Esterase Enzyme

13.01.2025

Esterase Enzyme

Why in the news?                        

            A team of researchers has successfully used an enzyme  esterase enzyme to break down diethyl hexyl phthalate (DEHP) plasticizer.

About Esterase Enzyme:

• It is produced by soil bacteria Sulfobacillus acidophilus.
• The enzyme was structurally characterized using X-ray crystallography.
• It remains active for about a month and catalyzes the degradation of diethyl hexyl phthalate (DEHP) plasticizer with significant efficiency.
• It breaks down the DEHP plasticizer into two products — mono-(2-ethylhexyl) phthalate (MEHP) and 2-ethyl hexanol.
• This esterase enzyme, along with other enzymes identified by their group previously, can convert high molecular weight phthalate plasticizers into water and carbon-dioxide.
• Researchers also found that the esterase enzyme can bind to molecules similar to polypropylene used in plastics, making it a potential tool for extracting polypropylene from contaminated water sources.
• Researchers also found three other enzymes from Comamonas testosteroni bacteria in 2017, that breaks down the phthalates produced by DEHP degradation into carbon-dioxide and water.
• Putting all the enzymes into bacteria will speed up the degradation process.

Mechanism of the Esterase Enzyme:

○They used the enzymes in sequence to first break down DEHP to MEHP and 2-ethyl hexanol using esterase enzymes.

○MEHP was degraded to phthalate using another enzyme.

○The phthalate was then converted to intermediate compounds using a third enzyme (phthalate dioxygenase).

○The intermediate compounds are then converted into protocatechuate by the enzyme phthalate decarboxylase.

○Once protocatechuate is produced, the tricarboxylic acid cycle of the bacteria, which is common in all bacteria, converts it to carbon-dioxide and water.

• The enzymes, whether used for degradation or not, will remain active only for a short time. But once integrated into bacteria, they remain active for a longer time and the bacteria can be used continuously for degrading the plasticizers.
• But when the enzymes are used without integrating into bacteria, a fresh batch of enzymes needs to be produced to continue the degradation process.

What are Plasticizers?

• These are chemicals added to plastics and personal care products to enhance flexibility and shine, and are commonly found in items such as baby toys, shampoos, soaps, and food containers.
• Plasticizers can be absorbed through the skin, making them a direct threat to human health.

                                                                     Source: The Hindu

Consider the following statements regarding the Esterase enzyme:

1. It is produced by soil bacteria Sulfobacillus acidophilus.

2. It can break down diethyl hexyl phthalate (DEHP) plasticizers with significant efficiency.

Which of the statements given above is/are correct?

A.1 only

B.2 only

C.Both 1 and 2

D.Neither 1 nor 2

Answer C