Malays. J. Anal. Sci. Volume 30 Number 3 (2026): 1493

 

Research Article

 

Rhamnolipid production by Pseudomonas aeruginosa UMTKB-5 using bio-oil derived from microwave co-pyrolysis of hospital plastic wastes and its characterization

 

Seng Hon Kee1, Shin Ying Foong2, Diane Monique S. Baladjay3, Neaven Bon Joy M. Marcial3, Jonel P. Saludes4,5, Doralyn Dalisay3,6, Su Shiung Lam2,7 and Kesaven Bhubalan1,8,9*

 

1Faculty of Science and Marine Environment, Universiti Malaysia Terengganu, 21030 Kuala Nerus, Terengganu, Malaysia

2Higher Institution Centre of Excellence (HICoE), Institute of Tropical Aquaculture and Fisheries (AKUATROP), Universiti Malaysia Terengganu, 21030 Kuala Nerus, Terengganu, Malaysia

3Center for Chemical Biology and Biotechnology (C2B2), University of San Agustin, Iloilo City, Philippines

4Center for Natural Drug Discovery and Development (CND3), University of San Agustin, Iloilo City, Philippines

5Department of Chemistry, University of San Agustin, Iloilo City, Philippines

6Department of Biology, University of San Agustin, Iloilo City, Philippines

7Sustainability Cluster, School of Engineering, University of Petroleum & Energy Studies, Dehradun, Uttarakhand 248007, India

8Institute of Climate Adaptation and Marine Biotechnology, Universiti Malaysia Terengganu, 21030 Kuala Nerus, Terengganu, Malaysia

9Microplastic Research Interest Group, Universiti Malaysia Terengganu, 21030 Kuala Nerus, Terengganu, Malaysia

 

*Corresponding author: kesaven@umt.edu.my

 

Received: 21 July 2025; Revised: 26 January 2026; Accepted: 4 May 2026; Published: 30 June 2026

Abstract

Rhamnolipid (RL) is a bacteria-derived biosurfactant known for its eco-friendly properties, but it is expensive to produce due to high costs required for pure substrate-based carbon sources. Recently, microwave co-pyrolysis (MCP) for converting wastes to value-added products has been the spotlight. The MCP of hospital plastic wastes (HPW) and used cooking oil (UCO) can produce alkane-rich bio-oil with potential to be a carbon source for microbial transformation. Therefore, this study investigated the best parameters for RL production by Pseudomonas aeruginosa UMTKB-5 using bio-oil and the characterisation of the RL. MCP of HPW and UCO showed higher heating rate (10-17 °C/min) generating alkane-rich bio-oils characterised using Gas Chromatography-Mass Spectrometry (GCMS). 1g/L of U1H2, urea, 7% (v/v) inoculum size and 200 rpm agitation speed were the best parameters (producing up to 5.000±0.793 mg/L RL). The RL was characterised using Fourier Transform Infrared Spectroscopy (FTIR) and Ultra Performance Liquid Chromatography (UPLC). It comprises of RL functional groups and congeners, Rha-C10-C10 and RhaRha-C10-C10. The RL produced by the strain has more hydrophilicity making it a suitable candidate for bioremediation and washing detergents. Hence, this study proves that MCP of HPW and UCO derived bio-oil is a suitable carbon source for RL biosynthesis.

 

Keywords: Rhamnolipid, Pseudomonas aeruginosa, microwave co-pyrolysis, bio-oil, hospital plastic waste

 

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