In this experimental research, different types of essential oils (EOs) were blended with polyhydroxybutyrate (PHB) to study the influence of these additives on PHB degradation. The blends were developed by incorporating three terpenoids at two concentrations (1 and 3%). The mineralization rate obtained from CO2 released from each sample was the factor that defined biodegradation. Furthermore, scanning electron microscope (SEM), differential scanning calorimetry (DSC), and dynamic mechanical analysis (DMA) were used in this research. The biodegradation percentages of PHB blended with 3% of eucalyptol, limonene, and thymol after 226 days were reached 66.4%, 73.3%, and 76.9%, respectively, while the rate for pure PHB was 100% after 198 days, and SEM images proved these results. Mechanical analysis of the samples showed that eucalyptol had the highest resistance level, even before the burial test. The other additives showed excellent mechanical properties although they had less mechanical strength than pure PHB after extrusion. The samples' mechanical properties improved due to their crystallinity and decreased glass transition temperature (Tg). DSC results showed that blending terpenoids caused a reduction in Tg, which is evident in the DMA results, and a negligible reduction in melting point (Tm).

Centre of Polymer Systems University Institute Tomas Bata University in Zlín Tr T Bati 5678 76001 Zlín Czech Republic

Department of Environmental Protection Engineering Faculty of Technology Tomas Bata University in Zlín T G Masaryk Square 5555 76001 Zlín Czech Republic

Department of Polymer Engineering Faculty of Technology Tomas Bata University in Zlín T G Masaryk Square 5555 76001 Zlín Czech Republic

See more in PubMed

Wang J., Emmerich L., Wu J., Vana P., Zhang K. Hydroplastic polymers as eco-friendly hydrosetting plastics. Nat. Sustain. 2021;4:877–883. doi: 10.1038/s41893-021-00743-1. DOI

Fogašová M., Figalla S., Danišová L., Medlenová E., Hlaváčiková S., Bočkaj J., Plavec R., Alexy P., Repiská M., Přikryl R., et al. PLA/PHB-Based Materials Fully Biodegradable under Both Industrial and Home-Composting Conditions. Polymers. 2022;14:4113. doi: 10.3390/polym14194113. PubMed DOI PMC

Mangeon C., Michely L., Rios De Anda A., Thevenieau F., Renard E., Langlois V. Natural Terpenes Used as Plasticizers for Poly(3-hydroxybutyrate) ACS Sustain. Chem. Eng. 2018;6:16160–16168. doi: 10.1021/acssuschemeng.8b02896. DOI

Koller M. Recycling of waste streams of the biotechnological poly(hydroxyalkanoate) production by Haloferax mediterranei on whey. Int. J. Polym. Sci. 2015;2015:370164. doi: 10.1155/2015/370164. DOI

Rech C.R., da Silva Brabes K.C., Bagnara e Silva B.E., Bittencourt P.R.S., Koschevic M.T., da Silveira T.F.S., Martines M.A.U., Caon T., Martelli S.M. Biodegradation of eugenol-loaded polyhydroxybutyrate films in different soil types. Case Stud. Chem. Environ. Eng. 2020;2:100014. doi: 10.1016/j.cscee.2020.100014. DOI

Šerá J., Kadlečková M., Fayyazbakhsh A., Kučabová V., Koutný M. Occurrence and analysis of thermophilic poly(Butylene adipate-co-terephthalate)-degrading microorganisms in temperate zone soils. Int. J. Mol. Sci. 2020;21:7857. doi: 10.3390/ijms21217857. PubMed DOI PMC

Moradali M.F., Rehm B.H.A. Bacterial biopolymers: From pathogenesis to advanced materials. Nat. Rev. Microbiol. 2020;18:195–210. doi: 10.1038/s41579-019-0313-3. PubMed DOI PMC

Jiang X.R., Yan X., Yu L.P., Liu X.Y., Chen G.Q. Hyperproduction of 3-hydroxypropionate by Halomonas bluephagenesis. Nat. Commun. 2021;12:1513. doi: 10.1038/s41467-021-21632-3. PubMed DOI PMC

Gao M., Du D., Bo Z., Sui L. Poly-β-hydroxybutyrate (PHB)-accumulating Halomonas improves the survival, growth, robustness and modifies the gut microbial composition of Litopenaeus vannamei postlarvae. Aquaculture. 2019;500:607–612. doi: 10.1016/j.aquaculture.2018.10.032. DOI

Briassoulis D., Tserotas P., Athanasoulia I.-G. Alternative optimization routes for improving the performance of poly(3-hydroxybutyrate) (PHB) based plastics. J. Clean. Prod. 2021;318:128555. doi: 10.1016/j.jclepro.2021.128555. DOI

