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Updated: Jun 29, 2026
Antimicrobial Characterization of Advanced Materials for Bioengineering Applications
Published on: August 4, 2018
Antimicrobial Materials with Lime Oil and a Poly(3-hydroxyalkanoate) Produced via Valorisation of Sugar Cane Molasses
Pooja Basnett1, Elena Marcello1, Barbara Lukasiewicz1
1Faculty of Science and Technology, University of Westminster, London W1W 6UW, UK.
Abstract:
A medium chain-length polyhydroxyalkanoate (PHA) was produced by Pseudomonas mendocina CH50 using a cheap carbon substrate, sugarcane molasses. A PHA yield of 14.2% dry cell weight was achieved. Chemical analysis confirmed that the polymer produced was a medium chain-length PHA, a copolymer of 3-hydroxyoctanoate and 3-hydroxydecanoate, P(3HO-co-3HD). Lime oil, an essential oil with known antimicrobial activity, was used as an additive to P(3HO-co-3HD) to confer antibacterial properties to this biodegradable polymer. The incorporation of lime oil induced a slight decrease in crystallinity of P(3HO-co-3HD) films. The antibacterial properties of lime oil were investigated using ISO 20776 against Staphylococcus aureus 6538P and Escherichia coli 8739, showing a higher activity against the Gram-positive bacteria. The higher activity of the oil against S. aureus 6538P defined the higher efficiency of loaded polymer films against this strain. The effect of storage on the antimicrobial properties of the loaded films was investigated. After one-year storage, the content of lime oil in the films decreased, causing a reduction of the antimicrobial activity of the materials produced. However, the films still possessed antibacterial activity against S. aureus 6538P.
Insights
Researchers developed a biodegradable polymer, poly(3-hydroxyoctanoate-co-3-hydroxydecanoate) (PHA), using sugarcane molasses. Adding lime oil imparted antibacterial properties, effective against Staphylococcus aureus even after a year.
Area of Science:
- Biotechnology
- Polymer Science
- Microbiology
Background:
- Polyhydroxyalkanoates (PHAs) are biodegradable polymers with diverse applications.
- Developing cost-effective PHA production methods is crucial for wider adoption.
- Incorporating antimicrobial agents into polymers enhances their functionality.
Purpose of the Study:
- To produce a medium chain-length PHA using an inexpensive substrate.
- To functionalize the PHA with lime oil for antibacterial properties.
- To evaluate the efficacy and stability of the antimicrobial PHA.
Main Methods:
- Medium chain-length PHA production by *Pseudomonas mendocina* CH50 using sugarcane molasses.
- Chemical characterization of the PHA as P(3HO-co-3HD).
- Incorporation of lime oil into PHA films and assessment of antibacterial activity against *Staphylococcus aureus* and *Escherichia coli* using ISO 20776 standards.
- Evaluation of antimicrobial properties after one-year storage.
Main Results:
- A PHA yield of 14.2% dry cell weight was achieved.
- The produced PHA was confirmed as a copolymer of 3-hydroxyoctanoate and 3-hydroxydecanoate.
- Lime oil incorporation slightly decreased PHA film crystallinity.
- The lime oil-loaded PHA showed significant antibacterial activity, particularly against *Staphylococcus aureus*.
- Antimicrobial activity decreased after one-year storage but remained detectable.
Conclusions:
- Sugarcane molasses is a viable substrate for producing medium chain-length PHA.
- Lime oil effectively confers antibacterial properties to PHA films.
- The antimicrobial efficacy is higher against Gram-positive bacteria (*S. aureus*).
- While storage reduces antimicrobial activity, the functionalized PHA retains antibacterial properties over time.
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