Isolation and characterization of high-HHx PHA degrading bacterium from mangrove ecosystem using an improved PHA-agar plate assay

IF 6.3 2区化学 Q1 POLYMER SCIENCE

Polymer Degradation and Stability Pub Date : 2025-05-23 DOI:10.1016/j.polymdegradstab.2025.111434

Taufiq Ahmad Syauqi, Azura Ahmad, Hui Jia Tang, Jia Hui Wan, Kumar Sudesh

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引用次数: 0

Abstract

The accumulation of plastic debris increasingly impacts mangrove ecosystems. Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHx), a biodegradable alternative to conventional plastics, can reduce environmental persistence. Despite prior studies on PHBHx degradation in mangroves, the microbial communities responsible for this process remain underexplored. This study developed a novel, surfactant-free PHA-agar plate assay to isolate and characterize PHA-degrading bacteria from a tropical mangrove ecosystem. A PHA-degrading bacterium was isolated from the plastisphere of a degraded PHBHx straw and identified as Priestia sp. USM5 via phylogenetic analysis. The strain efficiently degraded PHBHx films with 3HHx compositions up to 27 mol%, achieving complete degradation of PHBHx-8%, 97.4% of PHBHx-11%, and 42% of PHBHx-27% within 14 days. The strain exhibited growth and degradation activity across a temperature range of 25-45°C and salinity levels of 0-7% (w/v) NaCl, with optimal degradation observed at 30-37°C and in seawater with a salinity of approximately 3%. To the extent of our knowledge, this is the first report of PHA-degrading bacteria isolated from a tropical mangrove ecosystem. These findings provide new insights into microbial PHBHx degradation in mangroves and highlight the ecological and biotechnological significance of Priestia sp. USM5. The improved PHA-agar plate assay offers a valuable tool for advancing research on bioplastic degradation in tropical environments.

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利用改进的PHA-琼脂平板法从红树林生态系统中分离高hhx PHA降解细菌并进行鉴定

塑料垃圾的堆积对红树林生态系统的影响越来越大。聚（3-羟基丁酸酯-co-3-羟基己酸酯）（PHBHx）是一种可生物降解的传统塑料替代品，可以减少环境持久性。尽管先前对红树林中PHBHx的降解进行了研究，但负责这一过程的微生物群落仍未得到充分探索。本研究开发了一种新颖的，无表面活性剂的pha -琼脂平板检测方法，用于从热带红树林生态系统中分离和表征pha降解细菌。从降解的PHBHx秸秆的塑料球中分离到一株pha降解菌，经系统发育分析鉴定为Priestia sp. USM5。菌株对3HHx含量高达27 mol%的PHBHx膜进行了高效降解，在14天内，PHBHx-8%、PHBHx-11%和PHBHx-27%的降解率分别达到97.4%和42%。菌株在25-45°C的温度范围和0-7% (w/v) NaCl的盐度水平下均表现出生长和降解活性，在30-37°C和约3%盐度的海水中降解效果最佳。据我们所知，这是第一个从热带红树林生态系统中分离出pha降解细菌的报告。这些发现为红树林中PHBHx的微生物降解提供了新的见解，并突出了Priestia sp. USM5的生态和生物技术意义。改进的pha -琼脂平板法为推进热带环境中生物塑料降解的研究提供了有价值的工具。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Polymer Degradation and Stability 化学-高分子科学

CiteScore

10.10

自引率

10.20%

发文量

325

审稿时长

23 days

期刊介绍： Polymer Degradation and Stability deals with the degradation reactions and their control which are a major preoccupation of practitioners of the many and diverse aspects of modern polymer technology. Deteriorative reactions occur during processing, when polymers are subjected to heat, oxygen and mechanical stress, and during the useful life of the materials when oxygen and sunlight are the most important degradative agencies. In more specialised applications, degradation may be induced by high energy radiation, ozone, atmospheric pollutants, mechanical stress, biological action, hydrolysis and many other influences. The mechanisms of these reactions and stabilisation processes must be understood if the technology and application of polymers are to continue to advance. The reporting of investigations of this kind is therefore a major function of this journal. However there are also new developments in polymer technology in which degradation processes find positive applications. For example, photodegradable plastics are now available, the recycling of polymeric products will become increasingly important, degradation and combustion studies are involved in the definition of the fire hazards which are associated with polymeric materials and the microelectronics industry is vitally dependent upon polymer degradation in the manufacture of its circuitry. Polymer properties may also be improved by processes like curing and grafting, the chemistry of which can be closely related to that which causes physical deterioration in other circumstances.