MINI REVIEW article

Front. Bioeng. Biotechnol., 19 July 2022

Sec. Bioprocess Engineering

Volume 10 - 2022 | https://doi.org/10.3389/fbioe.2022.966598

Advances and trends in microbial production of polyhydroxyalkanoates and their building blocks

  • 1. Key Laboratory of Plateau Ecology and Agriculture, Qinghai University, Xining, QH, China

  • 2. School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China

  • 3. Institute for Environmental Biotechnology, Department of Agrobiotechnology, University of Natural Resources and Life Sciences, Tulln, Austria

Abstract

With the rapid development of synthetic biology, a variety of biopolymers can be obtained by recombinant microorganisms. Polyhydroxyalkanoates (PHA) is one of the most popular one with promising material properties, such as biodegradability and biocompatibility against the petrol-based plastics. This study reviews the recent studies focusing on the microbial synthesis of PHA, including chassis engineering, pathways engineering for various substrates utilization and PHA monomer synthesis, and PHA synthase modification. In particular, advances in metabolic engineering of dominant workhorses, for example Halomonas, Ralstonia eutropha, Escherichia coli and Pseudomonas, with outstanding PHA accumulation capability, were summarized and discussed, providing a full landscape of diverse PHA biosynthesis. Meanwhile, we also introduced the recent efforts focusing on structural analysis and mutagenesis of PHA synthase, which significantly determines the polymerization activity of varied monomer structures and PHA molecular weight. Besides, perspectives and solutions were thus proposed for achieving scale-up PHA of low cost with customized material property in the coming future.

Introduction

Polyhydroxyalkanoates (PHAs) is a series of polyesters synthesized by different microbes (), which have been widely used as bio-plastics for replacing petrol-based plastic due to their outstanding biodegradability and biocompatibility. Accordingly, PHA can be divided into three categories () including short-, medium- and long- chain-length PHAs, namely SCL-, MCL- and LCL-PHA, respectively. Of which, the monomers of SCL-, MCL- and LCL-PHA generally contain 2–5, 6–14 and over 15 carbon atoms, respectively. Because of the competitive material properties, PHA has attracted growing attentions of commercial interests in different application areas, such as medical implant (), cosmetic beads (), packaging (), agricultural film (), textile (), feeding additives () and so on. In the past decades, intensive efforts have been made to generate various PHA productions consisting of diverse polymerized units with different carbon-chain-length and structures by genetically modified bacterial (), such as Halomonas spp. (; ), Ralstonia eutropha (; ; ), Escherichia coli (; ; ), Pseudomonas spp (; ; ) and so on (; ). Therefore, over 150 types of PHAs have been obtained including homopolymers (PHB, poly-3-hydroxybutyrate) (), random- and/or block- copolymers such as poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (P34HB), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) (), poly(3-hydroxybutyrate-co-3-hydroxyhexonate) (PHBHHx) (), etc. (). To date, many building blocks, including rational designed enzymes (; ), fine-tuned metabolic pathways towards monomer synthesis () and genetically engineered chassis of predominant PHA accumulation performance (; ), have been developed for sufficient PHA synthesis using a variate of substrates.

In particular, scale-up industrial production lines for various PHA manufacturing have been recently launched or established by several companies, for example, MedPHA (operating production line of 1,000 ton/year PHB and/or P34HB, China) (), PhaBuilder (10,000 ton/year, under construction, China) (), Tianan (3,000 ton/year PHBV, China) (), Tepha (P4HB for medical uses, United States) (), Danimer Scientific (6,000 ton/year PHBHHx, United State) (), Keneka (5,000 ton/year PHBHHx, Japan) (). However, the production cost of PHA still challenges for wide range commercial uses. Therefore, many solutions have been proposed and developed to reduce the industrial cost of PHA, including high cell density fermentation based on optimized feeding solution (), non-sterile open fermentation process based on recombinant halophiles (), cell factory engineering for effective utilization of low-cost carbon sources (; ), carbon fixation engineering for the improved conversion rate from glucose to PHA (), co-production of PHA and value-added chemicals (; ) and so on.

Therefore, this study summarized recent advances of various PHA production and industrial trends thereof. Additionally, major building blocks, including representative workhorses, metabolic pathways and critical enzymes, for PHA synthesis have been reviewed and discussed. This study provides an entire landscape of PHA productions powered by synthetic biology, as well as perspectives focusing on cost-effective PHA manufacturing in the coming future.

Workhorses for PHA production

Halomonas bluephagenesis TD01

Halomonas bluephagenesis TD01 (H. bluephagenesis), a natural PHB producer isolated from salt lake (), has been recently developed as a versatile chassis for PHA productions and value added chemicals, which exemplifies a cost-effective biomanufacturing paradigm based on next generation industrial biotechnology (NGIB) enabling non-sterile open fermentation process under high salt and high pH condition (). Currently, the genetically reprogrammed H. bluephagenesis can produce various PHA polymers, including PHB (), PHBV (), P34HB () and PHBP (poly-3-hydroxybutyrate-co-3-hydroxypropionate) () using glucose, starch, gluconate and structural related carbon sources for corresponding monomer synthesis whenever necessary, for example, 4HB from γ-butyrolactone (GBL), 3HP from 1,3-propanediol, 3HV from propionate, etc. Notably, pilot-scale production of PHB and P34HB have succeeded in a 5,000-L bioreactor, yielding up to 100 g/L dry cell mass (DCM) containing 60–70 wt% PHA content with over 30% cost reduction (). Besides, engineering electron transport system could significantly improve the supplementation of NADH (), overexpression of Vitreoscilla hemoglobin (VHb) protein led to improved oxygen uptake efficiency (), deficiency of outer membrane synthesis enabled sufficient production yield of PHA from glucose and simplified cell lysis (), manipulation of cell morphology also resulted in self-flocculation separation process (). Moreover, different genetic parts and tools have been established allowing for rational engineering of H. bluephagenesis (). These efforts have proved successful in building a high-performing workhorse for PHA production based on NGIB. Additionally, many other Halomonas strains were also successfully developed for PHA synthesis, such as Halomonas campanesis LS21 (), Halomonas elongate DSM2581 (), Halomonas pacifica ASL10 () and so on, illustrating the great potential of halophiles used as PHA producers.

Ralstonia eutropha

Ralstonia eutropha H16 (Cupriavidus necator) is a well-studied PHA producer from glucose, glycerol, palm oil and other fatty acids (FAs) (). In addition to short chain length PHA synthesis, R. eutropha H16 has been engineered to produce varied copolymers consisting of SCL-monomer (3HB) and MCL-monomers, such as 3HHx, 3HO (3-hydroxyoctanoate), 3HDD (3-hydroxydodecanoate) and so on (). In previous studies, genetic editing tools for chromosomal engineering was established based on CRISPR/Cas9 system and Cre/LoxP integrase system (). An electroporation approach was developed in recombinant R. eutropha H16 allowing for sufficient and high-through clone construction (). More importantly, over 200 g/L DCM with over 70 wt% PHA accumulation can be obtained by R. eutropha H16 and its derivates during fed-batch fermentation conducted in the lab- (<10-L) and/or pilot- (>100-L) scale bioreactors under strictly sterilized conditions (). Moreover, industrial productions of PHB, PHBV and PHBHHx based on recombinant R. eutropha H6 have been achieved by several companies. Therefore, R. eutropha H16 is expected to be a prominent chassis for PHA productions, especially for PHBHHx, however, high production cost remains challenging ().

