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A Unique and previously unrecognized Esterase (EstAII)

Technology #inv179092014

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Rania Siam
Hamza El Dorry
Yasmine M. Mohamed
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Ahmed Ellaithy
Director, Technology Transfer +20226153112
Ingy Darwish
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Patent Protection

Esterase resistant to inactivation by heavy metals

PCT Patent Application PCT/IB2014/001218
Isolation and characterization of a heavy metal-resistant, thermophilic esterase from a Red Sea Brine Pool
Nature, Scientific Reports 3, Article number: 3358 (2013)


A unique and previously unrecognized Esterase (EstATII), isolated from an extreme environment in the Red Sea, with various applications and uses in the following industries:

  • Detergent industry

  • Pulp and paper industry

  • Leather

  • Dairy products

  • Sweeteners

  • Biofuel industry

  • Production of bulk chemicals and pharmaceuticals


Currently, only a dozen thermo-stable lipases/esterases have been isolated, of which only 7 esterases of thermophilic origin had been sequenced. Newly isolated candidates like the acetylesterase, isolated from Fervidobacterium nodosum strain is considered highly thermo-stable, retaining 50% of its activity at 60°C.  However, just like all other esterases it starts to rapidly lose activity when exposed to high temperatures above 65°C or 70°C. Another issue is showing resistance to heavy metal ions, most enzymes usually show resistance to only one or two heavy metals. In order to fulfill unique niches in industrial applications, there are many growing efforts to obtain esters, from extreme environments that can withstand higher temperatures and still retain full activity.

In 2012, the global market for lipases was $100 million. Unfortunately the existing market is described as “stagnant”, as it’s in desperate need for novel, multi-stress resistant enzymes that can fulfill over 300 industrial processes that rely heavily on biocatalysts.  


The esterase was cloned from a pool of DNA, collected from an extreme environment that displays multiple harsh conditions; A brine pool at the bottom of the Red Sea, that is characterized by high temperatures (68°C), hyper-salinity, the presence of dissolved heavy metals, and a highly acidic ph.

Collected DNA was fractionated and transformed into E. coli bacteria, which expressed the DNA fragments. Colonies were grown on a lipolytic substrate that leaves a visible change in appearance upon enzymatic hydrolysis. From this a unique, previously unrecognized lipase sequence was isolated and named EstATII.

Extracted from an extreme environment, the enzyme is potentially valuable in that it has sufficient activity at a temperature of 45-75°C and retains activity at is the enzyme thermo-stable and halotolerant, it also shows high activity in alkaline conditions, despite being recovered from acidic waters. And when exposed to a battery of metal ions it showed resistance to every candidate, making it the first esterase to show resistance to high concentrations of multiple, toxic heavy metals.

temperatures as high as 80°C. It’s also “salt-tolerant”, retaining excellent activity at 4.5M NaCl.


  • EstATII is Thermophilic (optimum temperature, 65°C).

  • Halotolerant (maintains its activity in up to 4.5 M NaCl).

  • Heavy Metal Resistant; Maintains at least 60% of its activity in the presence of a wide spectrum of heavy metals.

  • Maintains activity in broad pH range.