Plant Wastes Converted into Antimicrobial Agents

WEDNESDAY, SEPTEMBER 20, 2023


A recent study has investigated how a natural polymer that is an element of plant cell walls could be used to make new antimicrobial treatments or coatings.

“If we can design low-cost, highly effective antimicrobials using green and eco-friendly materials, we can get the best of both worlds,” said Shudipto Dishari, Ross McCollum associate professor of chemical and biomolecular engineering at the University of Nebraska-Lincoln.

The findings were recently published in the American Chemical Society’s journal, Sustainable Chemistry and Engineering.

About the Study

According to the university, antibiotic resistance is considered a significant health concern, with the United Nations estimating that drug-resistant diseases could be responsible for 10 million deaths a year by 2050.

This presents a need for new kinds of antibiotics, but also antimicrobial coatings and other disinfecting solutions.

For the study, the researchers modified lignin from Norway spruce trees with quaternary ammonium, a positively charged functional group used to kill bacteria, viruses and mold. The modification was done in water which ensured green synthesis.

Then, the team reportedly tested this lignin-derived antimicrobial, named QAL, on an antibiotic-resistant strain of E. coli causing urinary tract infections. The positively charged groups of QAL made it easy for the lignin to attack and disrupt the outer skin of bacteria which is net negatively charged, the researchers explained.

“While antibiotic-resistant bacteria are smart enough to save themselves from the action of conventional drugs, they cannot protect themselves from the non-specific effects that QAL makes,” Dishari said.

Consequently, the antibiotic-resistant bacteria die and cannot grow further when treated with QAL, which also reportedly demonstrated no significant toxicity against human embryonic kidney cells.

“By converting an untapped agricultural/process waste like lignin into value-added antimicrobials, we can significantly lower the expense of antimicrobial treatments and coatings in large-scale applications,” Dishari said.

“From a broader perspective, sustainable, scalable production of low-cost, efficient antimicrobials from waste lignin can help to sustain pulp and paper industries, biorefineries and agricultural farms and support the bioeconomy.”

Dishari explained that, while this research used lignin from Norway spruce, the results open up “tremendous possibilities” to combat antibiotic resistance using green materials.

“The chemical structure of lignin can vary depending on the plant source, but we are up to embracing this challenge as an exciting opportunity to play with lignin chemistry and design a wide range of antimicrobials with high efficacy,” Dishari said.

Other paper co-authors include Karen Acurio Cerda, Mark Kathol and Ehsan Zamani, graduate students in chemical and biomolecular engineering; Rajib Saha, Richard L. and Carol S. McNeel Associate Professor of chemical and biomolecular engineering; Gunjan Purohit, postdoctoral research associate in biochemistry; Oleh Khalimonchuk, Susan J. Rosowski Professor of biochemistry; and Martha D. Morton, research professor of chemistry.

   

Tagged categories: Anti-microbial; Antimicrobial coatings; Asia Pacific; Bio-based materials; Coating chemistry; Coating Materials - Commercial; Coatings Technology; Colleges and Universities; EMEA (Europe, Middle East and Africa); Green coatings; Health & Safety; Health and safety; Latin America; North America; Program/Project Management; Research and development; Sustainability; Z-Continents

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