TURNING TREND?

A species of bacteria plucked out of the soil of Barabanki in Uttar Pradesh has helped scientists develop a fabric polishing process that may pave the way for smoother and more attractive denims.

Scientists at the National Chemical Laboratory in Pune have used an enzyme produced by the bacteria to devise a new “biopolishing” process that eliminates drawbacks associated with conventional denim polishing.

“This is an alternative to the traditional practice of stonewashing,” said Mala Rao, a senior scientist at the biochemical sciences division at the laboratory. She heads a team that has been looking for interesting microorganisms for industry applications. One of her team members on a routine visit to Barabanki picked up soil on a hot summer day and brought it back to the Pune centre to isolate microorganisms.

In the stonewashing process, the denim garments used to be washed with pumice stones in large industrial machines to soften the fabric through friction and abrasion, a textile industry scientist said.

“Stonewashing was the old method of making the fabric soft and smooth by removing the fibres that protrude from the surface of the fabric,” said Mohammad Safikur Rahman, head of chemical sciences at the Ahmedabad Textile Industry Research Association.

Although conventional denim finishing processes make use of enzymes from fungi, they lead to backstaining of the indigo dye on to the fabric. “The colour deposits on the rear side of the fabric which is undesirable from a cosmetic point of view,” Rahman told The Telegraph.

The biopolishing process that uses the enzyme from the bacteria from Barabanki can remove the surface fibres and smoothen the fabric with much lower levels of backstaining, Rao said. The Pune team has applied for a patent on the process of biofinishing of denims using the new enzyme.

The new enzyme replaces pumice stones and achieves the faded effect on denim fabric with minimum wear of the fabric, according to the researchers. Rahman helped the laboratory evaluate the new enzyme through the Ahmedabad association.

However, scientists of both centres cautioned that the laboratory-scale enzyme technology is not yet ready for the textile industry. The process needs to be scaled up and its economics has yet to be evaluated, Rahman said.

In earlier work, Rao had identified enzymes with potential applications in the paper and pulp and leather industries. But the enzymes are not yet in routine industrial use because of the high cost of enzyme production, Rao said.

Rao and her colleagues have been looking for extremophiles — a class of microorganisms that can survive high temperatures, pressures and unusual chemical environments.

“Industrial processes involve harsh environments, and extremophiles are sturdy microbes. We expect their enzymes to be sturdy enough to function in industrial environments,” she said.