Escherichia coli

Escherichia coli (E. coli), such BL21, JM109, etc., are well-studied model chassis that have clear genetic background and effective genetic tools for cell factory engineering of varied purposes, such as PHA biosynthesis. Even though E. coli is not a natural PHA producer, the heterogonous expression of phaCAB gene cluster from R. eutropha could efficiently boost carbon flux from pyruvate towards PHB synthesis. Therefore, intensive studies focusing on CO2 fixation (), pathway engineering () and feeding solution design of fed-batch fermentation () have been performed to generate enhanced production yield of PHB. Besides, E. coli is an ideal workhorse for studying the novel-type PHA synthesis, such as copolymers of 3HB and lactate, glycolic acid, 4-hydroxybutyrate, 5-hydroxyvalerate and other monomers with functional groups (). Specifically, the DCM and PHA content reached up to 194 g/L and 73 wt% by recombinant E. coli grown in fed-batch fermentation condition (), which shows promising performance in PHA accumulation.

Pseudomonas

Pseudomonas, including P. putida KT2440, P. entomophila, etc. have been recently engineered to be dominant producers of PHA copolymers consist of 3HB and MCL- and LCL-3HAs due to their strong FAs metabolism involved in β-oxidation cycle and de novo FAs synthesis pathways. Currently, PHA copolymers are composed of 3HB, 4HB, 3HV, 3HHx, 3HHp (3-hydroxyheptanoate), 3HO (3-hydroxyoctanoate), 3HD (3-hydroxydecanoate), etc. could be obtained by metabolically engineered Pseudomonas strains (). Many PHA synthases able to polymerize MCL- and LCL-3HA into polymers were thus identified from different Pseudomonas strains (; ; ; ). Notably, an effective platform was developed for producing full spectrum of PHAs, which contain SCl-, MCL, LCL- 3HAs and monomers carrying carbon-carbon double bones, with over 90% increase in production yield based on recombinant P. entomophila (). Moreover, higher DCM, reaching over 70 g/L, was also achieved by Pseudomonas leveraging fed-batch fermentation process optimization (). These efforts demonstrate proven success in scalable tailor-made PHA synthesis of varied functions by reprogrammed Pseudomonas.

Additionally, various attempts have been carried out to achieve PHA synthesis based on different hosts, such as Alcaligenes (H W ), Bacillus (), Burkholderia (), microalgae (), Salinivibrio (; ), Marinobacterium (), Vibrio alginolyticus () and so on, using diverse carbon sources including sucrose, propionate, carbon dioxide, volatile fatty acids, etc. It is important to note that the highest resultant DCM reached up to 281 g/L with 232 g/L PHB accumulation by Alcaligenes eutrophus, a natural PHB producer of high cell density growth and effective PHA accumulation, during a 74 h fed-batch fermentation conducted in a 60-L bioreactor (H W ).

Metabolic pathways for PHA synthesis

The biosynthesis pathways of most PHA monomers from varied carbon sources like glucose, fatty acids, etc. are mainly related to essential carbon metabolic pathways, such as glycolysis, β-oxidation and de novo fatty acid synthesis (Figure 1). Besides, using structurally related carbon sources as precursors is an alternative strategy to generate diverse PHA copolymers consist of different monomers, including 4HB from γ-butyrolactone (GBL)/1,4-butanediol (BDO), 3HV from propionate, 3HP from 1,3-propionediol (PDO), middle- and long-chain length 3HA from different fatty acids with corresponding carbon atoms and so on, which have significant impact on the material property (). Therefore, a wide variety of PHA homo- and co-polymers can be obtained by engineered microbes by feeding customized feedstocks (Figure 1).

FIGURE 1

PHA from structure-unrelated carbon sources

Glucose is a widely used feedstock in biomanufacturing. Similarly, intensive studies have been carried out for generating different PHA using glucose as the sole carbon source by metabolically engineered microorganisms. To date, many metabolic pathways have been mined and refined as significant building blocks for rewiring glucose-derived fluxes towards various monomers, such as converting pyruvate into2HB-CoA () and LA-CoA (), acetyl-CoA into 3HB-CoA and 3HP-CoA (), succinyl-CoA into 3HV-CoA () and 4HB-CoA (), respectively. Interestingly, starch (), volatile fatty acids like acetate (), waste gluconate (), the byproduct of glucose processing, were also used to culture engineered Halomonas and Pseudomonas to achieve cost-effective PHA productions (Figure 1).

In addition to glucose, building blocks for many other carbon sources metabolism, such as glycerol, sucrose, xylose, C1 compounds, etc., have been constructed to synthesize PHA. Specifically, the highest PHA accumulation, reaching 38.9 wt% with 0.34 g/L/h of productivity have been achieved by engineered P. putida KT2440 ( Fu et al. produced MCL-PHA also could be obtained by grown on chemical-grade glycerol (PG) and biodiesel-derived waste glycerol (WG) as sole carbon sources (). Moreover, recombinant strains including P. putida S12 and R. eutropha harboring expression vessel containing isomerase (XylA) and xylulokinase (XylB) have been constructed by and , respectively, to produce PHA using xylose as sole carbon source (). Similarly, a sucrose-favored P. putida strain was also developed for PHA synthesis from sucrose only (). More importantly, due to the growing interests of global carbon neutral, many bacterial like P. furiosus and R. eutropha B8562 were engineered to produce PHA polymers containing 3HP and 3HB units, respectively, using CO2 as carbon source (; ). Besides, biosynthesis pathways for PHA synthesis from CH4 were also established based on many hydrogen-oxidizing bacteria (). In summary, metabolic engineering of microbes is able to achieve targeted PHA synthesis from different structure-unrelated carbon sources.

PHA from structure-related carbon sources

For most MCL- and LCL-PHA synthesis, supplementation of structure-related fatty acids in the medium is a commonly used strategy to grow recombinant cells with defected β-oxidation cycle or reprogramed de novo fatty acids synthesis pathways (). For instance, a wide range of PHA copolymers composed of 3HB and MCL-/LCL-3HA units containing carbon atoms numbered from 6 to 18, even with carbon-carbon double bone, have been achieved by engineered Pseudomonas, yielding over 100% increase of production titer (). Besides, many short chain length (SCL) PHA units were also produced from structure-related carbon sources used as precursors, such as 4HB synthesis from 1,4-propanediol (PDO) and β-butyrolactone (GBL) (), 3HP synthesis from 1,3-propionediol (PDO) (), 5HV synthesis from 1,5-pentanediol (), as well as functional group monomer like 4HPhLA synthesized from tyrosine (), etc. Recently, high production yield of P34HB with 4HB molar ratio from 5 mol% to 26 mol% has been achieved by recombinant H. bluephagenesis based on NGIB platform, which also demonstrated the success in scale-up production of low cost conducted in 5-to-200 m³ fermenters (). Notably, used engineered Escherichia coli to synthesize aromatic polyester, P(3HB-co-D-phenylacetate), from tyrosine, of which the molar ratio of D-phenylacetate monomer reaches up to 47.7 mol% (). Moreover, tailor-made copolymers, as well as block copolymers, consisting of two, three and even more units could be easily obtained by designing the supplementation formula of target precursors and feeding strategy thereof ().