Lee J., Park H.J., Moon M., Lee J.-S., Min K. Recent progress and challenges in microbial polyhydroxybutyrate (PHB) production from CO2 as a sustainable feedstock: A state-of-the-art review. Bioresour. Technol. 2021;339:125616. doi: 10.1016/j.biortech.2021.125616. PubMed DOI

Park S., Yang Y.H., Choi K.Y. One-pot production of thermostable PHB biodegradable polymer by co-producing bio-melanin pigment in engineered Escherichia coli. Biomass Conv. Bioref. 2022 doi: 10.1007/s13399-021-02222-1. DOI

Pachekoski W.M., Agnelli J.A.M., Belem L.P. Thermal, mechanical and morphological properties of poly (hydroxybutyrate) and polypropylene blends after processing. Mater. Res. 2009;12:159–164. doi: 10.1590/S1516-14392009000200008. DOI

Aydemir D., Gardner D.J. Biopolymer blends of polyhydroxybutyrate and polylactic acid reinforced with cellulose nanofibrils. Carbohydr. Polym. 2020;250:116867. doi: 10.1016/j.carbpol.2020.116867. PubMed DOI

Mohanrasu K., Premnath N., Siva Prakash G., Sudhakar M., Boobalan T., Arun A. Exploring multi potential uses of marine bacteria; an integrated approach for PHB production, PAHs and polyethylene biodegradation. J. Photochem. Photobiol. B Biol. 2018;185:55–65. doi: 10.1016/j.jphotobiol.2018.05.014. PubMed DOI

Robledo-Ortíz J.R., González-López M.E., Martín del Campo A.S., Pérez-Fonseca A.A. Lignocellulosic Materials as Reinforcement of Polyhydroxybutyrate and its Copolymer with Hydroxyvalerate: A Review. J. Polym. Environ. 2021;29:1350–1364. doi: 10.1007/s10924-020-01979-2. PubMed DOI

Basnett P., Marcello E., Lukasiewicz B., Nigmatullin R., Paxinou A., Ahmad M.H., Gurumayum B., Roy I. Antimicrobial materials with lime oil and a poly(3-hydroxyalkanoate) produced via valorisation of sugar cane molasses. J. Funct. Biomater. 2020;11:24. doi: 10.3390/jfb11020024. PubMed DOI PMC

Nishida M., Tanaka T., Hayakawa Y., Ogura T., Ito Y., Nishida M. Multi-scale instrumental analyses of plasticized polyhydroxyalkanoates (PHA) blended with polycaprolactone (PCL) and the effects of crosslinkers and graft copolymers. RSC Adv. 2019;9:1551–1561. doi: 10.1039/C8RA10045D. PubMed DOI PMC

Rech C.R., Brabes K.C.S., Silva B.E.B., Martines M.A.U., Silveira T.F.S., Alberton J., Amadeu C.A.A., Caon T., Arruda E.J., Martelli S.M. Antimicrobial and Physical–Mechanical Properties of Polyhydroxybutyrate Edible Films Containing Essential Oil Mixtures. J. Polym. Environ. 2020;29:1202–1211. doi: 10.1007/s10924-020-01943-0. DOI

Miao L., Walton W.C., Wang L., Li L., Wang Y. Characterization of polylactic acids-polyhydroxybutyrate based packaging film with fennel oil, and its application on oysters. Food Packag. Shelf Life. 2019;22:100388. doi: 10.1016/j.fpsl.2019.100388. DOI

Namivandi-Zangeneh R., Yang Y., Xu S., Wong E.H.H., Boyer C. Antibiofilm Platform based on the Combination of Antimicrobial Polymers and Essential Oils. Biomacromolecules. 2020;21:262–272. doi: 10.1021/acs.biomac.9b01278. PubMed DOI

Ventura H., Laguna-Gutiérrez E., Rodriguez-Perez M.A., Ardanuy M. Effect of chain extender and water-quenching on the properties of poly(3-hydroxybutyrate-co-4-hydroxybutyrate) foams for its production by extrusion foaming. Eur. Polym. J. 2016;85:14–25. doi: 10.1016/j.eurpolymj.2016.10.001. DOI

Duangphet S., Szegda D., Song J., Tarverdi K. The Effect of Chain Extender on Poly(3-hydroxybutyrate-co-3-hydroxyvalerate): Thermal Degradation, Crystallization, and Rheological Behaviours. J. Polym. Environ. 2014;22:1–8. doi: 10.1007/s10924-012-0568-5. DOI

Narayanan A., Neera, Mallesha, Ramana K.V. Synergized antimicrobial activity of eugenol incorporated polyhydroxybutyrate films against food spoilage microorganisms in conjunction with pediocin. Appl. Biochem. Biotechnol. 2013;170:1379–1388. doi: 10.1007/s12010-013-0267-2. PubMed DOI

de Oliveira K.Á.R., de Sousa J.P., da Costa Medeiros J.A., de Figueiredo R.C.B.Q., Magnani M., de Siqueira J.P., de Souza E.L. Synergistic inhibition of bacteria associated with minimally processed vegetables in mixed culture by carvacrol and 1,8-cineole. Food Control. 2015;47:334–339. doi: 10.1016/j.foodcont.2014.07.014. DOI

