Sirirach Nanthachai , Beom Soo Kim , Kohsuke Honda , Suchada Chanprateep Napathorn
{"title":"澳大利亚偶氮单胞菌对共聚物聚(3-羟基丁酸酯-co-3-羟基戊酸酯)的综合微生物降解和闭环生物循环的可持续性研究","authors":"Sirirach Nanthachai , Beom Soo Kim , Kohsuke Honda , Suchada Chanprateep Napathorn","doi":"10.1016/j.polymdegradstab.2025.111420","DOIUrl":null,"url":null,"abstract":"<div><div>Achieving a fully closed-loop waste management system for polyhydroxyalkanoates (PHA) is a key focus for sustainable solutions. Among the one hundred forty-two PHA-producing strains tested, <em>Azohydromonas australica</em> DSM 1124 showed a remarkable ability to degrade poly (3-hydroxybutyrate-<em>co</em>-3-hydroxyvalerate, PHBV) on PHBV-suspended agar media. The effects of different carbon‒nitrogen (C/N) ratios (mol/mol) were investigated in mineral salt media (MSM) and compared with those in yeast extract peptone (YP) media. The C/N ratio of 770 yielded the greatest PHBV degradation, with 79.4 ± 4.8 % film weight loss, and subsequently resulted in 27.6 ± 2.2 % PHA content and a Y<sub>P/S</sub> of 0.245 g-PHBV produced/g-PHBV film in a one pot process. Various techniques were employed, including differential scanning calorimetry (DSC), scanning electron microscopy (SEM), gel permeation chromatography (GPC) and X-ray diffraction (XRD). X-ray diffraction confirmed that orthorhombic α-form crystals with helical chain conformations and β-form crystals with planar zigzag conformations were significantly degraded. Biological recycling in a 10-L fermenter resulted in 70.3 ± 0.1 % PHBV film weight loss by the action of PHA depolymerase enzymes, leading to the formation of oligomers and monomers. Subsequently, <em>A. australica</em> DSM 1124 has assimilated and internalized these monomers as substrates for the biosynthesis of renewed PHBV, achieving a PHA content of 12.9 ± 0.1 %. This study demonstrates the potential of <em>A. australica</em> DSM 1124 for integrated microbial degradation and closed-loop recycling, offering a one-pot sustainable approach to mitigate PHA waste accumulation in ecosystems.</div></div>","PeriodicalId":406,"journal":{"name":"Polymer Degradation and Stability","volume":"239 ","pages":"Article 111420"},"PeriodicalIF":6.3000,"publicationDate":"2025-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Towards sustainability by integrated microbial degradation and closed-loop biological recycling of the copolymer poly (3-hydroxybutyrate-co-3-hydroxyvalerate) by Azohydromonas australica DSM 1124\",\"authors\":\"Sirirach Nanthachai , Beom Soo Kim , Kohsuke Honda , Suchada Chanprateep Napathorn\",\"doi\":\"10.1016/j.polymdegradstab.2025.111420\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>Achieving a fully closed-loop waste management system for polyhydroxyalkanoates (PHA) is a key focus for sustainable solutions. Among the one hundred forty-two PHA-producing strains tested, <em>Azohydromonas australica</em> DSM 1124 showed a remarkable ability to degrade poly (3-hydroxybutyrate-<em>co</em>-3-hydroxyvalerate, PHBV) on PHBV-suspended agar media. The effects of different carbon‒nitrogen (C/N) ratios (mol/mol) were investigated in mineral salt media (MSM) and compared with those in yeast extract peptone (YP) media. The C/N ratio of 770 yielded the greatest PHBV degradation, with 79.4 ± 4.8 % film weight loss, and subsequently resulted in 27.6 ± 2.2 % PHA content and a Y<sub>P/S</sub> of 0.245 g-PHBV produced/g-PHBV film in a one pot process. Various techniques were employed, including differential scanning calorimetry (DSC), scanning electron microscopy (SEM), gel permeation chromatography (GPC) and X-ray diffraction (XRD). X-ray diffraction confirmed that orthorhombic α-form crystals with helical chain conformations and β-form crystals with planar zigzag conformations were significantly degraded. Biological recycling in a 10-L fermenter resulted in 70.3 ± 0.1 % PHBV film weight loss by the action of PHA depolymerase enzymes, leading to the formation of oligomers and monomers. Subsequently, <em>A. australica</em> DSM 1124 has assimilated and internalized these monomers as substrates for the biosynthesis of renewed PHBV, achieving a PHA content of 12.9 ± 0.1 %. This study demonstrates the potential of <em>A. australica</em> DSM 1124 for integrated microbial degradation and closed-loop recycling, offering a one-pot sustainable approach to mitigate PHA waste accumulation in ecosystems.</div></div>\",\"PeriodicalId\":406,\"journal\":{\"name\":\"Polymer Degradation and Stability\",\"volume\":\"239 \",\"pages\":\"Article 111420\"},\"PeriodicalIF\":6.3000,\"publicationDate\":\"2025-05-08\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Polymer Degradation and Stability\",\"FirstCategoryId\":\"92\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0141391025002496\",\"RegionNum\":2,\"RegionCategory\":\"化学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"POLYMER SCIENCE\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Polymer Degradation and Stability","FirstCategoryId":"92","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0141391025002496","RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"POLYMER SCIENCE","Score":null,"Total":0}
Towards sustainability by integrated microbial degradation and closed-loop biological recycling of the copolymer poly (3-hydroxybutyrate-co-3-hydroxyvalerate) by Azohydromonas australica DSM 1124
Achieving a fully closed-loop waste management system for polyhydroxyalkanoates (PHA) is a key focus for sustainable solutions. Among the one hundred forty-two PHA-producing strains tested, Azohydromonas australica DSM 1124 showed a remarkable ability to degrade poly (3-hydroxybutyrate-co-3-hydroxyvalerate, PHBV) on PHBV-suspended agar media. The effects of different carbon‒nitrogen (C/N) ratios (mol/mol) were investigated in mineral salt media (MSM) and compared with those in yeast extract peptone (YP) media. The C/N ratio of 770 yielded the greatest PHBV degradation, with 79.4 ± 4.8 % film weight loss, and subsequently resulted in 27.6 ± 2.2 % PHA content and a YP/S of 0.245 g-PHBV produced/g-PHBV film in a one pot process. Various techniques were employed, including differential scanning calorimetry (DSC), scanning electron microscopy (SEM), gel permeation chromatography (GPC) and X-ray diffraction (XRD). X-ray diffraction confirmed that orthorhombic α-form crystals with helical chain conformations and β-form crystals with planar zigzag conformations were significantly degraded. Biological recycling in a 10-L fermenter resulted in 70.3 ± 0.1 % PHBV film weight loss by the action of PHA depolymerase enzymes, leading to the formation of oligomers and monomers. Subsequently, A. australica DSM 1124 has assimilated and internalized these monomers as substrates for the biosynthesis of renewed PHBV, achieving a PHA content of 12.9 ± 0.1 %. This study demonstrates the potential of A. australica DSM 1124 for integrated microbial degradation and closed-loop recycling, offering a one-pot sustainable approach to mitigate PHA waste accumulation in ecosystems.
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.