Engineering tools and strategies for sufficient PHA synthesis

In addition to the biosynthesis pathway construction for diverse PHA productions, many metabolic engineering tools including high resolution gene expression tuning (), high throughput library construction (; ), constitutive and inducible promoter design (; ) and so on have been developed for constructing effective PHA producing strains. Moreover, a carbon fixation of CO2 was established in E. coli to generate an increased bioconversion rate of glucose towards PHB (). Modulating the NADH levels and its regeneration pathways could also show proven effects on PHA accumulation in both E. coli and Halomonas strains with PHA content increased up to 90 wt% (). Interestingly, cell morphology control is an efficient strategy to obtain enhanced PHA accumulation with significantly improved substrate conversion rate (). Manipulation of PHA granule size also demonstrated strong significance for downstream processing, which dramatically reduce the energy consumption of cell separation and PHA purification (). Therefore, the downstream-inspired engineering of microbes also displays great significance in cost-reduction for industrial PHA biomanufacturing.

PHA synthase

PHA synthase (PhaC) is an important building block for PHA synthesis. Generally, there are four major types of PhaC, namely Class-I/II/III/IV (), which have been identified from different PHA producing strains (Table 1). Of which, Class-I, -III and IV generally show higher activity on short-chain-length (SCL) monomers (C3-C5) polymerization, while Class-II has higher specificity to medium- and long- chain-length (M/LCL) monomers containing 6–18 carbon atoms, namely C6-C18 (). Specifically, most Class-I PHA synthases, such as PhaCs from R. eutropha (), Alcaligenes latus (), Aeromonas Caviae and Chromobacterium sp. (), not only show effective activity on SCL PHA accumulation including 3HB, 3HP, 4HB and 3HV units, but also display polymerization capability of MCL PHA like 3HHx ().

TABLE 1

ClassSourceExpression hostPHAPHA contentDCM (g/L)References
IRalstonia eutrophaA. eutrophus (NCIMB 11599)PHB83 wt%281
IRalstonia eutrophaC. necator Re2133P (3HB-co-18.5 mol% 3HHx)52 wt%1.1
IRalstonia eutrophaRalstonia eutropha PHB-4P (3HB-co-5 mol% 3HP-co-10 mol% 5HV)12 wt%0.3
IRalstonia eutrophaE. coli JM109SGIKP (3HB-co-7.89 mol% 4HB)78 wt%11.6
IRalstonia eutropha H16Pseudomonas putida KTOY08∆GCP (3HB-b-80.31 mol% 4HB)50 wt%5.5
IRalstonia eutrophaE. coliP (3HB-co-84 mol% 3HP)42 wt%5
IAeromonas caviaeRalstonia eutropha PHB-4P (3HB-co-35 mol% 3HV-co-3HHx)80 wt%7.1
IChromobacterium spE. coliP3HP40 wt%-
IAeromonas caviaeBurkholderia sp. USM (JCM15050)P (3HB-co-34 mol% 3HV-co-6 mol% 3HHx)86 wt%1.5
IIPseudomonas sp. 61–3Pseudomonas entomophilaP (3HB-co-14 mol% 3HPD)60 wt%9
IIPseudomonas sp. 61–3E. coli W3110P (11 mol% 3HHx-co-39 mol% 3HO-co-50 mol% 3HD)4.8 wt%1.7
IIPseudomonas sp. MBEL 6–19E. coli XL1-BlueP (38.1 mol% PhLA-co-3HB)55 wt%13.9
IIPseudomonas sp. MBEL 6–19E. coli XL1-BlueP (88.2 mol%LA-co-11.8 mol%GA)12.6 wt%-
IIPseudomonasE. coliP (8.2 mol%GA-co-16.3 mol%GA-co-66.1 mol%3HB-co-9.4 mol%4HB)72.89 wt%19.6
IIPseudomonas mendocinaPseudomonas mendocinaP (3HB-co-3HO-co-3HD)77 wt%3.7
IIPseudomonas oleovorans ATCC 29347Pseudomonas oleovorans ATCC 29347mcl-PHA63 wt%18
IIIThiocapsa pfennigiiPseudomonas putida GPp104P (3HB-co-3HV-co-15.4 mol% 4HV)52 wt%20
IVBacillus cereus FA11Bacillus cereus FA11P (3HB-co-6.49 mol% 3HV)49 wt%6.2
IVBacillus cereus YB-4E. coli JM109PHB36 wt%3.0
-Halomonas bluephagenesis TD01Halomonas bluephagenesis TD01P (3HB-co-16.1 mol% 4HB)61 wt%82.6
-Burkholderia sacchari DSM 17165Burkholderia sacchari DSM 17165P (3HB-co-1.6 mol% 4HB)73 wt%72.9)
-Cupriavidus malaysiensis USMAA2-4Cupriavidus malaysiensis USMAA1020P (3HB-co-99 mol% 4HB)92 wt%50.4

Different PHA synthases identified from natural PHA producing strains.

-Not classified PHA synthase.

Recently, many efforts have been made to modified the polymerization activity of PHA synthase, including protein structure analysis (), mutagenesis () and fusion of functional domains from different PhaCs (), to generate high-performing PHA synthase. For instance, report the first crystal structure of Ralstonia eutropha PHA synthase at 1.8 Å resolution and structure-based mechanisms for PHA polymerization, RePhaC1 contains two distinct domains, the N-terminal (RePhaC1ND) and C-terminal domains (RePhaC1CD), and exists as a dimer (). Furthermore, site-directed mutation was employed to generate PhaC mutants, namely PhaC61-3 and PhaC1437, based on PHA synthases from Pseudomonas sp. 61–3 and Pseudomonas sp. MBEL 6–19, respectively, which show wide substrate specificity to both SCL and M/LCL monomers (), as well as monomers with a particular structure like benzene ring (). Moreover, an artificial PHA synthase, PhaCAR, was constructed by hybridizing the C-terminal of PhaCAC from Aermonas Caviae and N-terminal of PhaCRE from R. eutropha (Cupriavidus necator), enabling effective accumulation for block copolymers containing 2-hydroxybutyrate (2HB) ();

Conclusion and perspective

In this study, we highlighted the global trends of industrial PHA productions reported by different companies and start-up teams, and briefly summarized and discussed the advances of different building blocks focusing on PHA synthase, biosynthesis pathways of SCL-, MCL- and LCL-PHA, dominant PHA workhorses of industrial potential and optimization strategies for effective PHA synthesis. This study provides an overview of PHA biosynthesis from enzyme engineering, cell factory design, towards scale-up bio-manufacturing. However, more attempts are still required to achieve further cost-reduction and improved material properties of tailor-made PHAs against the petrol-based plastics.

Statements

Author contributions

QG, HY, and CW contributed equally in this study. X-YX, K-XL, YgL, S-YH, MN, YaL, and J-WY wrote the manuscript, J-WY, YaL, and MN proposed the idea and revised the manuscript.

Funding

This research is supported by National Natural Science Foundation of China (Grant No. 32001029), National Natural Science Foundation of Qinghai Province (Grant No. 2020-ZJ-759), Guangdong Basic and Applied Basic Research Foundation (Grant No. 2020A1515111079), State Key Laboratory of Plateau Ecology and Agriculture, Qinghai University (Grant No. 2021-KF-09), and Tsinghua University-INDITEX Sustainable Development Fund (Grant No. TISD201907).

Conflict of interest

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Publisher’s note

All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.