Monistero V., Barberio A., Biscarini F., Cremonesi P., Castiglioni B., Graber H.U., Bottini E., Ceballos-Marquez A., Kroemker V., Petzer I.M., et al. Different distribution of antimicrobial resistance genes and virulence profiles of Staphylococcus aureus strains isolated from clinical mastitis in six countries. J. Dairy Sci. 2020;103:3431–3446. doi: 10.3168/jds.2019-17141. PubMed DOI

Porfírio E.M., Melo H.M., Pereira A.M.G., Cavalcante T.T.A., Gomes G.A., De Carvalho M.G., Costa R.A., Catunda F.E.A. In vitro antibacterial and antibiofilm activity of lippia alba essential oil, citral, and carvone against staphylococcus aureus. Sci. World J. 2017;2017:4962707. doi: 10.1155/2017/4962707. PubMed DOI PMC

Huang F., Kong J., Ju J., Zhang Y., Guo Y., Cheng Y., Qian H., Xie Y., Yao W. Membrane damage mechanism contributes to inhibition of trans-cinnamaldehyde on Penicillium italicum using Surface-Enhanced Raman Spectroscopy (SERS) Sci. Rep. 2019;9:490. doi: 10.1038/s41598-018-36989-7. PubMed DOI PMC

Beltrami L.V.R., Bandeira J.A.V., Scienza L.C., Zattera A.J. Biodegradable composites: Morphological, chemical, thermal, and mechanical properties of composites of poly(hydroxybutyrate-co-hydroxyvalerate) with curaua fibers after exposure to simulated soil. J. Appl. Polym. Sci. 2014;131:8769–8776. doi: 10.1002/app.40712. DOI

da Costa R.C., Daitx T.S., Mauler R.S., da Silva N.M., Miotto M., Crespo J.S., Carli L.N. Poly(hydroxybutyrate-co-hydroxyvalerate)-based nanocomposites for antimicrobial active food packaging containing oregano essential oil. Food Packag. Shelf Life. 2020;26:100602. doi: 10.1016/j.fpsl.2020.100602. DOI

Marcet I., Weng S., Sáez-Orviz S., Rendueles M., Díaz M. Production and characterisation of biodegradable PLA nanoparticles loaded with thymol to improve its antimicrobial effect. J. Food Eng. 2018;239:26–32. doi: 10.1016/j.jfoodeng.2018.06.030. DOI

Šašinková D., Serbruyns L., Julinová M., FayyazBakhsh A., De Wilde B., Koutný M. Evaluation of the biodegradation of polymeric materials in the freshwater environment—An attempt to prolong and accelerate the biodegradation experiment. Polym. Degrad. Stab. 2022;203:110085. doi: 10.1016/j.polymdegradstab.2022.110085. DOI

Dambolena J.S., López A.G., Cánepa M.C., Theumer M.G., Zygadlo J.A., Rubinstein H.R. Inhibitory effect of cyclic terpenes (limonene, menthol, menthone and thymol) on Fusarium verticillioides MRC 826 growth and fumonisin B1 biosynthesis. Toxicon. 2008;51:37–44. doi: 10.1016/j.toxicon.2007.07.005. PubMed DOI

Swiontek Brzezinka M., Richert A., Kalwasińska A., Świątczak J., Deja-Sikora E., Walczak M., Michalska-Sionkowska M., Piekarska K., Kaczmarek-Szczepańska B. Microbial degradation of polyhydroxybutyrate with embedded polyhexamethylene guanidine derivatives. Int. J. Biol. Macromol. 2021;187:309–318. doi: 10.1016/j.ijbiomac.2021.07.135. PubMed DOI

Fernandes M., Salvador A., Alves M.M., Vicente A.A. Factors affecting polyhydroxyalkanoates biodegradation in soil. Polym. Degrad. Stab. 2020;182:109408. doi: 10.1016/j.polymdegradstab.2020.109408. DOI

Sharma B., Jain P. Deciphering the advances in bioaugmentation of plastic wastes. J. Clean. Prod. 2020;275:123241. doi: 10.1016/j.jclepro.2020.123241. DOI

Zhou L., He H., Li M.c., Huang S., Mei C., Wu Q. Enhancing mechanical properties of poly(lactic acid) through its in-situ crosslinking with maleic anhydride-modified cellulose nanocrystals from cottonseed hulls. Ind. Crops Prod. 2018;112:449–459. doi: 10.1016/j.indcrop.2017.12.044. DOI