high stability in inhibitors and superb activity in downstream conditions, thus useful in detergent and baking industries. Investigating the applicability in detergent formulation, PersiAmy1 showed more than 69% activity after incubation with commercial detergents at different temperatures (30–50°C) and retained more than 56% activity after incubation with commercial detergents for 3 h at 10°C. Furthermore, the results of the wash performance analysis exhibited a good stain removal at 10°C. The power of PersiAmy1 in the bread industry revealed soft, chewable crumbs with improved volume and porosity compared with control. This study highlights the intense power of robust novel PersiAmy1 as a functional bio-additive in many industrial applications.