References

  • 1

    Abd El-MalekF.FaragA.OmarS.KhairyH. (2020). Polyhydroxyalkanoates (PHA) from Halomonas pacifica ASL10 and Halomonas salifodiane ASL11 isolated from Mariout salt lakes. Int. J. Biol. Macromol.161, 13181328. 10.1016/j.ijbiomac.2020.07.258

  • 2

    AntonioR. V.SteinbüchelA.RehmB. H. A. (2000). Analysis of in vivo substrate specificity of the PHA synthase from Ralstonia eutropha: Formation of novel copolyesters in recombinant Escherichia coli. FEMS Microbiol. Lett.182, 111117. 10.1111/j.1574-6968.2000.tb08883.x

  • 3

    BhatiaS. K.GuravR.ChoiT.-R.JungH.-R.YangS.-Y.SongH.-S.et al (2019). Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) production from engineered Ralstonia eutropha using synthetic and anaerobically digested food waste derived volatile fatty acids. Int. J. Biol. Macromol.133, 110. 10.1016/j.ijbiomac.2019.04.083

  • 4

    BhatiaS. K.YiD. H.KimH. J.JeonJ. M.KimY. H.SathiyanarayananG.et al (2015). Overexpression of succinyl-CoA synthase for poly (3-hydroxybutyrate-co-3-hydroxyvalerate) production in engineered Escherichia coli BL21(DE3). J. Appl. Microbiol.119, 724735. 10.1111/jam.12880

  • 5

    Borrero-De AcunaJ. M.RohdeM.SaldiasC.Poblete-CastroI. (2021). Fed-batch mcl- polyhydroxyalkanoates production in Pseudomonas putida KT2440 and DeltaphaZ mutant on biodiesel-derived crude glycerol. Fron t Bioeng. Biotechnol.9, 642023. 10.3389/fbioe.2021.642023

  • 6

    CavalheiroJ. M.De AlmeidaM. C.Da FonsecaM. M.De CarvalhoC. C. (2012). Adaptation of Cupriavidus necator to conditions favoring polyhydroxyalkanoate production. J. Biotechnol.164, 309317. 10.1016/j.jbiotec.2013.01.009

  • 7

    CerroneF.DuaneG.CaseyE.DavisR.BeltonI.KennyS. T.et al (2014). Fed-batch strategies using butyrate for high cell density cultivation of Pseudomonas putida and its use as a biocatalyst. Appl. Microbiol. Biotechnol.98, 92179228. 10.1007/s00253-014-5989-8

  • 8

    ChanasitW.HodgsonB.SudeshK.UmsakulK. (2016). Efficient production of polyhydroxyalkanoates (PHAs) from Pseudomonas mendocina PSU using a biodiesel liquid waste (BLW) as the sole carbon source. Biosci. Biotechnol. Biochem.80, 14401450. 10.1080/09168451.2016.1158628

  • 9

    CheeJ.-Y.LauN.-S.SamianM.-R.TsugeT.SudeshK. (2012). Expression of Aeromonas caviae polyhydroxyalkanoate synthase gene in Burkholderia sp. USM (JCM15050) enables the biosynthesis of SCL-MCL PHA from palm oil products. J. Appl. Microbiol.112, 4554. 10.1111/j.1365-2672.2011.05189.x

  • 10

    ChekM. F.HiroeA.HakoshimaT.SudeshK.TaguchiS. (2019). PHA synthase (PhaC): Interpreting the functions of bioplastic-producing enzyme from a structural perspective. Appl. Microbiol. Biotechnol.103, 11311141. 10.1007/s00253-018-9538-8

  • 11

    ChekM. F.KimS. Y.MoriT.ArsadH.SamianM. R.SudeshK.et al (2017). Structure of polyhydroxyalkanoate (PHA) synthase PhaC from Chromobacterium sp. USM2, producing biodegradable plastics. Sci. Rep.7, 5312. 10.1038/s41598-017-05509-4

  • 12

    ChenG.-Q.PatelM. K. (2012). Plastics derived from biological sources: Present and future: A technical and environmental review. Chem. Rev.112, 20822099. 10.1021/cr200162d

  • 13

    ChenG.-Q.WuQ. (2005). The application of polyhydroxyalkanoates as tissue engineering materials. Biomaterials26, 65656578. 10.1016/j.biomaterials.2005.04.036

  • 14

    ChenG. Q. (2009). A microbial polyhydroxyalkanoates (PHA) based bio- and materials industry. Chem. Soc. Rev.38, 2434. 10.1039/b812677c

  • 15

    ChenG. Q.JiangX. R. (2017). Engineering bacteria for enhanced polyhydroxyalkanoates (PHA) biosynthesis. Synth. Syst. Biotechnol.2, 192197. 10.1016/j.synbio.2017.09.001

  • 16

    ChenG. Q.JiangX. R.GuoY. (2016). Synthetic biology of microbes synthesizing polyhydroxyalkanoates (PHA). Synth. Syst. Biotechnol.1, 236242. 10.1016/j.synbio.2016.09.006

  • 17

    ChenX.YinJ.YeJ.ZhangH.CheX.MaY.et al (2017). Engineering Halomonas bluephagenesis TD01 for non-sterile production of poly(3-hydroxybutyrate-co-4-hydroxybutyrate). Bioresour. Technol.244, 534541. 10.1016/j.biortech.2017.07.149

  • 18

    ChoiS. Y.ChoI. J.LeeY.KimY.-J.KimK.-J.LeeS. Y.et al (2020). Bacterial polyesters: Microbial polyhydroxyalkanoates and nonnatural polyesters (adv. Mater. 35/2020). Adv. Mat.32, 2070264. 10.1002/adma.202070264

  • 19

    ChoiS. Y.ParkS. J.KimW. J.YangJ. E.LeeH.ShinJ.et al (2016). One-step fermentative production of poly(lactate-co-glycolate) from carbohydrates in Escherichia coli. Nat. Biotechnol.34, 435440. 10.1038/nbt.3485

  • 20

    ChuahJ.-A.YamadaM.TaguchiS.SudeshK.DoiY.NumataK.et al (2013). Biosynthesis and characterization of polyhydroxyalkanoate containing 5-hydroxyvalerate units: Effects of 5HV units on biodegradability, cytotoxicity, mechanical and thermal properties. Polym. Degrad. Stab.98, 331338. 10.1016/j.polymdegradstab.2012.09.008

  • 21

    ChungA. L.JinH. L.HuangL. J.YeH. M.ChenJ. C.WuQ.et al (2011). Biosynthesis and characterization of poly(3-hydroxydodecanoate) by beta-oxidation inhibited mutant of Pseudomonas entomophila L48. Biomacromolecules12, 35593566. 10.1021/bm200770m

  • 22

    CiesielskiS.MozejkoJ.PrzybylekG. (2010). The influence of nitrogen limitation on mcl-PHA synthesis by two newly isolated strains of Pseudomonas sp. J. Ind. Microbiol. Biotechnol.37, 511520. 10.1007/s10295-010-0698-5

  • 23

    CostaS. S.MirandaA. L.De MoraisM. G.CostaJ. a. V.DruzianJ. I. (2019). Microalgae as source of polyhydroxyalkanoates (PHAs) - a review. Int. J. Biol. Macromol.131, 536547. 10.1016/j.ijbiomac.2019.03.099

  • 24

    FuJ.SharmaU.SparlingR.CicekN.LevinD. B. (2014a). Evaluation of medium-chain-length polyhydroxyalkanoate production by Pseudomonas putida LS46 using biodiesel by-product streams. Can. J. Microbiol.60, 461468. 10.1139/cjm-2014-0108

