Biodegradation of unpretreated low-density polyethylene (LDPE) by thermophiles isolated from Paku hot springs water and sediment in Sarawak, Borneo, Malaysia

Plastic pollution has emerged as a significant environmental concern nowadays, necessitating innovative solutions for its mitigation. Hot springs, while traditionally valued for their health and relaxation benefits, also present unique environments that may harbour thermophile bacteria species capab...

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Main Authors: Sabrina Rancang Khairul, Seng, Chiew Toh, Arlene Debbie Lingoh, Sui, Sien Leong
Format: Article
Language:en
Published: Penerbit Universiti Kebangsaan Malaysia 2025
Online Access:http://journalarticle.ukm.my/26532/1/ML%207.pdf
http://journalarticle.ukm.my/26532/
https://jms.mabjournal.com/index.php/mab/issue/view/69
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author Sabrina Rancang Khairul,
Seng, Chiew Toh
Arlene Debbie Lingoh,
Sui, Sien Leong
author_facet Sabrina Rancang Khairul,
Seng, Chiew Toh
Arlene Debbie Lingoh,
Sui, Sien Leong
author_sort Sabrina Rancang Khairul,
building Tun Sri Lanang Library
collection Institutional Repository
content_provider Universiti Kebangsaan Malaysia
content_source UKM Journal Article Repository
continent Asia
country Malaysia
description Plastic pollution has emerged as a significant environmental concern nowadays, necessitating innovative solutions for its mitigation. Hot springs, while traditionally valued for their health and relaxation benefits, also present unique environments that may harbour thermophile bacteria species capable of degrading plastic polymers. The study aimed to screen thermophiles from Sarawak hot springs for the biodegradation of potential low-density polyethylene (LDPE) film and evaluate their efficiency in degrading the plastic in 30 days. Water and sediment samples were collected from each pond of the Paku hot spring in Sarawak, Borneo, Malaysia, in triplicate. The thermophiles were cultivated in an enriched medium supplemented with 0.5% (w/v) PE powder at 55°C for 5 days. Colony morphology and Gram staining were carried out. Screening of isolates for LDPE biodegradation was conducted using the BATH test and, clear zone assay. Additionally, the efficiency of the isolates for 30 days of LDPE biodegradation was evaluated using the pH change, bacteria growth observation, and weight loss method. A total of 96 thermophilic isolates were cultured, 11 isolates exhibited hydrophobicity levels above 30%, and 7 isolates showed clear zone formation. After the biodegradation process, the pH was slightly decreased to pH 6.5. The bacterial colonies were Gram-positive (3) and Gram-negative (4) short rods. Isolates SPK(W)M1(1), SPK(SD)P1(2), and SPK(SD)P1(3) resulted in increased of growth (OD600 0.06 ± 0.02, OD600 0.08 ± 0.01 & OD600 0.1 ± 0.02, respectively). The highest growth absorbance OD600 was shown by isolate SPK(SD)P1(3), while isolate SPK(W)M1(1) showed the highest LDPE film weight reduction of 10 % (0.45 ± 0.05 g). The thermophiles SPK(SD)P1(3) and SPK(W)M1(1) are potentially to be used to biodegrade LDPE plastic. The preliminary study offers insight into microbial biodegradation mechanisms; further research and advanced sequencing techniques are necessary for a thorough analysis of the metabolic pathways involved.
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spelling my-ukm.journal.265322026-02-10T01:05:05Z http://journalarticle.ukm.my/26532/ Biodegradation of unpretreated low-density polyethylene (LDPE) by thermophiles isolated from Paku hot springs water and sediment in Sarawak, Borneo, Malaysia Sabrina Rancang Khairul, Seng, Chiew Toh Arlene Debbie Lingoh, Sui, Sien Leong Plastic pollution has emerged as a significant environmental concern nowadays, necessitating innovative solutions for its mitigation. Hot springs, while traditionally valued for their health and relaxation benefits, also present unique environments that may harbour thermophile bacteria species capable of degrading plastic polymers. The study aimed to screen thermophiles from Sarawak hot springs for the biodegradation of potential low-density polyethylene (LDPE) film and evaluate their efficiency in degrading the plastic in 30 days. Water and sediment samples were collected from each pond of the Paku hot spring in Sarawak, Borneo, Malaysia, in triplicate. The thermophiles were cultivated in an enriched medium supplemented with 0.5% (w/v) PE powder at 55°C for 5 days. Colony morphology and Gram staining were carried out. Screening of isolates for LDPE biodegradation was conducted using the BATH test and, clear zone assay. Additionally, the efficiency of the isolates for 30 days of LDPE biodegradation was evaluated using the pH change, bacteria growth observation, and weight loss method. A total of 96 thermophilic isolates were cultured, 11 isolates exhibited hydrophobicity levels above 30%, and 7 isolates showed clear zone formation. After the biodegradation process, the pH was slightly decreased to pH 6.5. The bacterial colonies were Gram-positive (3) and Gram-negative (4) short rods. Isolates SPK(W)M1(1), SPK(SD)P1(2), and SPK(SD)P1(3) resulted in increased of growth (OD600 0.06 ± 0.02, OD600 0.08 ± 0.01 & OD600 0.1 ± 0.02, respectively). The highest growth absorbance OD600 was shown by isolate SPK(SD)P1(3), while isolate SPK(W)M1(1) showed the highest LDPE film weight reduction of 10 % (0.45 ± 0.05 g). The thermophiles SPK(SD)P1(3) and SPK(W)M1(1) are potentially to be used to biodegrade LDPE plastic. The preliminary study offers insight into microbial biodegradation mechanisms; further research and advanced sequencing techniques are necessary for a thorough analysis of the metabolic pathways involved. Penerbit Universiti Kebangsaan Malaysia 2025 Article PeerReviewed application/pdf en http://journalarticle.ukm.my/26532/1/ML%207.pdf Sabrina Rancang Khairul, and Seng, Chiew Toh and Arlene Debbie Lingoh, and Sui, Sien Leong (2025) Biodegradation of unpretreated low-density polyethylene (LDPE) by thermophiles isolated from Paku hot springs water and sediment in Sarawak, Borneo, Malaysia. Malaysian Applied Biology, 54 (4). pp. 78-88. ISSN 0126-8643 https://jms.mabjournal.com/index.php/mab/issue/view/69
spellingShingle Sabrina Rancang Khairul,
Seng, Chiew Toh
Arlene Debbie Lingoh,
Sui, Sien Leong
Biodegradation of unpretreated low-density polyethylene (LDPE) by thermophiles isolated from Paku hot springs water and sediment in Sarawak, Borneo, Malaysia
title Biodegradation of unpretreated low-density polyethylene (LDPE) by thermophiles isolated from Paku hot springs water and sediment in Sarawak, Borneo, Malaysia
title_full Biodegradation of unpretreated low-density polyethylene (LDPE) by thermophiles isolated from Paku hot springs water and sediment in Sarawak, Borneo, Malaysia
title_fullStr Biodegradation of unpretreated low-density polyethylene (LDPE) by thermophiles isolated from Paku hot springs water and sediment in Sarawak, Borneo, Malaysia
title_full_unstemmed Biodegradation of unpretreated low-density polyethylene (LDPE) by thermophiles isolated from Paku hot springs water and sediment in Sarawak, Borneo, Malaysia
title_short Biodegradation of unpretreated low-density polyethylene (LDPE) by thermophiles isolated from Paku hot springs water and sediment in Sarawak, Borneo, Malaysia
title_sort biodegradation of unpretreated low-density polyethylene (ldpe) by thermophiles isolated from paku hot springs water and sediment in sarawak, borneo, malaysia
url http://journalarticle.ukm.my/26532/1/ML%207.pdf
http://journalarticle.ukm.my/26532/
https://jms.mabjournal.com/index.php/mab/issue/view/69
url_provider http://journalarticle.ukm.my/