  • 25

    FuX. Z.TanD.AibaidulaG.WuQ.ChenJ. C.ChenG. Q.et al (2014b). Development of Halomonas TD01 as a host for open production of chemicals. Metab. Eng.23, 7891. 10.1016/j.ymben.2014.02.006

  • 26

    GorenfloV.SchmackG.VogelR.SteinbüchelA. (2001). Development of a process for the biotechnological large-scale production of 4-hydroxyvalerate-containing polyesters and characterization of their physical and mechanical properties. Biomacromolecules2, 4557. 10.1021/bm0000992

  • 27

    Gutierrez-GomezU.Servin-GonzalezL.Soberon-ChavezG. (2019). Role of beta-oxidation and de novo fatty acid synthesis in the production of rhamnolipids and polyhydroxyalkanoates by Pseudomonas aeruginosa. Appl. Microbiol. Biotechnol.103, 37533760. 10.1007/s00253-019-09734-x

  • 28

    HobmeierK.LoweH.LiefeldtS.KremlingA.Pfluger-GrauK. (2020). A nitrate-blind P. Putida strain boosts PHA production in a synthetic mixed culture. Front. Bioeng. Biotechnol.8, 486. 10.3389/fbioe.2020.00486

  • 29

    HuD.ChungA.-L.WuL.-P.ZhangX.WuQ.ChenJ.-C.et al (2011). Biosynthesis and characterization of polyhydroxyalkanoate block copolymer P3HB-b-P4HB. Biomacromolecules12, 31663173. 10.1021/bm200660k

  • 30

    HyakutakeM.TomizawaS.MizunoK.AbeH.TsugeT. (2014). Alcoholytic cleavage of polyhydroxyalkanoate chains by class IV synthases induced by endogenous and exogenous ethanol. Appl. Environ. Microbiol.80, 14211429. 10.1128/aem.03576-13

  • 31

    IlhamM.NakanomoriS.KiharaT.HokamuraA.MatsusakiH.TsugeT.et al (2014). Characterization of polyhydroxyalkanoate synthases from Halomonas sp. O-1 and Halomonas elongata DSM2581: Site-directed mutagenesis and recombinant expression. Polym. Degrad. Stab.109, 416423. 10.1016/j.polymdegradstab.2014.04.024

  • 32

    JiangX. R.YanX.YuL. P.LiuX. Y.ChenG. Q. (2021). Hyperproduction of 3-hydroxypropionate by Halomonas bluephagenesis. Nat. Commun.12, 1513. 10.1038/s41467-021-21632-3

  • 33

    Jong-Il ChoiS. Y. L.LeeS. Y.HanK. (1998). Kyuboem HanCloning of the Alcaligenes latus polyhydroxyalkanoate biosynthesis genes and use of these genes for enhanced production of poly(3-hydroxybutyrate) in Escherichia coli. Appl. Environ. Microbiol.1, 48974903. 10.1128/aem.64.12.4897-4903.1998

  • 34

    JungK.HazenbergW.PrietoM.WitholtB. (2001). Two-stage continuous process development for the production of medium-chain-length poly(3-hydroxyalkanoates). Biotechnol. Bioeng.72, 1924. 10.1002/1097-0290(20010105)72:1<19::aid-bit3>3.0.co;2-b

  • 35

    KellerM. W.SchutG. J.LipscombG. L.MenonA. L.IwuchukwuI. J.LeukoT. T.et al (2013). Exploiting microbial hyperthermophilicity to produce an industrial chemical, using hydrogen and carbon dioxide. Proc. Natl. Acad. Sci. U. S. A.110, 58405845. 10.1073/pnas.1222607110

  • 36

    Khosravi-DaraniK.MokhtariZ. B.AmaiT.TanakaK. (2013). Microbial production of poly(hydroxybutyrate) from C(1) carbon sources. Appl. Microbiol. Biotechnol.97, 14071424. 10.1007/s00253-012-4649-0

  • 37

    KimJ.KimY. J.ChoiS. Y.LeeS. Y.KimK. J. (2017). Crystal structure of Ralstonia eutropha polyhydroxyalkanoate synthase C-terminal domain and reaction mechanisms. Biotechnol. J.1, 1600648. 10.1002/biot.201600648

  • 38

    KourmentzaC.PlácidoJ.VenetsaneasN.Burniol-FigolsA.VarroneC.GavalaH. N.et al (2017). Recent advances and challenges towards sustainable polyhydroxyalkanoate (PHA) production. Bioengineering4, 55. 10.3390/bioengineering4020055

  • 39

    LanL.-H.ZhaoH.ChenJ.-C.ChenG.-Q. (2016). Engineering Halomonas spp. as A low-cost production host for production of bio-surfactant protein PhaP. Biotechnol. J.11, 15951604. 10.1002/biot.201600459

  • 40

    LeeJ.ParkH. J.MoonM.LeeJ.-S.MinK. (2021). Recent progress and challenges in microbial polyhydroxybutyrate (PHB) production from CO2 as a sustainable feedstock: A state-of-the-art review. Bioresour. Technol.339, 125616. 10.1016/j.biortech.2021.125616

  • 41

    LiH. F.WangM. R.TianL. Y.LiZ. J. (2021a). Production of polyhydroxyalkanoates (PHAs) by Vibrio alginolyticus strains isolated from salt fields. Molecules26 (20), 6283. 10.3390/molecules26206283

  • 42

    LiM.ChenX.CheX.ZhangH.WuL. P.DuH.et al (2019). Engineering Pseudomonas entomophila for synthesis of copolymers with defined fractions of 3-hydroxybutyrate and medium-chain-length 3-hydroxyalkanoates. Metab. Eng.52, 253262. 10.1016/j.ymben.2018.12.007

  • 43

    LiM.MaY.ZhangX.ZhangL.ChenX.YeJ. W.et al (2021b). Tailor-made polyhydroxyalkanoates by reconstructing Pseudomonas entomophila. Adv. Mat.33, e2102766. 10.1002/adma.202102766

  • 44

    LiT.GuoY.-Y.QiaoG.-Q.ChenG.-Q. (2016). Microbial synthesis of 5-aminolevulinic acid and its coproduction with polyhydroxybutyrate. ACS Synth. Biol.5, 12641274. 10.1021/acssynbio.6b00105

  • 45

    LiZ. J.QiaoK.CheX. M.StephanopoulosG. (2017). Metabolic engineering of Escherichia coli for the synthesis of the quadripolymer poly(glycolate-co-lactate-co-3-hydroxybutyrate-co-4-hydroxybutyrate) from glucose. Metab. Eng.44, 3844. 10.1016/j.ymben.2017.09.003

  • 46

    LiangP.ZhangY.XuB.ZhaoY.LiuX.GaoW.et al (2020). Deletion of genomic islands in the Pseudomonas putida KT2440 genome can create an optimal chassis for synthetic biology applications. Microb. Cell. Fact.19, 70. 10.1186/s12934-020-01329-w

  • 47

    LimH.ChuahJ.-A.ChekM. F.TanH. T.HakoshimaT.SudeshK.et al (2021). Identification of regions affecting enzyme activity, substrate binding, dimer stabilization and polyhydroxyalkanoate (PHA) granule morphology in the PHA synthase of Aquitalea sp. USM4. Int. J. Biol. Macromol.186, 414423. 10.1016/j.ijbiomac.2021.07.041

  • 48

    LinZ.ZhangY.YuanQ.LiuQ.LiY.WangZ.et al (2015). Metabolic engineering of Escherichia coli for poly (3-hydroxybutyrate) production via threonine bypass. Microb. Cell. Fact.14, 185. 10.1186/s12934-015-0369-3

  • 49

    Linares-PasténJ. A.Sabet-AzadR.PessinaL.SardariR. R. R.IbrahimM. H. A.Hatti-KaulR.et al (2015). Efficient poly(3-hydroxypropionate) production from glycerol using Lactobacillus reuteri and recombinant Escherichia coli harboring L. reuteri propionaldehyde dehydrogenase and Chromobacterium sp. PHA synthase genes. Bioresour. Technol.180, 172176. 10.1016/j.biortech.2014.12.099

  • 50

    LingC.QiaoG.-Q.ShuaiB.-W.SongK.-N.YaoW.-X.JiangX.-R.et al (2019). Engineering self-flocculating Halomonas campaniensis for wastewaterless open and continuous fermentation. Biotechnol. Bioeng.116, 805815. 10.1002/bit.26897

  • 51

    LingC.QiaoG. Q.ShuaiB. W.OlavarriaK.YinJ.XiangR. J.et al (2018). Engineering NADH/NAD(+) ratio in Halomonas bluephagenesis for enhanced production of polyhydroxyalkanoates (PHA). Metab. Eng.49, 275286. 10.1016/j.ymben.2018.09.007

  • 52

    LvL.RenY. L.ChenJ. C.WuQ.ChenG. Q. (2015). Application of CRISPRi for prokaryotic metabolic engineering involving multiple genes, a case study: Controllable P(3HB-co-4HB) biosynthesis. Metab. Eng.29, 160168. 10.1016/j.ymben.2015.03.013

  • 53

    MaH.ZhaoY.HuangW.ZhangL.WuF.YeJ.et al (2020). Rational flux-tuning of Halomonas bluephagenesis for co-production of bioplastic PHB and ectoine. Nat. Commun.11, 3313. 10.1038/s41467-020-17223-3

  • 54

    MartinD. P.WilliamsS. F. (2003). Medical applications of poly-4-hydroxybutyrate: A strong flexible absorbable biomaterial. Biochem. Eng. J.16, 97105. 10.1016/s1369-703x(03)00040-8

  • 55

    MatsumotoK. I.TakaseK.YamamotoY.DoiY.TaguchiS. (2009). Chimeric enzyme composed of polyhydroxyalkanoate (PHA) synthases from Ralstonia eutropha and Aeromonas caviae enhances production of PHAs in recombinant Escherichia coli. Biomacromolecules10, 682685. 10.1021/bm801386j

  • 56

    MehrpouyaM.VahabiH.BarlettaM.LaheurteP.LangloisV. (2021). Additive manufacturing of polyhydroxyalkanoates (PHAs) biopolymers: Materials, printing techniques, and applications. Mater. Sci. Eng. C127, 112216. 10.1016/j.msec.2021.112216

  • 57

    MeijnenJ. P.De WindeJ. H.RuijssenaarsH. J. (2008). Engineering Pseudomonas putida S12 for efficient utilization of D-xylose and L-arabinose. Appl. Environ. Microbiol.74, 50315037. 10.1128/aem.00924-08

  • 58

    MengD. C.WangY.WuL. P.ShenR.ChenJ. C.WuQ.et al (2015). Production of poly(3-hydroxypropionate) and poly(3-hydroxybutyrate-co-3-hydroxypropionate) from glucose by engineering Escherichia coli. Metab. Eng.29, 189195. 10.1016/j.ymben.2015.03.015

  • 59

    Miranda De Sousa DiasM.KollerM.PuppiD.MorelliA.ChielliniF.BrauneggG. (2017). Fed-batch synthesis of poly(3-hydroxybutyrate) and poly(3-hydroxybutyrate-co-4-hydroxybutyrate) from sucrose and 4-hydroxybutyrate precursors by Burkholderia sacchari strain DSM 17165. Bioengineering4, 36. 10.3390/bioengineering4020036

  • 60

    MizunoS.EndaY.SaikaA.HiroeA.TsugeT. (2018). Biosynthesis of polyhydroxyalkanoates containing 2-hydroxy-4-methylvalerate and 2-hydroxy-3-phenylpropionate units from a related or unrelated carbon source. J. Biosci. Bioeng.125, 295300. 10.1016/j.jbiosc.2017.10.010

  • 61

    ModiS.KoellingK.VodovotzY. (2011). Assessment of PHB with varying hydroxyvalerate content for potential packaging applications. Eur. Polym. J.47, 179186. 10.1016/j.eurpolymj.2010.11.010

  • 62

    Możejko-CiesielskaJ.KiewiszR. (2016). Bacterial polyhydroxyalkanoates: Still fabulous?Microbiol. Res.192, 271282. 10.1016/j.micres.2016.07.010

  • 63

    MuruganP.GanC.-Y.SudeshK. (2017). Biosynthesis of P(3HB-co-3HHx) with improved molecular weights from a mixture of palm olein and fructose by Cupriavidus necator Re2058/pCB113. Int. J. Biol. Macromol.102, 11121119. 10.1016/j.ijbiomac.2017.05.006

  • 64

    NorhafiniH.HuongK.-H.AmirulA. A. (2019). High PHA density fed-batch cultivation strategies for 4HB-rich P(3HB-co-4HB) copolymer production by transformant Cupriavidus malaysiensis USMAA1020. Int. J. Biol. Macromol.125, 10241032. 10.1016/j.ijbiomac.2018.12.121

  • 65

    ObručaS.DvořákP.SedláčekP.KollerM.SedlářK.PernicováI.et al (202210790). Polyhydroxyalkanoates synthesis by halophiles and thermophiles: Towards sustainable production of microbial bioplastics. Biotechnol. Adv.58, 107906. 10.1016/j.biotechadv.2022.107906

  • 66

    OuyangP.WangH.HajnalI.WuQ.GuoY.ChenG. Q.et al (2018). Increasing oxygen availability for improving poly(3-hydroxybutyrate) production by Halomonas. Metab. Eng.45, 2031. 10.1016/j.ymben.2017.11.006

  • 67

    PacholakA.GaoZ.-L.GongX.-Y.KaczorekE.CuiY.-W. (2021). The metabolic pathways of polyhydroxyalkanoates and exopolysaccharides synthesized by Haloferax mediterranei in response to elevated salinity. J. Proteomics232, 104065. 10.1016/j.jprot.2020.104065

  • 68

    PanichJ.FongB.SingerS. W. (2021). Metabolic engineering of cupriavidus necator H16 for sustainable biofuels from CO2. Trends Biotechnol.39, 412424. 10.1016/j.tibtech.2021.01.001

  • 69

    ParkS. J.AhnW. S.GreenP. R.LeeS. Y. (2001). Production of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) by metabolically engineered Escherichia coli strains. Biomacromolecules2, 248254. 10.1021/bm000105u

  • 70

    ParkS. J.KimT. W.KimM. K.LeeS. Y.LimS.-C. (2012a). Advanced bacterial polyhydroxyalkanoates: Towards a versatile and sustainable platform for unnatural tailor-made polyesters. Biotechnol. Adv.30, 11961206. 10.1016/j.biotechadv.2011.11.007

  • 71

    ParkS. J.LeeS. Y.KimT. W.JungY. K.YangT. H. (2012b). Biosynthesis of lactate-containing polyesters by metabolically engineered bacteria. Biotechnol. J.7, 199212. 10.1002/biot.201100070

  • 72

    ParkS. J.LeeT. W.LimS. C.KimT. W.LeeH.KimM. K.et al (2012c). Biosynthesis of polyhydroxyalkanoates containing 2-hydroxybutyrate from unrelated carbon source by metabolically engineered Escherichia coli. Appl. Microbiol. Biotechnol.93, 273283. 10.1007/s00253-011-3530-x

  • 73

    ParkS. J.ParkJ. P.LeeS. Y. (2002). Metabolic engineering of Escherichia coli for the production of medium-chain-length polyhydroxyalkanoates rich in specific monomers. FEMS Microbiol. Lett.214, 217222. 10.1111/j.1574-6968.2002.tb11350.x

  • 74

    PrietoA.EscapaI. F.MartinezV.DinjaskiN.HerenciasC.De La PenaF.et al (2016). A holistic view of polyhydroxyalkanoate metabolism in Pseudomonas putida. Environ. Microbiol.18, 341357. 10.1111/1462-2920.12760

  • 75

    RabergM.VolodinaE.LinK.SteinbuchelA. (2018). Ralstonia eutropha H16 in progress: Applications beside PHAs and establishment as production platform by advanced genetic tools. Crit. Rev. Biotechnol.38, 494510. 10.1080/07388551.2017.1369933

  • 76

    RyuH. W.SK. H.ChangY. K.ChangH. N. (1996). Production of poly(3-hydroxybutyrate) by high cell density fed-batch culture of Alcaligenes eutrophus with phospate limitation. Biotechnol. Bioeng.55 (51), 2832. 10.1002/(sici)1097-0290(19970705)55:1<28::aid-bit4>3.0.co;2-z

  • 77

    RyuH. W.HahnS. K.ChangY. K.ChangH. N. (1997). Production of poly(3‐hydroxybutyrate) by high cell density fed‐batch culture of Alcaligenes eutrophus with phospate limitation. Biotechnol. Bioeng.55, 2832. 10.1002/(sici)1097-0290(19970705)55:1<28::aid-bit4>3.0.co;2-z

  • 78

    SalehizadehH.YanN.FarnoodR. (2020). Recent advances in microbial CO2 fixation and conversion to value-added products. Chem. Eng. J.390, 124584. 10.1016/j.cej.2020.124584

  • 79

    SathiyanarayananG.KiranG. S.SelvinJ.SaibabaG. (2013). Optimization of polyhydroxybutyrate production by marine Bacillus megaterium MSBN04 under solid state culture. Int. J. Biol. Macromol.60, 253261. 10.1016/j.ijbiomac.2013.05.031

  • 80

    ScheelR. A.HoT.KageyamaY.MasisakJ.MckenneyS.LundgrenB. R.et al (2021). Optimizing a fed-batch high-density fermentation process for medium chain-length poly(3-hydroxyalkanoates) in Escherichia coli. Front. Bioeng. Biotechnol.9, 618259. 10.3389/fbioe.2021.618259

  • 81

    ShenR.YinJ.YeJ.-W.XiangR.-J.NingZ.-Y.HuangW.-Z.et al (2018). Promoter engineering for enhanced P (3HB-co-4HB) production by Halomonas bluephagenesis. ACS Synth. Biol.7, 18971906. 10.1021/acssynbio.8b00102

  • 82

    SilvaF.CampanariS.MatteoS.ValentinoF.MajoneM.VillanoM.et al (2017). Impact of nitrogen feeding regulation on polyhydroxyalkanoates production by mixed microbial cultures. N. Biotechnol.37, 9098. 10.1016/j.nbt.2016.07.013

  • 83

    SteinbüchelA. (2001). Perspectives for biotechnological production and utilization of biopolymers: Metabolic engineering of polyhydroxyalkanoate biosynthesis pathways as a successful example. Macromol. Biosci.1, 124. 10.1002/1616-5195(200101)1:1<1::aid-mabi1>3.0.co;2-b

  • 84

    SudeshK.AbeH.DoiY. (2000). Synthesis, structure and properties of polyhydroxyalkanoates: Biological polyesters. Prog. Polym. Sci.25, 15031555. 10.1016/s0079-6700(00)00035-6

  • 85

    SudoM.HoriC.OoiT.MizunoS.TsugeT.MatsumotoK. I.et al (2020). Synergy of valine and threonine supplementation on poly(2-hydroxybutyrate-block-3-hydroxybutyrate) synthesis in engineered Escherichia coli expressing chimeric polyhydroxyalkanoate synthase. J. Biosci. Bioeng.129, 302306. 10.1016/j.jbiosc.2019.09.018

  • 86

    TanD.XueY. S.AibaidulaG.ChenG. Q. (2011). Unsterile and continuous production of polyhydroxybutyrate by Halomonas TD01. Bioresour. Technol.102, 81308136. 10.1016/j.biortech.2011.05.068

  • 87

    TanI. K. P.FoongC. P.TanH. T.LimH.ZainN. A.TanY. C.et al (2020). Polyhydroxyalkanoate (PHA) synthase genes and PHA-associated gene clusters in Pseudomonas spp. and Janthinobacterium spp. isolated from Antarctica. J. Biotechnol.313, 1828. 10.1016/j.jbiotec.2020.03.006

  • 88

    TanakaK.YoshidaK.OritaI.FukuiT. (2021). Biosynthesis of poly (3-hydroxybutyrate-co-3-hydroxyhexanoate) from CO2 by a recombinant cupriavidusnecator. Bioengineering8, 179. 10.3390/bioengineering8110179

  • 89

    TariqA.HameedA.BokhariH.MasoodF. (2015). Is atomic rearrangement of type IV PHA synthases responsible for increased PHA production?J. Biomol. Struct. Dyn.33, 12251238. 10.1080/07391102.2014.941401

  • 90

    UshimaruK.MotodaY.NumataK.TsugeT. (2014). Phasin proteins activate Aeromonas caviae polyhydroxyalkanoate (PHA) synthase but not Ralstonia eutropha PHA synthase. Appl. Environ. Microbiol.80, 28672873. 10.1128/aem.04179-13

  • 91

    Van ThuocD.LoanT. T.TrungT. A.Van QuyenN.TungQ. N.TienP. Q.et al (2020). Genome mining reveals the biosynthetic pathways of polyhydroxyalkanoate and ectoines of the halophilic strain Salinivibrio proteolyticus M318 isolated from fermented shrimp paste. Mar. Biotechnol. (NY).22, 651660. 10.1007/s10126-020-09986-z

  • 92

    Van ThuocD.MyD. N.LoanT. T.SudeshK. (2019). Utilization of waste fish oil and glycerol as carbon sources for polyhydroxyalkanoate production by Salinivibrio sp. M318. Int. J. Biol. Macromol.141, 885892. 10.1016/j.ijbiomac.2019.09.063

  • 93

    VolovaT.TrusovaM.KalachevaG.KozhevnicovI. (2006). Physiological–biochemical properties and the ability to synthesize polyhydroxyalkanoates of the glucose-utilizing strain of the hydrogen bacterium Ralstonia eutropha B8562. Appl. Microbiol. Biotechnol.73, 429433. 10.1007/s00253-006-0460-0

  • 94

    WangM. R.LiH. F.YiJ. J.TaoS. Y.LiZ. J. (2022). Production of polyhydroxyalkanoates by three novel species of Marinobacterium. Int. J. Biol. Macromol.195, 255263. 10.1016/j.ijbiomac.2021.12.019

  • 95

    WangX.HanJ.-N.ZhangX.MaY.-Y.LinY.WangH.et al (2021a). Reversible thermal regulation for bifunctional dynamic control of gene expression in Escherichia coli. Nat. Commun.12, 1411. 10.1038/s41467-021-21654-x

  • 96

    WangY.WuH.JiangX.ChenG.-Q. (2014). Engineering Escherichia coli for enhanced production of poly(3-hydroxybutyrate-co-4-hydroxybutyrate) in larger cellular space. Metab. Eng.25, 183193. 10.1016/j.ymben.2014.07.010

  • 97

    WangZ.QinQ.ZhengY.LiF.ZhaoY.ChenG.-Q.et al (2021b). Engineering the permeability of Halomonas bluephagenesis enhanced its chassis properties. Metab. Eng.67, 5366. 10.1016/j.ymben.2021.05.010

  • 98

    XiongB.LiZ.LiuL.ZhaoD.ZhangX.BiC.et al (2018). Genome editing of Ralstonia eutropha using an electroporation-based CRISPR-Cas9 technique. Biotechnol. Biofuels11, 172. 10.1186/s13068-018-1170-4

  • 99

    YanX.LiuX.YuL. P.WuF.JiangX. R.ChenG. Q.et al (2022). Biosynthesis of diverse α, ω-diol-derived polyhydroxyalkanoates by engineered Halomonas bluephagenesis. Metab. Eng.72, 275288. 10.1016/j.ymben.2022.04.001

  • 100

    YangJ. E.ChoiY. J.LeeS. J.KangK. H.LeeH.OhY. H.et al (2014). Metabolic engineering of Escherichia coli for biosynthesis of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) from glucose. Appl. Microbiol. Biotechnol.98, 95104. 10.1007/s00253-013-5285-z

  • 101

    YangJ. E.ParkS. J.KimW. J.KimH. J.KimB. J.LeeH.et al (2018). One-step fermentative production of aromatic polyesters from glucose by metabolically engineered Escherichia coli strains. Nat. Commun.9, 79. 10.1038/s41467-017-02498-w

  • 102

    YangS.LiS.JiaX. (2019). Production of medium chain length polyhydroxyalkanoate from acetate by engineered Pseudomonas putida KT2440. J. Ind. Microbiol. Biotechnol.46, 793800. 10.1007/s10295-019-02159-5

  • 103

    YangT. H.KimT. W.KangH. O.LeeS. H.LeeE. J.LimS. C.et al (2010). Biosynthesis of polylactic acid and its copolymers using evolved propionate CoA transferase and PHA synthase. Biotechnol. Bioeng.105, 150160. 10.1002/bit.22547

  • 104

    YangX.LiS.JiaX. (2020). A four-microorganism three-step fermentation process for producing medium-chain-length polyhydroxyalkanoate from starch. Biotech10, 352. 10.1007/s13205-020-02347-6

  • 105

    Yao JZ.WuQ.ChenG.ZhangR. (1999). Production of polyhydroxyalkanoates by Pseudomonas nitroreducens. Antonie Leeuwenhoek75 (74), 345349. 10.1023/a:1002082303615

  • 106

    YeJ.HuD.YinJ.HuangW.XiangR.ZhangL.et al (2020). Stimulus response-based fine-tuning of polyhydroxyalkanoate pathway in Halomonas. Metab. Eng.57, 8595. 10.1016/j.ymben.2019.10.007

  • 107

    YeJ.HuangW.WangD.ChenF.YinJ.LiT.et al (2018). Pilot scale-up of poly(3-hydroxybutyrate-co-4-hydroxybutyrate) production by Halomonas bluephagenesis via cell growth adapted optimization process. Biotechnol. J.13, 1800074. 10.1002/biot.201800074

  • 108

    YeJ. W.ChenG. Q. (2021). Halomonas as a chassis. Essays Biochem.65, 393403. 10.1042/ebc20200159

  • 109

    YoungE. M.ZhaoZ.GielesenB. E.WuL.GordonD. B.RoubosJ. A.et al (2018). Iterative algorithm-guided design of massive strain libraries, applied to itaconic acid production in yeast. Metab. Eng.48, 3343. 10.1016/j.ymben.2018.05.002

  • 110

    YuL. P.YanX.ZhangX.ChenX. B.WuQ.JiangX. R.et al (2020). Biosynthesis of functional polyhydroxyalkanoates by engineered Halomonas bluephagenesis. Metab. Eng.59, 119130. 10.1016/j.ymben.2020.02.005

  • 111

    YueH.LingC.YangT.ChenX.ChenY.DengH.et al (2014). A seawater-based open and continuous process for polyhydroxyalkanoates production by recombinant Halomonas campaniensis LS21 grown in mixed substrates. Biotechnol. Biofuels7, 108. 10.1186/1754-6834-7-108

  • 112

    ZhangX.LinY.WuQ.WangY.ChenG. Q. (2020). Synthetic biology and genome-editing tools for improving PHA metabolic engineering. Trends Biotechnol.38, 689700. 10.1016/j.tibtech.2019.10.006

  • 113

    ZhouH.VonkB.RoubosJ. A.BovenbergR. A.VoigtC. A. (2015). Algorithmic co-optimization of genetic constructs and growth conditions: Application to 6-ACA, a potential nylon-6 precursor. Nucleic Acids Res.43, 1056010570. 10.1093/nar/gkv1071

  • 114

    ZhouQ.ShiZ. Y.MengD. C.WuQ.ChenJ. C.ChenG. Q.et al (2011). Production of 3-hydroxypropionate homopolymer and poly(3-hydroxypropionate-co-4-hydroxybutyrate) copolymer by recombinant Escherichia coli. Metab. Eng.13, 777785. 10.1016/j.ymben.2011.10.002

  • 115

    ZouH.ShiM.ZhangT.LiL.LiL.XianM.et al (2017). Natural and engineered polyhydroxyalkanoate (PHA) synthase: Key enzyme in biopolyester production. Appl. Microbiol. Biotechnol.101, 74177426. 10.1007/s00253-017-8485-0

Summary

Keywords

polyhydroxyalkanoates, synthetic pathway, metabolic engineering, PHA synthase, microbial production

Citation

Gao Q, Yang H, Wang C, Xie X-Y, Liu K-X, Lin Y, Han S-Y, Zhu M, Neureiter M, Lin Y and Ye J-W (2022) Advances and trends in microbial production of polyhydroxyalkanoates and their building blocks. Front. Bioeng. Biotechnol. 10:966598. doi: 10.3389/fbioe.2022.966598

Received

11 June 2022

Accepted

01 July 2022

Published

19 July 2022

Volume

10 - 2022

Edited by

Xinjun Feng, Qingdao Institute of Bioenergy and Bioprocess Technology (CAS), China

Reviewed by

Zheng-Jun Li, Beijing University of Chemical Technology, China

Dan Tan, Xi’an Jiaotong University, China

Updates

Copyright

*Correspondence: Markus Neureiter, ; Yina Lin, ; Jian-Wen Ye,

† These authors have contributed equally to this work

This article was submitted to Bioprocess Engineering, a section of the journal Frontiers in Bioengineering and Biotechnology

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